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El presente trabajo estuvo orientado a evaluar la precisión del algoritmo de análisis de imágenes Red, Green, Blue (RGB), incluido en el software TaurusWebs ®, que permite calcular el porcentaje de proteína cruda de la materia seca (%PC) de las gramíneas a partir de imágenes de las praderas tomadas por un dron acoplado con cámaras RGB. Se compararon las mediciones del %PC calculadas por el algoritmo frente a un referente, Near Infrared Reflectance Spectroscopy (NIRS), del laboratorio de Corpoica (Agrosavia), calibrado para gramíneas. Se tomaron 42 muestras para NIRS, 18 de gramíneas de trópico alto en Cundinamarca: kikuyo, Pennisetum clandestinum; falsa poa, Holcus lanatus; pasto brasilero, Phalaris arundinacea y 24 de trópico bajo en Tolima, Colombia: pangola, Digitaria decumbens; pará, Brachiaria mutica; bermuda, Cynodon dactylon y colosuana, Bothriochloa pertusa. Los resultados del NIRS se compararon contra las evaluaciones hechas con el algoritmo de las imágenes de las gramíneas provenientes del mismo potrero donde se tomaron las muestras. Los resultados fueron comparados usando las pruebas no paramétricas de correlación de Kendall, rho=0.83 y de Kruskal Wallis. No se encontraron diferencias entre el resultado del %PC de las gramíneas medida por NIRS vs el %PC medida por el algoritmo de análisis de imágenes RGB. En conclusión, la información generada con el algoritmo se puede utilizar para trabajos de análisis del %PC en gramíneas.

The turnover of soil organic carbon (SOC) under different land uses plays an important role in terrestrial carbon (C) cycling. However, the effects of warming on C decomposition dynamics have not been resolved due to seemingly inconsistent results among different experiments. Hence, the objective of this work was to assess soil aggregate-associated C and temperature sensitivity of SOC decomposition within bulk soils and aggregates under two contrasting land management systems in subtropical southern Queensland.We examined the temperature sensitivity of SOC decomposition (Q) and activation energy required for soil C mineralization (Ea) from bulk soils (

Water allocation is a principal planning method for managing water supplies to agricultural and horticultural land in drying climates. Regulatory bodies often establish the water allocation amount, but its distribution during the irrigation season is left to the land manager’s discretion. We evaluated approaches to best manage water allocations to a warm-season turfgrass [Pennisetum clandestinum (Holst. Ex Chiov)] grown on a free-draining sand prone to surface (0–25 mm) soil water repellence in a Mediterranean climate in south-western Australia under ‘deficit irrigation’, in a two-year field study. The three factorial experiment consisted of three levels for each treatment applied to plots (10 m2) of kikuyugrass: water allocation (5000, 6250 or 7500 kL ha−1 yr−1), irrigation schedule, and soil wetting agent rate (nil, recommended ‘label’ rate, double recommended ‘label’ rate), and was replicated three times. The irrigation schedules were based on historical net evaporation at the site, and then refined monthly using in-season net evaporation data or measurements of soil water content. Kikuyugrass growth and color was adequate when irrigated using the current regional water allocation (7500 kL ha−1 yr−1) under a low wear situation and to a lesser extent when the water allocation was lowered to 6250 kL ha−1 yr−1. Application of a soil wetting agent diminished water repellence and improved kikuyugrass color for 7500 or 6250 kL ha−1 yr−1 water allocations. Distributing a water allocation based on historical monthly net evaporation rates was a simple and effective scheduling approach to maintaining a warm-season turfgrass.

This study investigated the type and quality of forages used in smallholder farms dairy in three agro-ecological zones (Mayaga and peripheral Bugesera, Eastern Savanna and Central Bugesera, and Eastern plateau) of the Eastern Province of Rwanda in the four seasons of the year. Representative farms were randomly selected from the beneficiaries of Girinka programme. Daily feed types and quantities were recorded and samples were taken for proximate analysis. The analysis of variance (ANOVA) was used to assess the differences in use and quality between zones and seasons. Twenty-two (22) types of feeds were identified across the three zones and four seasons. Roadside grasses, Napier grass ( Pennisetum Purpureum ), and Kikuyu grass ( Pennisetum clandestinum ) were the only grasses that were used in the three zones throughout the year. However, Leersia grass ( Leersia hexandra ) and Rhodes grass ( Chloris gayana ) were only used during the dry season in Eastern Savanna and Central Bugesera zone. The forages harvested from roadside and weeds were the most used (56.1%) followed by the crop residues (28.7%), while the planted forages, were the second least used forages. The only legume forage identified during the study period was Calliandra ( Calliandra Spp ) which contributed up to 0.16% of the overall dry matter intake (DMI). The DMI was higher (p 0.05) within the zones throughout the year. To enhance dairy cow productivity in the Girinka programme, there is a need for introducing and promoting new legumes, grasses, and trees in the region to improve feed supply, especially in dry seasons.

More than half of the applied conventional fertiliser nitrogen (N) in cropping systems can be lost to the environment, resulting in water and air pollution. Farming systems that ensure efficient fertiliser use are crucial to sustain crop productivity without harming the environment. One avenue to achieve this is the use of bio-fertilisers with recognised benefits for plant nutrition and soil heath. Within this area, plant growth promoting rhizobacteria (PGPR) are increasingly applied to enhance plant nutrient acquisition and assimilation. Here, we investigated if PGPR can improve fertiliser performance. We show that the addition of PGPR to soils amended with 50% organic and 50% conventional N fertilisers increased the growth of kikuyu grass (Pennisetum clandestinum), producing yields similar to those obtained using 100% conventional N fertiliser. Encouragingly, this combination also reduced mineral N leaching by 95% relative to the all conventional fertiliser treatment. These findings suggest that using organic and synthetic fertilisers together in the presence of PGPR is a promising approach for sustaining plant growth while reducing potential pollution from inefficient use of conventional N fertilisers.

Resumen Los sistemas de producción de rumiantes en Colombia están soportados en el uso de forrajes, principalmente el kikuyo en el trópico alto (Cenchrus clandestinus, previamente Pennisetum clandestinum). El objetivo de este trabajo fue recopilar la información relacionada con el kikuyo e identificar nuevos campos de investigación que permitan promover un manejo eficiente y sostenible de los sistemas de producción bovino soportados en praderas de kikuyo. Los trabajos sugieren que el kikuyo presenta gran resiliencia ante condiciones ambientales adversas, lo que lo perfilan como una especie de interés ante los nuevos escenarios de variabilidad climática. Además, la literatura reporta estrategias de manejo que promueven el aumento en la producción animal, el mejoramiento en la calidad final del producto y la disminución en el impacto sobre el ambiente. Sin embargo, el kikuyo presenta limitaciones en la respuesta agronómica y composicional que hace necesario desarrollar trabajos de investigación que permitan profundizar en el conocimiento de las relaciones entre las condiciones edafoclimáticas y de manejo que promueva el desarrollo de modelos de optimización de los sistemas de producción. Finalmente, se debe promover programas que permitan conocer las características fenotípicas y genotípicas del kikuyo y definir programas de mejoramiento genético que potencialicen la expresión de esta gramínea en condiciones ambientales específicas. Abstract Colombian ruminants’ systems are supported in grasslands, mainly kikuyu in highlands (Cenchrus clandestinus, previously Pennisetum clandestinum). The objective of this work was to compile information related to kikuyu and identify new research areas to promote an efficient and sustainable ruminants’ systems supported in kikuyu. The literature suggests that kikuyu presents great resilience to adverse environmental conditions, especially in new scenarios of climatic variability. In addition, literature reports management strategies to improve animal production, product quality and reduce environmental impact. However, kikuyu presents limitations of agronomic and compositional response, that makes necessary to develop research works that allow increase knowledge between edafo-climatic relations and management conditions to development optimization models for kikuyu production systems. Finally, it is necessary to promote phenotype and genotype studies and define genetic improvement programs to enhance grass expression under specific environmental conditions. Resumo Os sistemas de produção de ruminantes na Colômbia são baseados na utilização de forragens, principalmente kikuyo nos trópicos superiores (Cenchrus clandestinus, anteriormente Pennisetum clandestinum). O objetivo deste trabalho foi coletar informações relacionadas à kikuyo e identificar novos campos de pesquisa que promovam o manejo eficiente e sustentável de sistemas de produção bovino alimentados com pastagens de kikuyo. Estudos sugerem que o kikuyo tem grande resiliência a condições ambientais adversas, despertando grande interesse tendo em vista os novos cenários de variabilidade climática. Além disso, a literatura relata estratégias de manejo que promovem o aumento da produção animal, a melhoria na qualidade final do produto e a diminuição do impacto no meio ambiente. Entretanto, o kikuyo apresenta limitações no que diz respeito à resposta agronômica e composição necessárias para desenvolver pesquisas que aprofundem a compreensão das relações entre as condições e manejo do solo e o clima que promovam o desenvolvimento de sistemas de modelos de otimização da produção. Finalmente, devem ser desenvolvidos programas que permitam conhecer as características fenotípicas e genotípicas desta forragem, além de definir programas de melhoramento genético que potencializem a expressão dessa gramínea em condições ambientais específicas.

Bu saksı denemesi bazı sıcak iklim çim buğdaygillerinden Uganda (Cynodon dactylon x C.transvaalensis), Yengeçotu (Stenotaphrum secundatum) ve Zenci darısı’na (Pennisetum clandestinum) uygulanan farklı tuz (0-100-200-300 mM) konsantrasyonlarının verim ve beslenme durumu üzerine etkilerini incelemek amacıyla yürütülmüştür. Artan tuzluluk ile tüm çeşitlerin yeşil aksam ve kök kuru ağırlıkları azalmıştır. Aynı şekilde tuzluluk arttıkça en temel üç besin maddesi olan N, P, K element içerikleri de olumsuz bir şekilde etkilenmiştir. Bu çalışmanın sonuçlarına dayanarak, Zenci darısı (Pennisetum clandestinum) çimi 200 mM ve 300 mM tuz uygulamalarından etkilenmesine rağmen, incelenen diğer bitkilere göre tuzluluğa daha yüksek dayanım göstermiştir.

La provincia de Ubaté es una de las regiones lecheras más importantes de Colombia y sus pasturas están representadas principalmente por pasto kikuyo (Cenchrus clandestinus Hochst. ex Chiov.), luego, la necesidad de mejorar el uso de esta pastura es uno de los retos más importantes, debido a que la utilización de ésta se ha realizado de manera tradicional y muy pocos productores se han preocupado por optimizar su uso. Para determinar si la mayor producción de biomasa y el mayor rendimiento de nutrientes digestibles del Kikuyo se presenta cuando los rebrotes se encuentren en una proporción de 5 hojas vivas, durante un año en cuatro explotaciones lecheras representativas de dos altitudes de la provincia de Ubaté, Colombia (Ubaté 2500 m s.n.m., Tausa 2900 m s.n.m.), se aplicaron cuatro tratamientos o momentos de corte con una repetición (4, 5, 6 y 7 hojas por rebrote) en cada finca. Se utilizó un diseño experimental de bloques completamente al azar por altitud con análisis de experimentos en serie entre altitudes. Se encontraron diferencias significativas para las variables estructurales, el tratamiento de 4 hojas es diferente (39 días) del tratamiento de 7 hojas (66 días). En cuanto a la altitud también se encontraron diferencias significativas entre los 2500 m s.n.m. (34 - 58 días) y los 2900 m s.n.m. (50 -70 días). En términos generales a 2500 m s.n.m. se necesitan de 8 días en promedio para el desarrollo de 1 hoja nueva, distinto a los 2900 m s.n.m. dado que se necesitan en promedio 10 días para el desarrollo de 1 hoja nueva. A medida que aumenta el número de hojas el %PC disminuye (P0,05) 4 hojas (19%) y 7 hojas (17%), el %DIVMS también disminuye (P0,05) un 5% entre estos dos tratamientos. A través del tiempo hay una mayor producción acumulada de biomasa, nutrientes digestibles totales y megacalorías de energía neta de lactancia. A los 2500 m s.n.m. el tratamiento de 5 hojas acumula una mayor producción para todas las variables y es diferente significativamente sobre el tratamiento de 7 hojas. Se concluyó que el momento adecuado de cosecha a los 2500 m s.n.m. son 5 hojas por rebrote y a los 2900 corresponde entre 4 y 6 hojas por rebrote. Abstract: The Ubaté province is one of the most important dairy regions in Colombia and his pastures are represented by Kikuyo grass (Cenchrus clandestinus Hochst, Ex Chiov.), Then, the importance to improve the use of this pasture is one of the challenges more important, because the use of this pasture, has been done in a traditional way and dairy farmers have been concerned about optimizing its use. To prove if the highest production of biomass and the highest yield of digestible nutrients of the Kikuyu occurs when the tiller are in a proportion of 5 live leaves, during a year in four dairy farms representative of the province of Ubaté (Ubaté 2500 m a.s.l., Tausa 2900 m a.s.l.), four treatments with one repetition (4, 5, 6 and 7 leaves per regrowth) were applied in eighth experimental plots for each farm. An experimental design of blocks completely randomized by altitude with analysis of experiments in series between altitudes was used. Differences were found for the structural variables, the treatment of 4 leaves is different (39 days) from the treatment of 7 leaves (66 days). In terms of altitude, differences between 2500 m a.s.l. (34 - 58 days) and 2900 m a.s.l. (50 -70 days). In general terms at 2500 m a.s.l. 8 days are needed on average for the growth of 1 new leaf, different to 2900 m a.s.l. in this altitude it take an average of 10 days for the growth of 1 new leaf. As the number of leaves increases the content of %CP decreases (P 0.05) 4 leaves (19%) and 7 leaves (17%). Also the content of %IVDMD also decreases (P 0.05) 5% between these two treatments. Through time is a higher production of biomass accumulated, total digestible nutrients and mega calories of net energy of lactation. At 2500 m a.s.l the treatment of 5 leaves accumulates more production for all the variables and is significantly different of the treatment of 7 leaves. This study concluded that the optimum moment of the harvest kikuyu at 2500 m s.n.m. corresponds to 5 leaves per tiller and in the altitude of 2900 m a.s.l correspond to 4 to 6 leaves per tiller. Maestría

This study was conducted in the municipality of Guachucal, Department of Narino, existing farming systems were characterized, analyzed the function and structure of the tree component and relate tree cover with the intensification of production systems. Stratified farms according to its area, where three strata were obtained: I (0.5 - 3 has), II (3.1 - 6 has) and III (> 6 has). Then applied a stratified sampling using the formula of Ballesteros, with a total of 200 farms, which were classified according to each stratum. To obtain the different diagnoses was a semi-structured survey, which was analyzed using a statistical analysis of major components, multiple correspondence (ACM) and Pearson correlations. The predominantly traditional production system is the perennial ligneous forestry - potato-pasture-bovine milk, characterized by being made with tree species such as: pandala (Clethra sp.), capuli (Prunus cerotina), alder (Alnus acuminata), acacia (Acacia decurrens), eucalyptus (Eucalyptus globulus), Cypress (Cupressus sp.). Regarding grasses predominated the mixture of Pennisetum clandestinum, Holcus lanatus, Lolium multiflorum, and Trifolium repens L; and dominates the race of Holstein cattle. He was also obtained that 95% of farms are paddocks, 100% present mix of native and improved pastures, where the 70.5% manages a production system no stanchion, t 19% and 10.5% stanchion. In the hedgerows, the most representative species of the farms were acacia (Acacia melanoxylom) pine (Pinus patula), used mainly for firewood, poles and wood. The relationship of tree cover with the intensification of production systems is given in a positive way by the area of the estate, area in pasture, cows in production, calf nursing, total production of milk per day, and costs of livestock. Key words: Forestry system, multivariate analysis, hoists cover

The study evaluated small-scale dairy systems with continuous grazing of pastures based on three temperate grasses festulolium (FL), tall fescue (TF), and perennial ryegrass (RG), compared with subtropical kikuyu grass (KG). All pastures were associated with white clover (Trifolium repens L.). Twelve multiparous Holstein cows were assigned to a 4 × 4 Latin square replicated three times with 14-day experimental periods. Sampling and analyses of pastures, concentrates, and animal variables followed standard procedures. FL showed a significantly (p 0.05) higher mean sward height, but there were no differences (p 0.05) in net herbage accumulation. There were significant differences (p 0.05) among pastures for CP, NDF, ADF, in vitro digestibility of OM (IVOMD), and estimated metabolizable energy (eME). There were no differences (p 0.05) between treatments for milk yield and composition, live weight, or body condition score. There were significant differences (p 0.05) in fatty acid values for pastures in C14:0, C16:1, and C18:3n3. There were significant differences between treatments (p 0.05) in milk contents for C18:0, C18:1t11, and C18:2c9t11. Grazing FL, TF, RG, or KY pastures showed no differences in milk yields. Higher values for C18:0, C18:1t11, and C18:2c9t11 were detected in KY, RG, and TF. RG had significantly higher MUFA than FL and higher PUFA than TF. A value under 65% of SFA, a ratio of n-6/n-3 lower than 4, and an atherogenic index of 1.7 are indicators of milk with beneficial effects for human health.

Since 2005, a serious emerging disease called fairway patch has occurred on the fairways, tees and green surrounds of a number of golf courses in New South Wales, Queensland, Victoria and Western Australia. It occurs most commonly on couch or bermudagrass (Cynodon dactylon) but has also been found on kikuyu (Pennisetum clandestinum) fairways at one golf course in Sydney. The disease begins as small patches (5–10 cm diam.) of yellow to tan-coloured grass. The patches enlarge into tan-coloured rings up to 1 m in diameter, which often coalesce to form unsightly brown networks of dead and dying grass. The patches are present all the year round but are most pronounced from late spring to late autumn. Fungal isolation from diseased roots and pathogenicity tests have proven that a slow-growing (ca. 2 mm/day on PDA at 25 °C), dark, septate, non-sporulating fungus is the cause of fairway patch. Phylogenetic analysis of the pathogen’s rDNA ITS and partial 28S sequences has shown that it is a new taxon and is described as Phialocephala bamuru P.T.W. Wong & C. Dong sp. nov. It belongs to a heterogeneous clade that includes Phialocephala, Acephala, Vibrissea, Phaeomollisia and Mollisia spp., but, as it is phylogenetically closest to Phialocephala spp. (94–95 % ITS affinities), it has been described as a Phialocephala species although it has not been shown to produce spores in culture. Research is continuing to study the biology and ecology of this ectotrophic root-infecting fungal pathogen and develop practical strategies to manage the disease.

Summary Distributions of invasive alien species (IAS) are well documented all over the world, and roads are considered one of the main means by which IAS spread. Bolivia is one of a few countries for which there are no such studies. For this reason, we determined the number of exotic plant species in the vicinity of roads near the city of La Paz, Bolivia. We distinguish two types of roads, paved and gravel roads, and in their vicinity, we studied the floristic composition in three regions, differing mainly in altitude: high Andes, puna grassland and dry valley. We found three exotic species in the vicinity of roads in the high Andes, five in puna grassland and 10 in the dry valley. We found 13 exotic species along gravel roads and nine along paved roads, whilst there was a trend for such species to be more abundant close to the roads than further away. Pennisetum clandestinum was the most frequently recorded exotic species in all regions and associated with both types of roads. The results indicate that exotic species are quite frequent along roads in Bolivia and present a potential threat as invasive species. Therefore, it may be necessary to take measures to prevent IAS from spreading further.

Restoring degraded mesic-montane forests represents a major challenge in maintaining functioning ecosystems throughout the tropics. A key example of this lies in Hawai'i, where restoring native koa (Acacia koa, A. Gray) forests are a top conservation and forestry priority because of the critical habitat and high-value timber products that they provide. Efforts to restore koa forests, however, are directly impeded by extensive, non- native kikuyu grass (Pennisetum clandestinum Hochst. ex Chiov.) swards occupying deforested montane landscapes. In this study, we implemented a combination of grass suppression and selection of koa seedling stocktypes to measure outplanting performance in a naturalized site on the island of Maui. Seedlings were grown in a nursery in two root container sizes (111 and 207 cm 3 ) and subsequently outplanted into grass-dominated plots that were either untreated or suppressed with a high-rate herbicide combination of imazapyr and glyphosate (1.7 kg a.i. ha -1 , respectively), 30 days prior to planting. Across all treatments, seedling survival was high ((95 %). Thirty months after planting, trees from the larger stocktype had significantly greater growth in height and root-collar diameter. Initial grass suppression resulted in trees that were 34 % taller with 66 % larger root-collar diameters after 30 months. Herbicide treated plots also had significantly higher leaf area indices (2.6 vs. 1.8 m 2 m -2 ), indicative of higher photosynthetic capacity and canopy closure. Grass suppression increased soil temperature along with soil moisture in the first year followed by a dramatic drop in moisture corresponding to large growth

Kikuyu (Pennisetum clandestinum) is a highly productive pasture species that supports high stocking rates and milk production per hectare, but production per cow is low due to low nutritive value. The aim of this study was to determine the grazing capacity, milk production and milk composition of dairy cows grazing irrigated kikuyu over-sown with Italian (Lolium multiflorum var. italicum), Westerwolds (L. multiflorum var. westerwoldicum) or perennial ryegrass (L. perenne) during autumn. The grazing capacity of the kikuyu–ryegrass systems was lower during winter and autumn than during spring and summer, with the seasonal grazing capacity of the perennial ryegrass treatment more evenly distributed than that of the Italian and Westerwolds ryegrass treatments. The perennial ryegrass treatment had a lower butterfat and milk production per lactation than the Italian and Westerwolds ryegrass treatments, but had the highest milk solids and fat corrected milk production per hectare. The latter was a result of the higher annual grazing capacity achieved by the perennial ryegrass treatment. It was concluded that because kikuyu over-sown with perennial ryegrass supported a higher number of animals and had a more evenly distributed fodder-flow, it achieved higher animal production per hectare than kikuyu over-sown with annual ryegrass varieties.Keywords: fat-corrected milk, Lolium, milk solids, pasture, Pennisetum clandestinum

a b s t r a c t A 120 days of growth study was conducted on goats to assess the comparative effect of feeding two species of tanniferous oak leaves (Quercus semecarpifolia and Quercus leucotri- cophora) having varied levels of tannin on nutrient utilization, growth performance and gastrointestinal nematode load in goats. Eighteen crossbred (Chegu × Jamunapari) goats of 7-9 months old (body weight, 15.99 ± 1.53 kg) were divided into three groups of six in each in a completely randomized block design. Animals in all the three groups were fed similar concentrate mixture with different roughage sources (30:70). Animals were fed green grass (PS, Pennisetum clandestinum) in group T1 and oak leaves i.e. Quercus semecarpifolia (QS) and Quercus leucotricophora (QL) in groups T2 and T3, respectively. The level of condensed tannin (g kg−1 dry matter (DM)) was found to be more in QL (34) than QS (17), whereas the level of hydrolysable tannin (HT) (g kg −1 DM) was more in QS (61) than QL (31). A metabolic trial of six days duration was conducted after 90 days of growth trial. Dry matter intake (DMI) through roughage and total DM intake (g d −1 ) in oak leaves fed groups (T2 and T3) was higher (P < 0.05) than grass fed group (T1). Feeding of QL in T3 had a depressing effect (P < 0.05) on DM, organic matter (OM), crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF) and total carbohydrate (TCHO) digestibility as compared to feeding of PC. DM and OM digestibility were lower (P < 0.05) in T2 fed QS whereas CP, NDF, ADF and TCHO digestibility were at par with control (T1). However, EE digestibility was higher (P < 0.05) in T2. Daily nutrient intake per kilogram metabolic body weight in both the oak leaves fed groups was higher (P < 0.01) than green grass fed group. Nitrogen and calcium balances (g d −1 ) and its efficiency of utilization were higher (P < 0.05) in oak leaves fed group. Aver- age daily gain (g d−1) was higher in T2 (32.5) and T3 (25.7) compared to T1 (13.5). Feed gain ratio (DMI/body weight gain) was better in T2 (22.9) than T1 (39.5) but at par with T3 (29.9) (P < 0.05). Feeding of oak leaves (10-19 g kg−1 DM CT in diet) significantly reduced (P < 0.01) the gastrointestinal nematode load in goats. It can be concluded that feeding of oak leaves (Quercus spp.) to kids was beneficial in augmenting nutrient utilization, growth performance and feed efficiency as compared to animals fed green grass (PS). However, goats fed tannin (g kg −1

El pasto Pennisetum clandestinum es la base de los sistemas lecheros de las regiones de alta montaña en Colombia. Debido a sus requerimientos de fertilización es vital encontrar alternativas sustentables para su manejo. En este estudios se utilizaron cuatro cepas nativas de los géneros Azotobacter, Pseudomonas, Micrococcus y Bacillus, aisladas de P. clandestinum. Se caracterizaron las capacidades de promoción de crecimiento in vitro, las cuales fueron solubilización de fosfatos, producción de compuestos indólicos y síntesis de sideróforos; seguido de un ensayo bajo condiciones de invernadero utilizando una dosis de 50% de fosfato tricálcico más cada cepa bacteriana. Después de dos meses se midió el potencial de las bacterias para incrementar la altura de la planta, longitud radical, peso foliar y radicular en P. clandestinum. Los resultados indicaron que las cuatro cepas cuentan con capacidades de promoción in vitro. La cepa Azotobacter beijerinckii KA206 + 50% fosfato tricálcico incrementó significativamente (p≤ 0.05) las variables agronómicas evaluadas. Estos resultados sobrepasaron el tratamiento con 50% de la dosis de fertilización fosfatada en términos de longitud y peso seco de la raíz. Las cuatro cepas arrojaron resultados significativamente diferentes (p≤ 0.05). Este resultado preliminar sugiere una alternativa factible que podría reducir la fertilización fosfatada con fuentes de baja solubilización en la producción lechera en sistemas de agricultura sustentable. The grass Pennisetum clandestinum is the base of the dairy systems in high mountain regions in Colombia. Due to its fertilization requirements it is vital to find sustainable alterna-tives for its management. In this study, four native strains of the genera Azotobacter, Pseudomonas, Micrococcus andBacillus, isolated from P. clandestinum were used. Charac-terization of growth promotion ability in vitro such as phos-phorus solubilization, production of indole compounds and siderophores synthesis was made for all strains, followed by a test under greenhouse conditions using 50% tricalci-um phosphate plus each bacterium. After two months the bacteria,s potential to increment height, radical length, leaf and root weight in P. clandestinum was measured. The re-sults indicated that the four strains have the ability for plant growth promotion. The treatment with the strain Azotobacter beijerinckii KA206 + 50% tricalcium phosphate increased significantly (p≤ 0.05) the assessed agronomical variables. These results surpassed the treatment with a 50% phosphate fertilization in terms of plant performance regarding roots length and dry weight. The four strains exhibited results that were significantly different (p≤ 0.05). These preliminary re-sults suggest the existence of a feasible alternative that could reduce the phosphate fertilization with sources of low solu-bilization for the dairy production in sustainable agriculture systems. Incluye referencias bibliográficas

Metal contamination is a recurring problem in Peru, caused mainly by mine tailings from a past active mining activity. The Ancash region has the largest number of environmental liabilities, which mobilizes high levels of metals and acid drainages into soils and freshwater sources, posing a standing risk on human and environmental health. Native plant species spontaneously growing on naturally acidified soils and acid mine tailings show a unique tolerance to high metal concentrations and are thus potential candidates for soil phytoremediation. However, little is known about their propagation capacity and metal accumulation under controlled conditions. In this study, we aimed at characterizing nine native plant species, previously identified as potential hyperaccumulators, from areas impacted by mine tailings in the Ancash region. Plants were grown on mine soils under greenhouse conditions during 5 months, after which the concentration of Cd, Cu, Ni, Pb, and Zn was analyzed in roots, shoots, and soils. The bioaccumulation (BAF) and translocation factor (TF) were calculated to determine the amount of each metal accumulated in the roots and shoots and to identify which species could be better suited for phytoremediation purposes. Soil samples contained high Cd (6.50-49.80 mg/kg), Cu (159.50-1187.00 mg/kg), Ni (3.50-8.70 mg/kg), Pb (1707.00-4243.00 mg/kg), and Zn (909.00-7100.00 mg/kg) concentrations exceeding national environmental quality standards. After exposure to mine tailings, concentrations of metals in shoots were highest in Werneria nubigena (Cd, 16.68 mg/kg; Cu, 41.36 mg/kg; Ni, 26.85 mg/kg; Zn, 1691.03 mg/kg), Pennisetum clandestinum (Pb, 236.86 mg/kg), and Medicago lupulina (Zn, 1078.10 mg/kg). Metal concentrations in the roots were highest in Juncus bufonius (Cd, 34.34 mg/kg; Cu, 251.07 mg/kg; Ni, 6.60 mg/kg; Pb, 718.44 mg/kg) and M. lupulina (Zn, 2415.73 mg/kg). The greatest BAF was calculated for W. nubigena (Cd, 1.92; Cu, 1.20; Ni, 6.50; Zn, 3.50) and J. bufonius (Ni, 3.02; Zn, 1.30); BCF for Calamagrostis recta (Cd, 1.09; Cu, 1.80; Ni, 1.09), J. bufonius (Cd, 3.91; Cu, 1.79; Ni, 18.36), and Achyrocline alata (Ni, 137; Zn, 1.85); and TF for W. nubigena (Cd, 2.36; Cu, 1.70; Ni, 2.42; Pb, 1.17; Zn, 1.43), A. alata (Cd, 1.14; Pb, 1.94), J. bufonius (Ni, 2.72; Zn, 1.63), and P. clandestinum (Zn, 1.14). Our results suggest that these plant species have a great potential for soil phytoremediation, given their capability to accumulate and transfer metals and their tolerance to highly metal-polluted environments in the Andean region.

Made available in DSpace on 2018-12-11T17:15:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-10-03 The challenge of agricultural sector is to reduce greenhouse gas (GHG) emissions while increasing food, fiber and energy production without jeopardizing environmental integrity. In the Andean zone of Colombia, there is a growing need to develop GHG mitigation techniques associated with milk production. The present study focuses on GHG emissions and potential sinks associated with milk production scenarios in the Andean zone of Colombia. The scenarios considered were as follows: conventional agriculture of Pennisetum clandestinum in rotation with potatoes (PRP), improved pastures of Lolium multiflorum (IP) and silvopastoral system of P. clandestinum in association with Acacia decurrens and Trifolium repens (SPS). Based on the IPCC (Guidelines for national greenhouse gas inventories. The intergovernmental panel on climate change, Institute for Global Environmental Strategies, Kanagawa, 2006. http://www.ipcc-nggip.iges.or.jp/support/Primer_2006GLs.pdf) methodologies, the annual GHG emissions considering a 6-year production cycle included agricultural sources and gasoline consumption related to the most important agricultural phases in the field, and a potential for soil carbon accumulation and biomass carbon fixation in all the studied scenarios. The lowest GHG emissions were estimated in PRP scenario (3684 kg CO2-eq ha−1 year−1), which also presented additional emissions because of soil carbon losses beyond the lower milk productivity. Highest GHG emissions were observed in IP scenario (7711 kg CO2-eq ha−1 year−1), which exhibited the highest milk productivity and a considerable potential for soil carbon accumulation that could help to offset its emissions. Nevertheless, SPS scenario, which had milk productivity close to that of IP, presented the highest potential to offset the total GHG emission (4878 kg CO2-eq ha−1 year−1) because of soil carbon accumulation and biomass carbon fixation in trees. This study contributed to indicate management strategies that should be prioritized to mitigate the main sources of GHG emission in the extensive and intensive dairy cattle production in the Andean region of Colombia. Department of Exact Sciences College of Agricultural and Veterinarian Sciences São Paulo State University FCAV/UNESP), Via de Acesso Prof. Paulo Donato Castellane s/n Department of Rural Development Centro do Ciências Agrárias Federal University of São Carlos (UFSCar), Rodovia Anhanguera, km 174 Brazilian Bioethanol Science and Technology Laboratory/Brazilian Center for Research in Energy and Materials (CTBE/CNPEM), Rua Giuseppe Máximo Scolfaro 10000, Polo II de Alta Tecnologia Department of Exact Sciences College of Agricultural and Veterinarian Sciences São Paulo State University FCAV/UNESP), Via de Acesso Prof. Paulo Donato Castellane s/n

El objetivo de esta investigación fue evaluar la cinética de degradación ruminal de los nutrientes in situ, así como la digestibilidad aparente de los nutrientes, población de protozoarios del rumen y producción de gas in vitro de dietas a base de biomasa poscosecha de Amaranthus cruentus. La biomasa pos-cosecha del A. cruentus con el forraje de Pennisetum clandestinum se mezcló en base seca de acuerdo a los siguientes tratamientos: T1: 100% A. cruentus, T2: 100% P. clandestinum, T3: 75% P. clandestinum + 25% A. cruentus, T4: 50% P. clandestinum + 50% A. cruentus, bajo un diseño completamente aleatorizado. Los parámetros de degradación ruminal muestran diferencias entre tratamientos (p, The aim of this research was to evaluate the in situ rumen degradation kinetics of nutrients, as well as the apparent digestibility of nutrients, population of rumen protozoa, and in vitro gas production of based diets from post-harvest biomass of Amaranthus cruentus. Post-harvest biomass of A. cruentus with Pennisetum clandestinum forage was mixed in dry basis according to four treatments: T1: 100% A. cruentus, T2: 100% P. clandestinum, T3: 75% P. clandestinum + 25% A. cruentus, T4: 50% P. clandestinum + 50% A. cruentus, under a completely randomized design. The ruminal degradation parameters showed differences between treatments (p

espanolEn el humedal El Burro ubicado en la ciudad de Bogota (Colombia), se describio la estructura y diversidad floristica de la zona terrestre, para el establecimiento de estrategias de restauracion ecologica. Utilizando un muestreo estratificado, se realizaron 15 parcelas de 200 m2 para plantas lenosas con DAP ≥ 1 cm y para herbaceas se siguio el metodo de cuadrante de 1 m2, con un total de 61 unidades de muestreo. Se identificaron las unidades de vegetacion de pastizal y vegetacion arborea y arbustiva mixta, en las cuales se registraron 51 especies incluidas en 45 generos y 30 familias. El pastizal se encuentra dominado por la especie introducida Pennisetum clandestinum, con presencia de individuos arbustivos y arboreos de Baccharis bogotensis, Acacia melanoxylon, Acacia decurrens y Salix humboldtiana, entre otras. La unidad de vegetacion arborea y arbustiva mixta se caracteriza por la presencia de las especies Caesalpinia spinosa, Cotoneaster pannosus, A. decurrens, A. melanoxylon y Pittosporum undulatum. La evaluacion de las condiciones actuales del ecosistema permitio evidenciar que aun cuando en las dos unidades de vegetacion se observa la presencia de especies vegetales nativas en estado de desarrollo juvenil, se deben implementar estrategias para superar la barrera que impone el pastizal con respecto al destino de las semillas y la sobrevivencia de plantulas, que permitan acelerar la regeneracion de estos ecosistemas. EnglishIn El Burro wetland, located in the city of Bogota (Colombia), the floristic structure and diversity of the terrestrial area were described for establishing ecological restoration strategies. Using a stratified sampling, fifteen 200 m2 plots for woody plants with DBH ≥ 1 cm and for herbaceous plants were made following the 1 m2 quadrant method with a total of 61 sample units. Vegetation grassland and tree and shrub vegetation mixed units were identified, from which 51 species included in 45 genera and 30 families were recorded. The pasture is dominated by the exotic Pennisetum clandestinum species, with the presence of shrubby and arboreal individuals of Baccharis bogotensis, Acacia melanoxylon, Acacia decurrens and Salix humboldtiana, among others. The arboreal vegetation and mixed tree and shrub unit is characterized by the presence of Caesalpinia spinosa, Cotoneaster pannosus, A. decurrens, A. melanoxylon and Pittosporum undulatum. The assessment of current conditions of the ecosystem showed that, even though in the two units of vegetation the presence of native plant species in juvenile development is observed, strategies must be implemented to overcome barrier imposed by the pasture with respect to the destination of seeds and seedling survival which allow accelerating the regeneration of these ecosystems.

The aim of this study was to determine the digestion of dry matter (MS), crude protein (PC) and amino acids (AA) in dairy cows. Two cannulated cows were used for the determination of passage rate (Kp), in situ ruminal degradability (DR) and intestinal digestibility (DI) by abomasal catheter. The data to calculate Kp was analyzed with NLIN procedure by SAS, and descriptive statistics for DR and DI of MS, PC and AA from Kikuyu grass (Pennisetum clandestinum), a commercial supplement and two sources of rumen-protected AA. The study showed a Kp and a ruminal retention time of 0.036 h-1 and 27.4 h. The highest values from DR of MS and CP were from Kikuyu grass (69.0 and 61.8%) and concentrate (84.7 and 77.2%), followed by MetP (60.2 and 66.7%) and LysP (6.72 and 11.4%). The highest percentages of rumen indegradable amino acids (AADR) were from Kikuyu and concentrate, varying between 58.7 and 68% in forage, and 76.1 and 82.9% in the concentrate. The DR was 11.5 and 65.8% in LysP and MetP, respectively. The DI of AA (%AADR) varied between 42.3 and 77.4% for Kikuyu and 42.2 and 59.3% for concentrate. The values for the protected amino acids were 42.1 for LysP and 58.6 for MetP. RESUMEN: El objetivo de este trabajo fue determinar la digestión de materia seca (MS), proteína cruda (PC) y aminoácidos (AA) en vacas lecheras. Fueron utilizadas dos vacas canuladas para la medición de la tasa de pasaje (Kp), la degradabilidad ruminal (DR) in situ y la digestibilidad intestinal (DI) por sonda abomasal. Los datos para calcular la Kp fueron analizados con el procedimiento NLIN de SAS, y mediante estadística descriptiva para la DR y DI de la MS, PC y AA del pasto kikuyo (Pennisetum clandestinum), un suplemento comercial y dos fuentes de AA protegidos (metionina protegida (MetP) y lisina protegida (LysP)). Se encontró una Kp y un tiempo medio de retención ruminal de 0,036 h-1 y 27,4 h. Los mayores valores de degradabilidad ruminal de la materia seca y proteína cruda, fueron para el kikuyo (69,0 y 61,8%) y el concentrado (84,7 y 77,2), seguido de MetP (60,2 y 66,7%) y LysP (6,72 y 11,4%). El mayor porcentaje de aminoácidos degradables en el rumen (AADR) fue mayor para el kikuyo y el concentrado, variando entre 58,7 y 68% para el forraje, y 76,1 y 82,9% para el concentrado. La DR de LysP y MetP fue de 11,5 y 65,8%, respectivamente. La digestibilidad intestinal de los aminoácidos (% AANDR) varió entre 42,3 y 77,4% para el kikuyo, y 42,2 y 59,3% para el concentrado. Los valores para los aminoácidos protegidos fueron de 42,1 en LysP y 58,6 para MetP.

The aim of this study was to evaluate the forage accumulation during the stocking period on Kikuyu grass pastures ( Pennisetum clandestinum Hochst. Ex. Chiov) subjected to intermittent stocking. Treatments consisted of four defoliation levels (removal of 40, 50, 60, and 70% relative to the initial height) starting from the same pre-grazing height (20 cm). The following variables were evaluated: leaf and stem elongation rates (evaluated during four times across the period of occupation), leaf area index, and forage accumulation rates. Additionally, ten tillers/strip were evaluated for the same variables into exclusion cages. The linear, quadratic and cubic effects of severity of defoliation were evaluated by orthogonal polynomials contrasts with 5% of significance level. There was a linear and inverse relationship between the proportion of removed leaf area index with leaf elongation and herbage accumulation rate. The leaf elongation rate in individual tillers and the forage accumulation rates of tillers on excluded areas from grazing were greater than those under grazing. During the stocking period on pastures submitted to intermittent grazing, forage accumulation was observed and it was linear and negatively correlated with the proportion of leaf area removed. Keywords: accumulation rate; forage production; leaf area index; severity of defoliation; tissue turnover.

Development of a soil quality index for kikuyu (Pennisetum clandestinum)–ryegrasss (Lolium spp.) pasture systems in the southern Cape of South Africa is important since there are certain warning signs that their sustainability is being threatened. A total of 142 pastures throughout the region were sampled and several soil physical, chemical and biological indicators were quantified. A minimum data set of the most sensitive indicators was chosen using principal component analyses. Linear scoring functions for these indicators were used to develop a soil quality index. The most sensitive indicators were: extractable P > gravel content > water holding capacity (WHC) > exchangeable acidity (EA) > soil organic matter (SOM) = penetration resistance (PR) > exchangeable Mn. The soil quality index (SQI) was equated as: SQI = 0.13 (PR) + 0.16 (Gravel) + 0.15 (WHC) + 0.14 (EA) + 0.17 (P) + 0.12 (Mn) + 0.13 (SOM). This soil quality index is appropriate for pasture systems in the southern Cape of South Africa, and may be useful for similar pasture systems in other areas.

Summary Five species of Sphenophorus were found in golf courses from 7 states of Mexico on various host plants; Sphenophorus arizonensis Horn from the state of Puebla on Paspalum vaginatum Swartz (new state and host record); Sphenophoruscicatristriatus Fahraeus was collected in Puebla on Cynodon dactylon (L.) Pers.; Sphenophorusincurrens Gyllenhal was collected in Queretaro on Pennisetum clandestinum Hochst, (new state record); Sphenophorus rectus (Say) was collected in Veracruz on P. clandestinum (new host plant record); and Sphenophorus venatus vestitus Chittenden was collected in Puebla, Veracruz, Guerrero, Baja California Sur and Nuevo Leon on C.dactylon and in Guanajuato on Lolium perenne L. (new host record). This information will aid in the development of improved management tactics for Sphenophorus species attacking turfgrass in Mexico.

El áfido Sipha flava (Hemiptera: Aphididae),se encontró en pasto kikuyo, Pennisetum clandestinum, en el norte de la Sabana de Bogotá y en el área urbana de Manizales. Se evaluó el daño ocasionado por su alimentación y las carac-terísticas de las colonias. El amarillamiento de la hoja pre-sentó un valor máximo de 31,3 %/m2. Las colonias de S. flava prefirieron el haz de la hoja y se ubicaron, mayormente, sobre la parte distal, donde se encontraron los síntomas. El máximo número de colonias por hoja fue de 17, las cuales, estaban constituidas por pocos individuos de adultos ápteros y ninfas. Los adultos alados no se observaron sobre el folla-je, pero se encontraron en trampas amarillas, ubicadas en zonas cercanas a los sitios de muestreo. Las poblaciones de S. flava, se encontraron en sitios con plena radiación solar y en hábitats donde el pasto crecía espontáneamente: bordes de cercas, vías, prados de jardines o canchas deportivas. No se encontró S. flava ni síntomas del daño en otras plantas asociadas al kikuyo. La infestación por S. flava puede afectar la calidad forrajera, por lo que el manejo de este insecto debe enfocarse en las prácticas culturales, empleo de los enemi-gos naturales en programas de control biólogo y en buscar fuentes de resistencia varietal. The aphid Sipha flava was found on kikuyu grass, Pennisetum clandestinum, in the Northern Sabana of Bogota and Manizales urban area. We evaluated the damage caused due to the aphid’s feeding habits and colonies characteristics. Symptoms of yellow leaves reached the maximum value of 31.3%/m2. Colonies of S. flava preferred the upper leaf feeding and were located in greater numbers on the distal part, where the symptoms were found. The maximum number of colonies found per leaf was 17 and they were composed by few individuals of apterous adults and nymphs. Alate adults were not found in the field but were found in yellowpantraps,located nearby to the field sample area. S. flava populations were found on kikuyu grass grown under full sun exposure and in habitats where this grass grows spontaneously, such as prairies, edges of roads, orchards, gardens, and sport fields. Neither S. flava nor the symptoms of its damage were present on other plants associated with kikuyu grass. The infestation by S. flava can affect the quality of forage and the management of this insect should focus on cultural practices, the use of natural enemies in biological control programs, and by searching for varietal resistance sources. Incluye referencias bibliográficas

Kikuyu (Pennisetum clandestinum)–ryegrass (Lolium spp.) cultivated pastures form the base for dairy production in the southern Cape region of South Africa. The impact of various methods and implements used to over-sow ryegrass on the productivity and botanical composition of the pasture is unknown. The study aimed to assess the impact of cultivation along a soil disturbance gradient on the productivity and botanical composition of kikuyu-based pastures. Five tillage treatments were assessed, namely kikuyu over-sown with ryegrass using a minimum till planter, eradication of kikuyu with herbicide and ryegrass sown with a minimum-till planter, shallow ( 150 mm) disturbance with a rotavator or conventional tillage, respectively, and a control. The autumn, spring, summer and annual productions of treatments with the least soil disturbance were the highest (P ≤ 0.05). Shallow or deep tillage resulted in intermediate annual productions and the lowest (P ≤ 0.05) was recorded for the herbicide t...

Pasture-based automatic milking systems (AMS) require cow traffic to enable cows to be milked. The interval between milkings can be manipulated by strategically allocating pasture. The current experiment investigated the effect of replacing an allocation of grazed pasture with grazed soybean (Glycine max) with the hypothesis that incorporating soybean would increase voluntary cow traffic and milk production. One hundred and eighty mixed age, primiparous and multiparous Holstein-Friesian/Illawarra cows were randomly assigned to two treatment groups (n = 90/group) with a 2×2 Latin square design. Each group was either offered treatments of kikuyu grass (Pennisetum clandestinum Hoach ex Chiov.) pasture (pasture) or soybean from 0900 h to 1500 h during the experimental period which consisted of 2 periods of 3 days following 5 days of training and adaptation in each period with groups crossing over treatments after the first period. The number of cows trafficking to each treatment was similar together with milk yield (mean ≈18 L/cow/d) in this experiment. For the cows that arrived at soybean or pasture there were significant differences in their behaviour and consequently the number of cows exiting each treatment paddock. There was greater cow traffic (more cows and sooner) exiting pasture allocations. Cows that arrived at soybean stayed on the allocation for 25% more time and ate more forage (8.5 kg/cow/d/allocation) relative to pasture (4.7 kg/cow/d/allocation). Pasture cows predominantly replaced eating time with rumination. These findings suggest that replacing pasture with alternative grazeable forages provides no additional incentive to increase voluntary cow traffic to an allocation of feed in AMS. This work highlights the opportunity to increase forage intakes in AMS through the incorporation of alternative forages.

El objetivo de este trabajo fue analizar el uso potencial de la Tithonia diversifolia (Hemsl.) A. Gray (botón de oro) en la alimentación de vacas lecheras en el trópico alto colombiano. Se eligieron términos clave para la búsqueda de información y a partir de ellos se abordaron y analizaron diferentes publicaciones, permitiendo un acercamiento a la problemática propuesta. En estos sistemas de producción típicos del trópico alto en Colombia, el kikuyo (Pennisetum clandestinum) contribuye con el mayor aporte en la ración del ganado y debido al alto N, la baja fibra y materia seca, lleva con frecuencia a balances energéticos negativos en las vacas más productivas, por lo que en muchos casos se sostiene la producción con alimento comercial, compuesto principalmente por cereales y con altos niveles de proteína. Las necesidades nutricionales de este tipo de sistemas productivos están orientados a encontrar estrategias que permitan mejorar la oferta forrajera, en términos de variedad y calidad, disminuir la dependencia de alimentos comerciales o al menos facilitar la inclusión de otros que mejoren el desempeño animal. A partir de este análisis, se evidencia el potencial de T. diversifolia en la alimentación de vacas lecheras de alta producción; esta forrajera arbustiva, por su contenido de proteína, carbohidratos solubles y taninos, puede tener un impacto positivo sobre los sistemas de ganadería lechera intensiva y puede incorporarse a suplementos alimenticios. The objective of this study was to analyze the potential use of Tithonia diversifolia (Hemsl.) A. Gray (Mexican sunflower) in dairy cattle feeding in the Colombian high tropics. Key terms were chosen to search for information and from them this we discussed and analyzed several publications, allowing an approach to the problem proposed. It is common that in the high-tropic dairy farms of Colombia the main component of the cattle’s diet is the Kikuyu grass (Pennisetum clandestinum). Given its characteristics of high levels of Nitrogen, low levels of fiber and dry matter, it is common that this diet causes a negative energetic balance in the most productive cows. In order to sustain production in those cases, sometimes it is required to supplement the forage with commercial rations, which have high protein levels, and are mainly composed by cereals. The nutritional requirements of these production systems demand strategies that allow the improvement and quality of fodder offer, and to reduce the dependence on commercial rations or at least to ease the inclusion of others that improve animal performance. From this analysis, the benefits and potential use of T. diversifolia in feeding high producing dairy cows were recognized. Considering the content of protein, soluble carbohydrates and tannins, the forage of this shrub may have a positive impact on intensive dairy farming systems and could have potential to be incorporated into dietary supplements.

Some factors affecting yield of pastures grown in a water harvesting project on a solodic soil were investigated at Lawes in south eastern Queensland. In view of the low and erratic rainfall (30 inches per annum) and the low nitrogen status of the soil, experiments were designed to assess the relative importance of these limitations. Eight levels of ammonium sulphate (O to 48 cwt per acre) were applied to green panic (Panicum maximum var trichoglume K.Schum. Eyles) grown under natural rainfall and under irrigation for one year. Without ammonium sulphate, control plots produced 0.97 tons dry matter per acre, while irrigated plots produced 1.16 tons per acre. Highest yields were produced with 32 cwt per acre of ammonium sulphate, and, on these plots, yields for natural rainfall and irrigation were 7.3 and 8.3 tons per acre respectively. Green panic failed to persist except at high levels of ammonium sulphate, and was displaced by rhodes grass (Chloris gayana Kunth). Four levels of water and nitrogen were applied to kikuyu (Pennisetum clandestinum Hochst.) in spring, and produced essentially the same result - a marked response to nitrogen and a small response to water. There were no water-nitrogen interactions in either experiment. Thus, on this soil type at Lawes, nitrogen deficiency limits grass yield to a much greater extent than low rainfall. In both experiments, nitrogen greatly increased water use efficiency, while irrigation had the opposite effect. Nitrogen was most efficient in promoting growth when applied at rates of 200 to 400 lb per acre when extra yields of 30 to 40 lb dry matter per lb nitrogen were obtained. Rhodes and green panic grew rigorously over the period November to March, while kikuyu appeared to make more growth in autumn and spring. Green panic and kikuyu were grown in adjacent areas with ample water and nitrogen over a period of one year. Dry matter production from kikuyu exceeded a rate of 60 lb per day for 33 weeks, while the corresponding period for green panic was 18 weeks. On plots cut each 6 weeks, kikuyu produced 25,800 lb dry matter per acre, while green panic produced 14,900 lb per acre. At Lawes, dry spells of 12 days or more are likely to occur in every month of the year. In a field experiment, dry spells of 14 days reduced yield of siratro (Phaseolus atropurpureus D.C.) by one half compared with plots subjected to dry spells of 7 days. Nedulation and nitrogen production in tops were similarly affected. Thus, for the species tested, the response to irrigation was much greater with the legume than with grasses. The productivity of a number of pasture mixtures was compared under irrigation with an ample supply of nutrients. Farmyard manure was added to plots of temperate species to aid establishment. Rhodes grass was used as the companion species for each of the following legumes : lucerne (Medicago sativa L.), white clover (Trifolium repens L.), subterranean clover (T.subterraneum L.), siratro, and four cultivars of glycine (Glycine javanica L.). Over the two years of the experiment, lucerne plots were the most productive in terms of dry matter yield and nitrogen production in tops. In the second season, dry matter yields of grass and legume in lucerne, siratro, and glycine (CPI 23411) plots were 2.96, 2.42, and 2.43 tons per acre, while nitrogen yields in tops were 177, 144, and 144 lb per acre respectively. However, glycine failed to persist, and production from glycine and siratro was limited to the period November to April inclusive, while lucerne continued to grow through winter at the rate of 11 lb per acre per day. Following a severe drought in 1964-65, lucerne and siratro showed excellent persistence, while the other legumes were virtually eliminated. Lucerne and kikuyu emerged as the species showing greatest potential for use in water harvesting schemes, and pastures of kikuyu, rhodes and lucerne, and rhodes and siratro were shown to compare favourably in dry matter production with pastures grown in water harvesting situations elsewhere.

Winery wastewater often contains elevated concentrations of sodium (Na), and has a high chemical oxygen demand (COD). In constructed wetlands, Na may be removed through phytoremediation by such macrophytic plants as Typha latifolia, Juncus acutus and Scirpus maritimus. The relative abilities of these plants to absorb Na, and to tolerate high COD wastewaters was determined in a glasshouse pot trial. Also tested were Pennisetum clandestinum (Kikuyu) and Vetiveria zizanioides (Vetiver) grass, which are used on wastewater disposal sites. Treatments consisted of factorial combinations of Na and COD. Toxicity symptoms were not apparent below 16.2 μM Na/L < 5 000 mg COD L, but were marked at ≥ 40 μM Na/L and ≥ 15 000 mg COD/L. Of the macrophytes, J. acutus was the least affected by high Na and COD levels. Averaged across the Na and COD treatments, total plant dry mass (DM) in the macrophytes peaked at 40 μM Na/L, as did ability to tolerate COD. The total Na in the top growth was greatest in J. acutus from which 61.4 mg Na/plant (767 mg/m2) could potentially be harvested after six months. Equivalent figures for T. latifolia and S. maritimus were 38.8 and 25.0 g/plant, respectively. Of the grasses, P. clandestinum produced 35% more total DM than V. zizanioides. Top-growth Na contents were, respectively, 1427 and 29.1 mg/ plant. To maximise Na uptake in harvestable plant components, J. acutus should be planted in wetlands, and P. clandestinum in pastures used for wastewater disposal.

Nitrogen (N) fertiliser is applied to perennial horticultural crops to increase yields, but subsequent N losses in subtropical plantations may be high due to intense rainfall and warmer temperatures. While legume cover crops could potentially contribute N to the tree crops and reduce fertiliser-N requirements, few studies have quantified potential fixed-N inputs from cover crops legumes in tropical or subtropical tree crop systems. To address this, we investigated growth and N fixation of summer-growing Pinto peanut (Arachis pintoi Krapov. & W. C. Greg cv. Amarillo) and winter/spring dominant white clover (Trifolium repens L. cv. Haifa) grown as a mixed species cover crop in two commercial subtropical avocado (Persea americana Mill. cv. Hass) plantations. Legume biomass was assessed prior to mowing of the inter-row (fortnightly in summer and every 6⁻8 weeks over winter) and N fixation was estimated using the 15N natural abundance technique. Biomass production was 7377 kg ha−1 (930 kg ha−1 for white clover and 6447 kg ha−1 for Pinto peanut) at the first site over the 14-month period from December 2014 to January 2016, and 4467 kg ha−1 (1114 kg ha−1 for white clover and 3353 kg ha−1 for Pinto peanut) at the second site over the same period. Estimation of N fixation was not possible at the first site, due to a lack of difference in isotopic discrimination between the legume shoots and the reference plant (kikuyu (Pennisetum clandestinum Chiov.)) material. While legume shoots accumulated 157 kg N ha−1 (38 kg ha−1 for white clover and 119 kg ha−1 for Pinto peanut) across the season at site 1, the % N derived from atmosphere (%Ndfa) in legumes was relatively low (50⁻60% in Pinto peanut during the warmer months and around 30% in autumn and early spring, and from 13 % in April to 69% in September for white clover). The low %Ndfa in the legumes may have been due to low rainfall or molybdenum (Mo) deficiency. Ultimately the legume cover crops contributed an estimated 50 kg fixed N ha−1, which could partially offset fertiliser N requirements of the tree crop. Our results demonstrate the need to quantify N fixation in legume cover crops to assess potential N benefits as opposed to relying on typical measurements of legume biomass and N accumulation.

The volcanic cones of Auckland are distinctive landmarks of that city, currently realized as an ‘archipelago’ of grassy reserved hills. Most of these cones were modified as hill forts during former occupation by Māori. Here, we review the Auckland volcanic reserve network and survey the current groundcover vegetation and soils of four large representative examples. Forty-eight reserves currently occur on remnant volcanic features. As well as two inshore island reserves (2372 ha), the other 46 reserves total 1241 ha. Most of the volcanic reserves support exotic grassland with rare forest patches. Groundcover vegetation follows a topographic sequence from flatter, fertile sites dominated by Lolium perenne, Trifolium repens and Pennisetum clandestinum, to moderately steep sites dominated by a diverse range of exotic grasses, to steep, lower fertility sites dominated by Microlaena stipoides. Pennisetum clandestinum is a major component of groundcover vegetation on many sites across all slope classes, its abun...

Global attention on biofuels and the potential for Jatropha curcas to produce biodiesel from marginal land with low inputs has recently created world-wide interest in this species. This paper reports on the water dynamics and productivity of J. curcas in a silvopastoral experiment with Pennisetum clandestinum at the Ukulinga research farm of the University of KwaZulu-Natal near Pietermaritzburg, South Africa. Measurements of daily total evaporation rates during December – February (summer) on clear hot days ranged between 3 and 4 mm d−1. However, due to the deciduous nature of the species, water use was negligible (

L’efficacite du metabolisme azote et energetique pour repondre aux besoins des ruminants a haut niveau de production depend de la digestion microbienne du rumen. Celle-ci pourrait etre amelioree par l’utilisation des huiles essentielles (HE). L’objectif de ce travail est donc de contribuer a l’amelioration des connaissances sur la valorisation des huiles essentielles (HE) dans l’alimentation des ruminants. Cet essai portant sur l’effet de l’huile essentielle (HE) des rhizomes de Zingiber officinale sur les parametres de digestibilite in vitro du foin de Pennisetum clandestinum a ete mene au Laboratoire de Production et Nutrition Animales (LAPRONAN), de l’Universite de Dschang. L’huile essentielle a ete extraite des rhizomes de Zingiber officinale par La technique d’hydrodistillation. La ration etait constituee de Pennisetum clandestinum (70%) et Bidens pilosa (30%). Trois doses (0, 40 et 80 μl) de l’huile essentielle ont ete utilisees lors de l’incubation des differentes rations. Les resultats de cette etude ont montre que l’ajout de 40 ou 80 μl d’huiles essentielles n’a eu aucun effet significatif sur le volume de gaz produit (GP) apres 24 h d’incubation, l’energie metabolisable (EM), la production d’acide gras volatils (AGV) et la digestibilite de la matiere organique (DIVMO). Par contre, la digestibilite de la matiere seche (DIVMS), la masse microbienne (MM) et l’azote residuel (NDF-N) ont significativement (p˂0,05) baisse avec le niveau croissant d’incorporation d’huile essentielle. La quantite de matiere organique fermentee pour produire 1ml de gaz (FC) des rations contenant 40 (4,4 mg/ml) ou 80 μl (4,41 mg/ml) d’huiles essentielles a ete comparable (P˃0,05) mais significativement (P˂0,05) plus eleves que celle de la ration sans huile essentielle (2,44 mg/ml). De maniere generale, l’incorporation de l’huile essentielle de Zingiber officinale dans la ration n’a pas ameliore les parametres de digestibilite chez les moutons. © 2018 International Formulae Group. All rights reserved. Mots cles: Digestibilite in vitro , huile essentielle, Pennisetum clandestinum , Zingiber officinale English Title: Effects of essential oil rhizomes of Zingiber officinale on the in vitro digestibility of the hay of Pennisetum clandestinum English Abstract The efficiency of metabolic nitrogen and energy for better ruminant’s production depends ruminal microbial digestion which could be improved by the use of the essential oil. This study aimed at improving the knowledge on the valorization of the essential oil within the ruminant’s feeding. Thus, the study of the effects of essential oil (EO) of Zingiber officinale on the in vitro digestibility parameters of the Pennisetum clandestinum hay was conducted in the Laboratory of the Livestock Productions, Animal Nutrition and feeding of the University of Dschang. Essential oil was extracted from the rhizomes of Zingiber officinale by hydrodistillation technique. The ration consisted of Pennisetum clandestinum (70%) and Bidens pilosa (30%) associated with three doses (0, 40 and 80 μl) of essential oil of Zingiber officinale with sheep ruminal fluid. The results showed that the addition of 40 or 80 μl of essential oils did not have any significant effect on production of gases (PG) after 24 h of incubation, metabolized energy, the volatile fatty acid production and the in vitro digestibility of the organic matter. On the other hand, the in vitro digestibility of the dry matter, microbial mass and residual nitrogen decreased significantly (p˂0.05) with the increasing level of essential oil. The organic matter fermented for the production of 1 ml gas (partitioning factor) of rations containing 40 (4.4 mg/ml) or 80 μl (4.41 mg/ml) essential oils was comparable (P˃0.05) but, significantly (P˂0.05) higher than that of the ration without essential oil (2.44 mg/ml). Generally, the incorporation of essential oils in the ration did not improved digestibility parameters at the sheep. © 2018 International Formulae Group. All rights reserved. Keywords: In vitro digestibility, essential oil, Pennisetum clandestinum , Zingiber officinale

Pennisetum longistylum, recently stated to be an older name for the well-known P. clandestinum (Cenchrus clandestinus), is shown to be a hybrid between P. clandestinum and P. villosum (C. longisetus). This is a rare hybrid only known from a few gatherings from the highlands of Ethiopia and Eritrea, the most recent one made in 1916. The new combination Cenchrus ×longistylus is proposed, and the names P. clandestinum and P. villosum are lectotypified.

a b s t r a c t High concentrations of sodium are toxic to most plant species, making soil salinity a major abiotic stress for plant productivity world-wide. Its salinity resistance makes the turf grass Pennisetum clandestinum Hochst (kikuyu grass) a candidate plant for utilization and reclamation of salinized areas. Kikuyu grass, a perennial native to the highlands of Central Africa now common in many areas, has recently become a valuable pasture and lawn plant because of its growth rate and well developed root system. However, its salt resistance has yet to be fully evaluated. The objective of this study was to identify the biochemical and physiological basis of salt resistance of kikuyu grass for the use of this grass as pasture, in phytoreme- diation, in controlling soil erosion and in biomass production for energy, in salt affected lands, where the growth of other species is markedly reduced. This study focused on the effect of salinity on germination, growth, metabolism, biochemistry, nutritive properties and root morphology of kikuyu grass. We com- pile evidence that kikuyu grass can germinate and grow in salinized areas. The use of this salt-tolerant grass may be an important part of a range of practices, such as recycling saline wastewater and reclaiming salt-affected soil in arid-zone irrigation districts. © 2012 Elsevier B.V. All rights reserved.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:29:29Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:32:33Z : No. of bitstreams: 1 2-s2.0-84877288649.pdf: 877019 bytes, checksum: 87b02224b512e029dd59cd1d1fa4c396 (MD5) Made available in DSpace on 2014-05-27T11:29:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-05-13 We studied the efficacy of infective juveniles (IJ) of Steinernema sp. strain JCL024 and Heterorhabditis sp. strain SL0708 on adults and nymphs of Collaria scenica under greenhouse conditions. Five doses were evaluated (2, 16, 78, 160 IJ) cm-2 leaf) for each nematode. The experiment was evaluated for 21 days every 24 hours, making mortality counts and assessment of damage on Kikuyo grass. The bugs showed 100% mortality after 15 days. Each bug produced an average of 13,000 IJ/6 days. As for the damage did not reach level 2 within 21 days prior to treatment without nematodes that damage introduced 3 with necrosis and apical leaf curl. Thus, Steinernema sp. strain JCL024 and Heterorhabditis sp. strain SL0708 exercised control bug on the grass and kept under the level of damage to the foliage. Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal Departamento de Fitossanidade, Via de Acesso Prof. Paulo Donato Castelane, Rural, CEP 14884-900, Jaboticabal-SP Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Ciências Agronômicas de Botucatu Departamento de Horticultura, Rua Jose Barbosa de Barros, 1780, CEP 18610-307, Botucatu-SP Pontificia Universidad Javeriana Facultad de Ciencias Departamento de Biología, Carrera 7 No 43-82, Edificio 54, Oficina 200, Bogotá DC Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal Departamento de Fitossanidade, Via de Acesso Prof. Paulo Donato Castelane, Rural, CEP 14884-900, Jaboticabal-SP Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Ciências Agronômicas de Botucatu Departamento de Horticultura, Rua Jose Barbosa de Barros, 1780, CEP 18610-307, Botucatu-SP

Forages cover extensive areas of agricultural land in Australia, but only limited data is available on the potential of these different forages to sequester soil organic carbon (SOC) under best practice management. This study was undertaken on a brown dermosol in the warm temperate climate of Camden, Australia, over three years, to evaluate a range of perennial and annual forages for their impact on SOC and soil nitrogen (N). The C4 perennial forages kikuyu (Pennisetum clandestinum Hochst. ex. Chivov.) and paspalum (Paspalum dilatatum Poir.) increased (P 0.05). The high productivity of legumes led to high mean estimate of N fixation of up to 726 kg N ha/year over the three years. However, as most of the legume shoot production of the forage species was removed there, was a negligible increase in soil N levels. This study has shown that the choice of forage has a large impact on the amount of carbon that can be sequestered into the soil.

Pennisetum clandestinum (kikuyo) es una pastura común en los sistemas silvopastoriles del altiplano cundiboyacense, con altas propiedades nutritivas. Por tanto estudios que permitan mejorar el proceso de producción en términos económicos y ambientales reviste gran importancia. En este estudio se evaluó el papel de la inoculación con bacterias promotoras de crecimiento vegetal (PGPR) sobre el crecimiento de pasto kikuyo. Las cepas 4K y 5B fueron identificadas mediante amplificación y análisis del 16S rADN, como Stenotrophomona ssp. y Pseudomona ssp., respectivamente, caracterizadas por su eficiencia in vitro en la fijación biológica de nitrógeno, producción de compuestos indólicos y solubilización de fosfatos. Se evaluaron las cepas en condiciones de invernadero en tres tiempos de crecimiento de la planta (70, 100 y 130 días). Se evidenció que la cepa 4K incrementó el peso seco radicular de la planta en 50% a los 70 y 100 días, mientras que la cepa 5B mostró un comportamiento similar en el peso seco aéreo y radicular con aumentos de hasta el 50% a los 130 d. El efecto más importante se presentó después de 100 d donde los tratamientos TQ, TB1 y TB2, superaron en más del 80% al testigo absoluto en el peso fresco de la parte aérea. Estos resultados demostraron que la inoculación de PGPR representa una alternativa biotecnológica para promover el crecimiento de P. clandestinum, con efectos relevantes en producción de biomasa 100 días después de la siembra (dds).

Molecular evidence from sequences of three regions of ribosomal DNA (partial SSU, ITS-1, 5.8S and ITS-2, and D2/D3 expansion segments of LSU) is presented to show that the two belonolaimids described from turfgrass in Australia (Ibipora lolii and Morulaimus gigas) are identical. Morulaimus gigas is therefore considered a junior synonym of I. lolii. The decision to place the nematode in Ibipora rather than Morulaimus is supported by molecular studies which showed that I. lolii is not closely related to Morulaimus or Carphodorus, two belonolaimid genera that are only found in Australia. Survey data are presented to show that I. lolii is widespread on turfgrass around Newcastle in New South Wales and in Perth, Western Australia, where the infested area is increasing rapidly, largely because the nematode is being spread in planting material. Ibipora lolii damages all turfgrass species but is particularly damaging to kikuyu grass (Pennisetum clandestinum), the main grass used for sporting fields and recreational areas in warm regions of Australia. Data from an experiment in pots also show that the nematode multiplies to damaging levels on sugarcane. Symptoms on grasses are similar to those caused by the sting nematode, Belonolaimus longicaudatus, in south-eastern USA, but because the two nematodes are taxonomically different, I. lolii is referred to as the southern sting nematode. Ibipora lolii was not found in surveys of natural vegetation on the east and west coasts of Australia, suggesting that it is an introduced species, possibly originating in South America or the Caribbean, where other Ibipora species are found.

In Mediterranean areas, very scarce rainfalls during the summer season are a limiting factor to the sowing and managing of turfgrasses. This work evaluates the response to different irrigation regimes (50 or 75% of reference evapotranspiration) of Cynodon dactylon (L.) Pers. cv Transcontinental , Paspalum vaginatum Swartz cv Salam , Pennisetum clandestinum (Chiov.) Hochst. cv AZ1 , Stenotaphrum secundatum (Walt.) Kuntze cv Palmetto and Zoysia japonica Steud. cv El Toro . Performance of turfgrasses was evaluated in term of turf quality, colour index and ground cover. Only when rainfalls were scarce, water regime restoring the 75% of the evapotranspiration (ET o ) showed significant effects. Under rainy conditions, the restoration of only the 50% of ET o was able to give highly acceptable values. The best performance was observed for Z. japonica , C. dactylon and P. vaginatum , whereas P. clandestinum and S. secundatum showed lower adaptability to water stress.

Esta investigación tuvo como objetivo el aislamiento y caracterización de bacterias con potencial para promover el crecimiento del pasto Pennisetum clandestinum en suelos salinos simulados. De muestras de suelo rizosférico de P. clandestinum se aislaron 92 bacterias Gram positivas, diez aislados crecieron en agar nutritivo suplementado con NaCl (2,578 M). Los aislados se evaluaron bajo condiciones de invernadero; las cepas identificadas como KISA 34 y KISA 71 fueron seleccionadas como las mejores con base a la prueba estadística de Dunnet (p≤ 0,05) y fueron identificadas molecularmente como Bacillus amyloliquefaciens KISA 34 y Bacillus subtilis KISA 71. Estas cepas tienen la capacidad de producir; amonio, exopolisacáridos y celulosa, y tanto en presencia como ausencia de NaCl, produjeron índoles totales y solubilización de fósforo. La evaluación de las cepas en invernadero evidenció que el T6 - KISA 34 + KISA 71+ 25 % (Roca Fosfórica RF) con respecto al T2- testigo químico completo incrementaron de manera significativa la biomasa y el desarrollo de la planta (p≤ 0.05). Los resultados de esta investigación demostraron que las cepas aisladas tienen la capacidad de crecer en suelos salinos conservando sus características como promotoras de crecimiento vegetal con efectos positivos sobre P. clandestinum. This research aims the isolation and characterization of bacteria with potential to promote the growth of grass Pennisetumclandestinum in simulated saline soils. 92 Gram positive bacterias were isolated from Rhizosphere soil samples of P. clandestinum. Ten isolated bacteria grew on nutrient agar supplemented with NaCl (2.578 M). Isolates were evaluated under greenhouse conditions; the strains identified as KISA 34 and KISA 71 were selected as the best based on the statistical test of Dunnet (p ≤ 0.05) and were identified Bacillus amyloliquefaciens KISA 34 and Bacillus subtilis KISA 71. These strains have the ability to produce ammonium, exopolysaccharides and cellulose, both in absence and presence of NaCl. The strains produced indoles and phosphorus solubilization. The evaluation of strains in greenhouse showed that the T6 - KISA 34 + KISA 71+ 25 % (phosphate rock RF) significantly increased biomass and plant development (p≤ 0.05) compared with T2 - full fertilization . The results of this research showed that isolates have the ability to grow in saline soils retaining its characteristics as promoting plant growth with positive effects on P. clandestinum.Key words: Bacillus subtilis, Bacillus amyloliquefaciens, biofertilizer, salinity, phosphorus solubilization.

Suitability of the Natural Resources Conservation Service (NRCS) curve number (CN) model of run-off prediction was evaluated on three humid tropical forested catchments in Kimakia, Kenya. The catchments were dominated by Pinus patula (catchment A), Arundinaria alpina (catchment C) and Pennisetum clandestinum (catchment M). The study used discharge and rainfall data collected between 1958 and 1986. Seventy-three (73) isolated storms were graphically separated into baseflow, interflow and surface run-off. Forest cover types significantly improved catchments characteristics that influence baseflow and interflow generation in catchment C but not those that influence surface run-off production. In its original form, the NRCS CN model resulted in direct run-off estimates that deviated from observed ones by between 43.8% and 55.3%. These discrepancies were minimized through modification of the β and CN parameters. CN generated empirically using storm rainfall predicted the direct run-off satisfactorily. Therefore, the modified NRCS CN model adequately estimates direct run-off from humid tropical forested catchments.

Widden Brook in the Hunter Valley, Australia, was first settled by Europeans in 1831 and had widened substantially by the 1870s due to frequent floods during a flood-dominated regime impacting on highly disturbed banks whose riparian trees had been either ringbarked or cleared, and whose understorey had been grazed. Catastrophic floods in 1950 (many), two in August 1952 and one in February 1955 effected the final phase of channel widening at the onset of a second flood-dominated regime more than half a century after the initial widening. Contraction has been active since 1963 by a combination of five biogeomorphic processes. Firstly, rapid channel widening, migration and cutoffs totally reworked the pre-European floodplain and were followed by active floodplain formation. Initial bar formation was replaced by sand splay and overbank deposition which constructed a new floodplain and narrower channel. Secondly, overwidened channel segments that were produced by the catastrophic 1955 flood have contracted since 1963 by the formation of up to four bank-attached, discontinuous benches below the floodplain. Each bench has a bar nucleus of pebbly coarse sand overlain by stratified fine-medium sand and mud. Colonisation by River Sheoaks (Casuarina cunninghamiana subsp. cunninghamiana) or grasses (Cynodon dactylon, Paspalum distichum, Pennisetum clandestinum) is important in converting bars to benches. Thirdly, narrower segments which developed since 1963 have contracted by small-scale accretion on both banks. These deposits are steeply dipping, interbedded sand and mud trapped by stoloniferous and rhizomatous grasses (C. dactylon, P. distichum, P. clandestinum) which also rapidly stabilise the deposits. Fourthly, rare laterally migrating, small radius bends have contracted by recent point bar formation greatly exceeding cutbank recession rates. Point bar formation is controlled by secondary currents producing inclined stratified coarse sands without the influence of vegetation. Lastly, rare, overwidened, non-migrating, large radius bends have greatly contracted by the infilling of dissecting chutes across the convex bank. Establishment of stoloniferous and rhizomatous clonal grasses (Phragmites australis, C. dactylon, P. distichum, P. clandestinum) is important in inducing sedimentation of the chutes. Contraction has produced a much narrower channel than the design width between river training fences which were installed progressively between the 1960s and 1990s. The recent flood history of Widden Brook has not included any catastrophic floods of a size similar to February 1955. Our work demonstrates that both trees and grasses can be associated with narrower channel widths and that the causal link between width and vegetation type is more complex than usually acknowledged.

Two new species of ectotrophic root-infecting fungi pathogenic to warm-season turfgrasses are described. Magnaporthe garrettii P. T. W. Wong & M. L. Dickinson sp. nov. causes a serious patch disease on couch (Cynodon dactylon) bowling greens in South Australia, and Magnaporthe griffinii P. T. W. Wong & A.M. Stirling sp. nov. is associated with a disease complex (“summer decline”) of hybrid couch (C. dactylon × C. transvaalensis) golf greens in New South Wales and Queensland. Both are homothallic, producing perithecia readily on potato dextrose agar. They differ from other Magnaporthe spp. in having uniseriate rather than biseriate or multiseriate ascospores, and the absence of a conidial anamorph. Analysis of nuclear rRNA ITS sequences has shown that M. griffinii is a new taxon with low homology to M. grisea, M. poae, M. rhizophila, M. salvinii and Gaeumannomyces graminis. This could not be carried out with M. garrettii because there were no living cultures available and the genomic DNA extracted from dead mycelia and perithecia was totally degraded. However, the two new species can be readily distinguished by morphological differences in their perithecia and ascospores. Examination of earlier herbarium specimens has shown that M. garrettii was associated with a patch disease of buffalo grass (Stenotaphrum secundatum) in New South Wales and M. griffinii was associated with diseases of South African couch grass (C. tranvaalensis) in South Australia and of kikuyu grass (Pennisetum clandestinum) in New South Wales.

Conservation agriculture (CA) is rapidly developing in Madagascar but little is known about its effects on local soil functioning. To assess some of those effects, we investigated the effects of three CA systems and two levels of fertilization on soil functioning using nematofauna as indicator. The systems consisted in (i) soybean ( Glycine max L.)-maize ( Zea mays L.) rotation with mulch of residues, CA-R; (ii) bean ( Phaseolus vulgaris L.)-soybean rotation with living mulch of Pennisetum clandestinum , CA-K; (iii) continuous maize with living mulch of Desmodium uncinatum , CA-D and were compared with soybean–maize under conventional tillage (CT) and natural fallow (NF). The fertilization levels consisted in (i) farmyard manure, FYM; and (ii) farmyard manure + mineral fertilizers, FYM + NPK. Located in the Highlands of Madagascar, the experiment was setup in 1991 and andic Dystrustept soil had been sampled in 2005–2007. We measured nematode abundances and ecological indices as well as the abundance and biomass of soil macrofauna, soil water and organic C and N contents and plant yields. We hypothesized that (1) CA including maize in monoculture would lead to higher abundance of plant-parasitic nematodes; (2) both dead-residue mulch and inorganic fertilization would lead to a more basal nematode community structure; and (3) that the combination of system effects on soil nematode community would be able to forecast differential crop yields for the CA systems. Our results show that CA systems tested were able to support better/comparable maize and soybean yields compared with CT, provided that crop rotation is correctly managed. Supporting our first hypothesis, abundance of plant parasitic nematodes was (40–150 times) higher under maize monoculture. Abundance of soil nematofauna and trophic groups (excepted carnivores and omnivores) was stable during the three years. Inorganic fertilization increases carnivorous and omnivorous nematodes to 122% and 140%, respectively. Ecological indices showed that soil functioning of CA systems was intermediate between that NF and CT. CA systems were characterized by a highly structured soil food-web compared with CT. Yet, soil processes intensity revealed to be lower in CA with dead mulch compared with CA with living mulch, contrasting with our second hypothesis. The characterization of nematofauna discriminated well the different systems and supports our third hypothesis. Nematode structure and enrichment indices were significantly correlated to soil organic C and N content as well as grain yields. They proved to be powerful bio-indicators of soil functioning in the CA systems studied.

Water conservation strategies are being developed in regions of the world expected to experience decreases in water resources due to changing climates. Strategies advocated for improving water-use efficiency may increase the incidence of soil water repellency in sandy-textured soils. We evaluated the effect of soil wetting agent formulation, and application frequency, on water repellency in sandy soil with two contrasting organic matter (OM) contents under kikuyugrass [Pennisetum clandestinum (Holst. Ex Chiov)], and irrigated at 60% replacement of net evaporation in a climate subject to hot, dry summers. The randomized plot design included two turfgrass ages [established from 20 week (7.7% OM) or 20 year old (30% OM) turfgrass in 2005, the latter included a 50 mm ‘mat’ layer], two soil wetting agent formulations (granular or liquid); two application frequencies (one or two applications per irrigation season); and plots of both turfgrass ages that did not receive any wetting agent (nil control). Both wetting agent formulations contained the same active ingredient (propylene oxide–ethylene oxide block polymer), and all wetting agent treatments received the same rate (69 L active ingredient ha−1). Water repellency in the surface soil (0–5 mm), measured using the molarity of ethanol droplet test (MED), ranged from 1.09 M to 4.32 M during the irrigation season, and was more severe in the soil with high OM (average MED, 3.3 M) than low OM content (average MED, 2.7 M). Applying one application of either granular or liquid soil wetting agent at the commencement of the irrigation season decreased the severity of soil water repellency by up to 30% in the high OM soil and by up to 60% in the low OM soil during the summer, and without the need for a second application. The decline in soil water repellency in response to soil wetting agent application was not matched by an increase in soil VWC in summer, and turfgrass quality was considered acceptable throughout the study. The soil wetting agents were less effective at treating water repellent sand containing a significant amount of OM than sand with low OM content.

We investigated the type and extent of degradation at three sites on the Agulhas Plain, South Africa: an old field dominated by the alien grass Pennisetum clandestinum Pers. (kikuyu), an abandoned Eucalyptus plantation, and a natural fynbos community invaded by nitrogen fixing-Australian Acacia species. These forms of degradation are representative of many areas in the region. By identifying the nature and degree of ecosystem degradation we aimed to determine appropriate strategies for restoration in this biodiversity hotspot. Vegetation surveys were conducted at degraded sites and carefully selected reference sites. Soil-stored propagule seed banks and macro- and micro-soil nutrients were determined. Species richness, diversity and native cover under Eucalyptus were extremely low compared to the reference site and alterations of the soil nutrients were the most severe. The cover of indigenous species under Acacia did not differ significantly from that in reference sites, but species richness was lower under Acacia and soils were considerably enriched. Native species richness was much lower in the kikuyu site, but soil nutrient status was similar to the reference site. Removal of the alien species alone may be sufficient to re-initiate ecosystem recovery at the kikuyu site, whereas active restoration is required to restore functioning ecosystems dominated by native species in the Acacia thicket and the Eucalyptus plantation. To restore native plant communities we suggest burning, mulching with sawdust and sowing of native species.

The effectiveness of four granular wetting agents to decrease water repellency in sandy soils of contrasting organic matter (OM) content and influences on kikuyugrass [Pennisetum clandestinum (Holst. Ex Chiov)] grown as turfgrass, were evaluated. A laboratory test assessed the wettability of two non-wetting soils (low OM, 4.7%; high OM, 17%) after treatment with granular soil wetting agents, with four being selected for field experimentation. A field experiment included two turfgrass ages (established from 20 week or 20 year old turfgrass in 2005; the latter included a 50 mm ‘mat’ layer and thus had high OM content in the surface soil), four granular soil wetting agents (plus a ‘nil’ as control), and five replicates. Surface soil (0–25 mm) water repellency, measured using the molarity of ethanol droplet test (MED), ranged from 0.4 M to 4.3 M during the irrigation season, and repellency was more severe in the soil with high OM (32%) content than low OM (8.6%) content. Soil wetting agents decreased the development of soil water repellency to varying extents, and maintained turfgrass quality; with improvement related to the amount of active ingredient applied. We recommend utilising an effective soil wetting agent, in combination with practices that limit the accumulation of soil OM, to decrease the severity and incidence of soil water repellency in turfgrass grown on sandy soils.