Search

ilustraciones, graficas La co-inoculación con bacterias solubilizadoras de fósforo (PGPB) en asocio con fuentes de fósforo (P) puede mejorar la disponibilidad de P en el suelo, generando sistemas de cultivos más sostenibles, eficientes en el aprovechamiento de nutrientes y de mayor productividad. La implementación de estas tecnologías en gramíneas de pastoreo como el kikuyo establecidas sobre suelos Andisoles con alta retención fosfórica ha sido poco explorada. El objetivo de esta investigación fue evaluar la respuesta productiva del pasto kikuyo y la dinámica del P en el suelo a la co-inoculación de PGPB con diferentes fuentes de P. El experimento se estableció sobre una pradera de kikuyo durante 18 meses, utilizando fuentes de P: alta solubilidad (fosfato diamónico-DAP), baja solubilidad (roca fosfórica-RF) y (compost-MO); y la co-inoculación de tres BSF (Herbaspirillum sp. AP21, Azospirillum brasilense D7, Rhizobium leguminosarum T88). Se encontró que la co-inoculación con BSF mejoró en 20% la disponibilidad de P en el suelo con una mayor actividad enzimática (64%), incrementando la productividad del kikuyo en 45,2% con la aplicación de RF. La co-inoculación con aplicación de MO aumentó la disponibilidad del P inorgánico en la reserva del P lábil. En conclusión, la co-inoculación de estas BSF mostró una mayor eficiencia en la solubilización y mineralización de fuentes de P de baja solubilidad, mejorando la disponibilidad del Fósforo inorgánico (Pi) en la solución del suelo y aumentando la producción del pasto kikuyo, representando una importante estrategia de manejo en praderas establecidas con esta gramínea de pastoreo. (Texto tomado de la fuente) Inoculation of Phosphorus Solubilizing Bacteria (PSB) in association with phosphorus (P) sources can improve the availability of P in the soil, generating more sustainable crop systems, efficient in the use of nutrients with higher productivity. The implementation of these technologies in grazing grasses such as kikuyo in Andisols with high phosphorus retention has been little explored. The objective of this research was to evaluate the productive response of kikuyo grass and soil P dynamics to BSF inoculation with different P sources. The experiment was established on a kikuyo pasture for ten and eight months, using P sources: high solubility (diammonium phosphate (DAP)), low solubility (rock phosphate (RF)) and (compost (MO)); and the co-inoculation of three BSF (Herbaspirillum sp. AP21, Azospirillum brasilense D7, Rhizobium leguminosarum T88). It was found that inoculation with BSF improved soil P availability by 20% with higher enzymatic activity (64%), increasing kikuyo productivity by 45.2% with RF application. Inoculation with MO application increased the availability of inorganic P in the labile P pool. In conclusion, the inoculation of these BSF showed greater efficiency in the solubilization of low solubility P sources, improving the availability of inorganic Phosphate (Pi) in the soil solution and increasing the production of kikuyo grass, representing an important management strategy in established pastures with this grazing grass. Ministerio de Agricultura y Desarrollo Rural Maestría Magíster en Ciencias Agrarias Ciencias Agrícolas - Agricultura, Silvicultura y Pesca - Agronomía

La fasciolosis es una zoonosis provocada por el parásito Fasciola hepatica Linnaeus, 1758, éste para poder desarrollar su ciclo biológico, necesita de un hospedero intermediario (molusco gasterópodo, Lymnaeidae), y un hospedero definitivo (mamíferos, incluyendo al hombre). Esta enfermedad, ha causado pérdidas económicas anuales de $ 200 M en el mundo. El objetivo de la presente investigación fue identificar la prevalencia de F. hepatica en los centros de rastro bovino, determinar las pérdidas económicas, e identificar las características agroecológica en donde se desarrollan los hospederos intermediarios, en la provincia de Imbabura, Ecuador. Se identificó una prevalencia de F. hepatica, de 10,9%, donde el Cantón Otavalo presentó 190 muestras positivas (19,7%), considerándose el punto con mayor prevalencia dentro del estudio. Los bovinos positivos fueron, 102 machos (26,9%) y 277 hembras (73,1%), los cuales pertenecen al biotipo Mestizo (53,5%), Holstein (42%) y Normando (4,5 %), siendo el 78,6% mayores a dos años y 21,4% menores a dos años. Se presentó una pérdida económica anual de $ 69.547,5 dólares americanos. Los 20 biotopos muestreados, se mantuvieron dentro de los valores promedio; distancia del centro poblado 0,7 km, área de 42,8 m2; 31 moluscos por biotopo, pH del suelo 7,1; profundidad del agua 2,3 cm; altitud de 2.019 a 2.772 msnm; temperatura de 20 °C y humedad relativa de 74%. Los moluscos se ubicaron en acequias (55%), charcos (25%), pantanos (10%), riachuelos y el suelo (5%), con presencia de kikuyo (Pennisetum clandestinum Hochst. Ex Chiov, 1903) y totora (Schoenoplectus californicus C. A. Mey., 1850) como especies dominantes. La provincia de Imbabura posee una prevalencia moderada en cuanto a epidemiología por parte de fasciolosis, se confirma que estas zonas presentan un ecosistema apto para el desarrollo del ciclo biológico de la fasciolosis.

The use of organic manures, constitute an alternative to that of polluting artificial fertilizers. In this study, the effect of various levels of hen droppings fertilization on the production of biomass, chemical composition and carrying capacity of P. clandestinum were evaluated at the Research and Experimental Farm (REF) and at the Animal Nutrition and Feeding Laboratory of the University of Dschang, between April and September 2016. A completely randomized block design comparing three nitrogen level of fertilization in hen droppings form (0; 100 and 200 kg N/ha) on 4 m2 plot of P. clandestinum were used. Each treatment was carried out in four replications for a total of 12 experimental plots. Then a sample of 500 g of forage has been collected in the center of each plot, then dried and used for the evaluation of the biomass and the chemical composition of P. clandestinum, according to the level of fertilization and the cutting frequency. The results showed that the fertilization with the hen droppings positively influenced (p tion at the first cutting frequency and the highest value (47.12 cm) was obtained with of 200 kg N/ha rate of fertilization. The biomass of this fodder increased significantly (p s with the increasing cutting of frequency whatever the level of fertilization. Independently of the fertilization and the cutting frequency, the maximum biomass (6.22 t DM/ha) was obtained with the first cutting at the 200 kg N/ha of hen droppings fertilization. The fertilization influenced in variable way the chemical composition of P. clandestinum. The dry matter and organic matter content decrease with the level of fertilization and the highest values (83.79% and 89.39% respectively for the DM and OM) were obtained on the control plot at the third and the first cutting. Moreover, the ash and crude protein contents increased significantly (p

Objetivo. Establecer variaciones de la composición nutricional e incidencia de los contenidos de nitratos y nitritos en el pasto Kikuyo (Cenchrus clandestinus (Hochst. ex Chiov.)Morrone), procedente de cuatro veredas: Peña Blanca, Sirigay, Sabaneca y Quintoque, en épocas seca y de lluvia del municipio de San Miguel de Sema – Boyacá. Materiales y métodos. Parámetros de caracterización nutricional fueron asociados a un análisis de varianza, usando la prueba de Tukey como comparación de medias. Resultados. En la materia seca, se destacan altos contenidos promedios de proteína total (23.48% +/- 3.71), de fibra en detergente neutra (60.86% +/- 3.03), importantes niveles de degradabilidad de la MS en los diferentes tiempos, indicando 62.97% +/- 3.74 para el tiempo 48; así como valores disminuidos en niveles de lignina 4.25% +/- 0.5; de carbohidratos no estructurales (11.44% +/-2.43) y de la relación carbohidratos no estructurales:proteína degradada en rumen (0.84 +/- 0.16). Los niveles de nitratos con un promedio de 2977 ppm +/- 2061, presentaron diferencias significativas para las épocas y veredas, para la época seca en las diferentes veredas el contenido promedio fue de 4728 ppm, siendo 3.9 mayor comparativamente con la época de lluvia. Los niveles de nitritos presentaron contenidos promedios de 2.97 ppm de la MS, contenidos muy disminuidos para ser relacionados como tóxicos. Conclusiones. Se mostró un desbalance en la relación proteína:energía como limitante en la zona para la producción de leche. Los niveles de nitratos fueron considerados como potencialmente tóxicos. Incluye referencias bibliográficas

Land degradation is a global problem leading to a diminished production capacity of the rangelands. The consequence is reduced potential to provide ecosystem services and increased vulnerability to the inhabitants. Biological soil water conservation measures can reverse the trend. Different communities prefer different grass species for rehabilitation as communities vary in location, needs, priorities, preferences and the type of livestock reared. This study, therefore, sought to identify the suitable grass species for soil erosion and rehabilitation from the community in Keekonyoie ward In Narok county, Kenya. Data collection was through individual interviews, focus groups, key informant interviews and field observations. Results showed that level, indicators, causes and impacts are known to the community. Cynodon plectostachyus (76%), Chloris gayana (73%), Pennisetum clandestinum (69%), Cymbopogon citratus (46%) and Themeda triandra (42%) were most preferred for rehabilitation and soil erosion control. The primary reason for the grasses choice was a yearlong provision of livestock feed. Needs and livelihood priorities significantly influence decision-making among the Maa-speaking community in Keekonyoie ward. We recommend consideration of community needs, priorities and preferences in the selection of grass species for rehabilitation to increase the adoption measures that can reverse land degradation Key words: Indigenous knowledge, community perceptions, range grass species, rehabilitation, land degradation, Narok.

The main objective of this study was to determine the effect of irrigation using three different types of waters, namely treated wastewater through membrane bioreactor (MBR) system, treated wastewater via intermittently decanted aerated lagoon (IDAL) process and tap water (TW) on soil pH and electrical conductivity (EC) under kikuyu grass production. No fertilizer was added during the study period (1 year). Irrigation waters and water and soil samples extracted from different soil depths were analysed in laboratory. Considerable changes occurred in soil characteristics over the study period under various treatments. Soil pH increased more than 1 unit under irrigation with treated wastewater produced by the IDAL system while soil irrigated with treated wastewater from the MBR treatment system showed little change and TW irrigated soil evidenced a slight decrease when compared to pH at the beginning of the study. There was also a remarkable increase recorded for EC1:5 of top soils irrigated with treated wastewaters compared to the initial EC of the soil. The results from this study highlighted the benefits of irrigation with treated wastewater from the MBR system due to its lower cost of treatment compared to the IDAL process while providing additional nutrients such as nitrogen and phosphorus from the wastewater for plant growth.

In this work, we describe the structure of the nest of Phyllotis andium Thomas, 1912 in an inter-Andean dry scrub in the south of the Azuay province in Ecuador, and the use of an introduced grass in their manufacture. Observations on sociability and abundance of this species are also presented. These data provide new information on the intraspecific relationships of these rodents and their natural history., En este trabajo describimos la estructura del nido de Phyllotis andium Thomas, 1912 en un matorral seco interandino al sur de la provincia del Azuay en Ecuador y el uso de un pasto introducido en su fabricación. Se presentan también observaciones sobre sociabilidad y abundancia de esta especie. Estos datos proporcionan nueva información sobre las relaciones intraespecíficas de estos roedores y su historia natural.

Treated wastewater, also called as recycled water, is a reliable source of water for various non-potable purposes. One of the most common uses of recycled water has been for irrigation. A soil column study was carried out for a period of one year. The objective of this study was to determine the effect of irrigation using two different types of treated wastewaters on kikuyu grass ( Pennisetum clandestinum ) production in the absence of any kind of chemical fertilisers. Soil irrigated with secondary treated wastewater, MBR (Membrane Bioreactor), resulted in highest annual grass production (16,241 kg of dry-matter per hectare (kg DM/ha)) compared to advanced treated wastewater, IDAL (Intermittently Decanted Aerated Lagoon), and tap water (TW) with annual yields of 7028 and 14,216 kg DM/ha, respectively. Irrigation waters, soil extracted waters and soil samples from different depths of the columns were analysed. Sodium adsorption ratio (SAR), exchangeable cations, electrical conductivity (EC) and pH changed in each experimental column due to different characteristics of applied irrigation waters. The results indicate that high contents of nitrogen and phosphorous in MBR water compensated for the presence of moderate salinity level that contributed to the higher production of grass compared to other two types of irrigation waters. The increase in pH from initial amount of 5.9 to 7.3 in top part of IDAL-irrigated soil may have resulted in low grass yield. This pH increase can be attributed to the high concentrations of cations in the irrigation water in the lack of sufficient amount of nitrogen. Overall, the study demonstrated that a relatively higher grass yield in the absence of any types of fertilisers is possible with recycled water irrigation using secondary treated wastewater. Further, the recycled water irrigation with advanced treatment of wastewater, while costs more, does not result in increased yield benefits.

Two complementary experiments were conducted to investigate the relationships between the canopy structure of Pennisetum clandestinum (kikuyugrass) pastures created by intermittent stocking strategies and daily herbage intake by cattle. The first experiment (Exp. I) evaluated the relationship between different pre-grazing heights (10, 15, 20, and 25 cm) and a single defoliation intensity (50% reduction in the initial heights). In the second experiment (Exp. II), four defoliation intensities (40, 50, 60, or 70% reduction in height) were combined with a single pre-grazing height (25 cm). The following variables were analyzed: i) plant-part composition, herbage mass, and bulk density of the grazing layer; and ii) daily herbage intake. The data were analyzed using orthogonal polynomial contrasts. The Tukey-Kramer test was used to compare daily herbage intake means so that the differences among treatments could be characterized. In general, herbage intake decreased as the pre-grazing canopy height decreased (Exp. I; P = 0.03) and as defoliation intensity increased (Exp. II; P = 0.02). These response patterns were associated with canopy structure, both that existing before and that created during the stocking period. In conclusion, pre-grazing heights lower than 25 cm or defoliation intensities greater than 40% reduce daily herbage intake by cattle in kikuyugrass pastures under intermittent stocking. RESUMO Dois experimentos complementares foram conduzidos para investigar as relações entre a estrutura do dossel de pastagens de Pennisetum clandestinum (capim-quicuiu) criadas por estratégias de lotação intermitente e o consumo de forragem por bovinos. O primeiro (Exp. I) avaliou o efeito de diferentes alturas em pré-pastejo (10, 15, 20 e 25 cm) associadas com uma única severidade de desfolhação (50% das alturas iniciais). No segundo (Exp. II) quatro severidades de desfolhação (40, 50, 60 ou 70% da altura total) foram combinadas com uma única altura inicial (25 cm). As variáveis analisadas foram: i) composição morfológica, massa e densidade do estrato de pastejo; ii) consumo de forragem. Os dados foram analisados por contrastes de polinômios ortogonais. Entretanto, para uma melhor caracterização das diferenças entre tratamentos, optou-se por comparar as médias de consumo pelo teste de Tukey. De modo geral, o consumo de forragem diminuiu com a redução da altura em pré-pastejo (Exp. I; P=0,03) ou com o aumento da severidade de desfolhação (Exp. II; P=0,02), em resposta as estruturas criadas antes e durante o processo de ocupação. Ademais, houve uma aparente abdicação dos animais em compensar estas condições com ajustes no comportamento ingestivo. Concluiu-se que alturas em pré-pastejo menores que 25 cm ou severidades de desfolhação maiores que 40% reduzem o consumo de forragem por bovinos em pastos de capim-quicuiu sob lotação intermitente.

The local ecological knowledge (LEK) and perceptions of grasses were investigated in six semi-arid communal areas in the central Eastern Cape province, South Africa, and compared with field studies and scientific knowledge. Of the total of 21 grasses identified in the field survey, communal farmers had vernacular names only for 11 species. Respondents rated Digitaria eriantha and Pennisetum clandestinum to have the highest (p < 0.05) grazing value. Respondents’ ratings of Eragrostis obtusa and Sporobolus africanus as having similar (moderate) grazing values to Themeda triandra is against the established knowledge. Respondents’ ratings of T. triandra and S. africanus as having higher (p = 0.01) ecological value than the other grasses concur with the scientific knowledge, whereas their nomination of E. obtusa and D. eriantha as providing less ecological benefits than Aristida conjesta disagrees with some ecologists. The study hinted at the complementarity and discrepancies between LEK and scientific knowledge that need ratification. The respondents’ lack of detailed knowledge is suggestive of a gradual eroding of LEK among the local communities that will adversely impact the local people’s ability to implement sustainable rangeland utilisation practice. The current study also recognised farmers’ familiarity as well as training needs that would expound their knowledge and management of grasses.Keywords: communal grazing, ecological value, forage production, grazing value, semi-arid

Pasture meters are typically calibrated to estimate total pasture mass (TPM). Recent studies have shown that animal productivity was driven by the level of utilisation of the top leafy stratum (TLS) rather than the TPM. A study of kikuyu (Pennisetum clandestinum) pasture conducted on two farms located in southeast Queensland, Australia assessed whether pasture mass of the TLS, bottom stemmy stratum (BSS) and TPM can be more accurately estimated by using not only pasture surface height but also pasture density derived from height data captured by a laser sensor. The results indicated that there was a notable improvement of the pasture mass estimates when density was included in the calibration equations. The study also compared the accuracy of the pasture mass estimates between the laser sensor and mechanical pasture meters (rising plate meter and ruler). The results indicated that all devices provided reasonable estimates of pasture mass for TLS, BSS and total (R2 ≥ 0.75). However, pasture mass was estimated with a slightly higher level of accuracy when using the laser sensor in comparison with the other pasture meters, particularly for the top leafy stratum (R2 = 0.81 vs R2 ≤ 0.77).

Being the main constituents of lawns, turfgrass species have been the subject of numerous studies, particularly on their behavior. But if the literature is full of tests carried out under conditions of temperate climate, the knowledge on the behavior of these species in the particular conditions of Morocco remain very limited if nonexistent. The present work is a contribution in this direction. It aims to study the behavior of turfgrass species in order to determine species resistant to edapho-climatic conditions in the eastern Morocco. Thus, a first test was conducted to determine in the laboratory under controlled thermal conditions (25 ± 1 °C) the germination rate and kinetics of five species: Pennisetum clandestinum, Lolium perenne, Festuca arundinacea, Agrostis stolonifera and Poa pratensis. The results obtained showed that the percentage and the germination speed of differ according to the species studied. In fact, Lolium perenne showed the shortest germination time with a germination rate of 92% in 7 days. Germination peaks after 9 days for the species Festuca arundinacea and Agrostis stolonifera with a percentage of 99% and 89% respectively, and at the end of the 10th day for Pennisetum clandestinum of 80%. Poa pratens is had the lowest rate, 61% after a 30 day period. The results prouve that the measured germination velocity through the germination median duration (T50) varies between one day to five days .the species Agrostis stolonifera and Lolium perenne being the fastest to germinate (1 day) and Poa pratensis is the slowest (5 days).

El rastrojo de arroz constituido por tallos y hojas, puede ser un importante subproducto de cosecha del grano de arroz para ser utilizado en la dieta de rumiantes, en razón de su abundante disponibilidad. El aumento de las regulaciones y restricciones sobre la quema de rastrojos, ha estimulado el interés por usar para otros propósitos, incluyendo la alimentación del ganado. La técnica de degradación in situ ha sido ampliamente adoptada para evaluar la tasa de degradación de alimentos en el rumen. El objetivo del trabajo fue evaluar mediante la técnica de degradación ruminal in situ, la degradabilidad de la materia seca (MS) del rastrojo de arroz tratado con seis niveles de urea: 0, 5, 10, 20, 30 y 40 g kg MS-1. Los sustratos secos fueron fragmentados en dos tamaños de partícula: una parte picada a 2 cm y otra parte molida a 2 mm, ambos tipos de sustratos fueron incubados en horno de aire forzado a 40 °C durante 10 días. Se utilizaron ocho vacas provistas de cánula ruminal para los ensayos de digestibilidad in situ, a 48 y 96 horas de incubación en rumen. Cuatro vacas recibieron una Dieta de Alta Actividad Ruminal (AAR) ajustada a consumo de 5 kg MS día-1 de heno de alfalfa (Medicago sativa L.) + heno de una mezcla forrajera (Pennisetum clandestinum Hochst. ex Chiov, Lolium perenne L. y Dactilys glomerata L.) ad libitum + 1.8 kg de concentrado, y cuatro vacas restantes recibieron una Dieta de Baja Actividad Ruminal (BAR) basada en heno de la misma mezcla forrajera y concentrado. Los datos fueron analizados mediante regresión múltiple por pasos sucesivos. Los resultados muestran aumentos en la degradabilidad de la MS con el incremento en el nivel de urea en dietas con AAR y a 96 horas de incubación. El tamaño de partícula no afectó la respuesta animal. Se concluye que este subproducto de cosecha tratado con urea puede ser una importante fuente de fibra para rumiantes en los trópicos

The Brazilian cattle herd (>200 million) contributes, via excreta, 41% of the national emission of nitrous oxide (N2O), but little country-specific information exists on related emission factors and mitigation options. The aims of this study were: (i) to determine the N2O emission factors (EF) for dairy cattle urine and dung in a subtropical pasture and compare them with the 2% EF adopted by the IPCC; (ii) to evaluate the efficacy of the nitrification inhibitor dicyandiamide (DCD) to reduce those N2O emissions; and (iii) to determine if the best mode of DCD application is dissolved into or sprayed on urine and dung. An experiment was conducted in a kikuyu grass (Pennisetum clandestinum) pasture over a haplic Cambisol, in southern Brazil. Fresh urine and dung from Friesian dairy cows were applied with or without application of DCD; DCD was dissolved into the excreta before its application onto the soil, or was sprayed on the excreta patch. Treatments were applied four times, once per each season of 2014 (in different spots, same area). After excreta application, N2O fluxes were monitored in 10 air sampling sessions over 63–68 days, by using closed static chambers. Urine and dung were important sources of N2O, with an average EF of 0.34% for urine and 0.11% for dung; this urges the investigation of related mitigation strategies for Brazilian cattle systems. Yet, those emission factors were not as high as the IPCC default value of 2%, which suggests that this default value may need to be revised for the subtropical region. Additionally, this revision should consider the disaggregation of the EF for urine and dung. As a mitigation strategy, the use of DCD had a potential to curb N2O emission from urine patches, particularly in the cooler seasons of autumn and winter, when it reduced emissions by 60–82% after being dissolved in urine. DCD sprayed on excreta patches significantly reduced emissions in autumn only (by 47%) and thus was less efficient than when dissolved in urine. With respect to dung, there was no clear evidence that N2O emission from that excreta is mitigated by DCD, either dissolved into the dung mass or sprayed over the dung pat. ––

In order to estimate the base temperature (Bt) of growth through the appearance of leaves and calculate the phyllochron for kikuyu grass, three plots were established on three farms in the Provincia of Ubaté (Cundinamarca, Colombia) located at different altitudes (2560, 2640, 3143 m. a. s. l.). Measurements were made in four cycles in a period of eight months. The Bt was estimated by the least coefficient of variation method using a second order regression model and the model obtained was validated by the cross-validation method. The Bt values for the first, second, third and fourth leaf were 4.02, 3.68, 3.93, and 3.62 ° C, respectively. For the appearance of the first leaf, the kikuyu required more thermal time (TT) (97.5 accumulated growing degree days (AGDD)) than for the second (74.2 AGDD), third (73.8 AGDD) and fourth leaf (76.0 AGDD) (p 0.05). There was a tendency to a greater number of days required to reach each leaf stage in the farm located at higher altitude and with lower mean temperature. The validation showed an adequate adjustment (r2 = 0.94) and a substantial concordance (CCC = 0.97) between the observed values and the predicted values for the estimated TT with the Bt value obtained for each leaf stage. The results of Bt for kikuyu grass obtained, will allow to make more precise predictions about the phyllochron and generate growth models close to reality.

Knowledge about the net lactation energy (NLE) contained in the dry matter of grasses is necessary to make decisions about forage and the balance of diets for grazing cattle. Its determination is made in laboratories using wet or dry chemistry methods, which are costly, delayed, and sometimes present sampling- or process-related reliability problems. An algorithm, which analyzes the red-green-blue (RGB) images of grasses taken by drone, has been developed as a technological alternative. This has allowed us estimating the NLE level, reducing costs, and changing the sampling system and analysis method. The objective of the present study was to compare the milk production, which was calculated from the NLE and estimated using the algorithm for analysis of RGB images of grasses (included in the TaurusWebs® software), vs the actual milk production. The study was conducted in 15 dairy farms belonging to the dairy control system of the Colácteos dairy cooperative, which are located in the upper tropical region (Department of Nariño, Colombia). The prairies evaluated were composed of mixtures of Kikuyo (Pennisetum clandestinum), Raigrás (Lolium spp), and False Poa (Holcus lanatus). The result was analyzed using a linear regression model (R²=0.86; R=0.93). In the Student´s t-test, the actual and estimated milk production averages were equal (P>0.05). In conclusion, the NLE calculated using the algorithm satisfactorily explains the study livestock production, and the information generated by the algorithm can be used to calculate the NLE of grasses. RESUMO: O conhecimento sobre a energia líquida de lactação (NLE) contida na matéria seca das gramíneas é necessário para a tomada de decisões sobre forragem e o equilíbrio das dietas para pastagem. Sua determinação é feita em laboratórios usando métodos de química úmida ou seca, que são dispendiosos, atrasados e às vezes apresentam problemas de confiabilidade relacionados a amostras ou processos. Um algoritmo, que avalia as imagens vermelho-verde-azul (RGB) de gramíneas tiradas por drone, foi desenvolvido como uma alternativa tecnológica. Isso nos permitiu estimar o nível de NLE, reduzir custos e alterar o sistema de amostragem e o método de análise. O objetivo do presente estudo foi comparar a produção de leite, calculada a partir do NLE e estimada usando o algoritmo para análise de imagens RGB de gramíneas (incluídas no software TaurusWebs®) versus a produção real de leite. O estudo foi realizado em 15 fazendas leiteiras pertencentes ao sistema de controle de laticínios da cooperativa de laticínios Colácteos, localizada na região tropical superior (Departamento de Nariño, Colômbia). As pradarias avaliadas foram compostas por misturas de Kikuyo (Pennisetum clandestinum), Raigrás (Lolium spp) e False Poa (Holcus lanatus). O resultado foi analisado usando um modelo de regressão linear (R² = 0,86; R = 0,93). No teste t de Student, as médias reais e estimadas de produção de leite foram iguais (P> 0,05). Em conclusão, o NLE calculado usando o algoritmo explica satisfatoriamente a produção animal estudada, e as informações geradas pelo algoritmo podem ser usadas para calcular o NLE das gramíneas.

Soil nitrification (microbial oxidation of ammonium to nitrate) can lead to nitrogen leaching and environmental pollution. A number of plant species are able to suppress soil nitrifiers by exuding inhibitors from roots, a process called biological nitrification inhibition (BNI). However, the BNI activity of perennial grasses in the nutrient-poor soils of Australia and the effects of BNI activity on nitrifying microbes in the rhizosphere microbiome have not been well studied. Here we evaluated the BNI capacity of bermudagrass (Cynodon dactylon L.), St. Augustinegrass (Stenotaphrum secundatum (Walt.) Kuntze), saltwater couch (Sporobolus virginicus), seashore paspalum (Paspalum vaginatum Swartz.), and kikuyu grass (Pennisetum clandestinum) compared with the known positive control, koronivia grass (Brachiaria humidicola). The microbial communities were analysed by sequencing 16S rRNA genes. St. Augustinegrass and bermudagrass showed high BNI activity, about 80 to 90% of koronivia grass. All the three grasses with stronger BNI capacities suppressed the populations of Nitrospira in the rhizosphere, a bacteria genus with a nitrite-oxidizing function, but not all of the potential ammonia-oxidizing archaea. The rhizosphere of saltwater couch and seashore paspalum exerted a weak recruitment effect on the soil microbiome. Our results demonstrate that BNI activity of perennial grasses played a vital role in modulating nitrification-associated microbial populations.

Brazilian fruit culture has great importance in the economy, appearing as the third largest world producer. In this context, weed management becomes indispensable from an agronomic point of view, as they compete for water, light, nutrient and space, causing many losses to the crops of interest. These losses are accentuated as they are not properly controlled, for this reason, a phytosociological survey is carried out, which allows us to know the dynamics of weeds and their correct identification. The objective of this work was to carry out a phytosociological survey of weeds existing in the cultivation of temperate fruit in the municipality of Lavras-MG. The survey was carried out in the Fruit Sector of the Federal University of Lavras (UFLA). A phytosociological survey was carried out on 18 cultivars of Pereira (Pyrus spp.), Seven cultivars of Macieira (Malus domestica L.), 22 cultivars of Pessegueiro (Prunus persica (L.) Batsch), seven cultivars of Raspberry, ten cultivars of Blackberry -Black (Rubus spp.), In addition to an area planted with 11 cultivars of Caquizeiro (Diospyrus kaki L.), a cultivar of Figueira (Ficus carica L.) and 34 cultivars of Quince (Cydonia oblonga and Chaenomelis sinensis L.). The identifications of the weeds were based on material analysis, photographs and consulting the specialized literature, afterwards the identification, there was the classification and analysis of the community structure, grouping it into families, scientific name, common name and as to the cycle plant productive species. Spatial Distribution, Variance, Density, Frequency, Constancy, Dominance, Importance Value, Importance Value Index and Similarity Assessment were evaluated. The phytosociological survey showed that the species Cyperus rotundus was the species with the highest IVI in the cultivation of mulberry, raspberry, apple and quince. While the Cynodon dactylon species had the highest IVI in the cultivation of raspberries, pear and quince. On the other hand, the Brachiaria plantaginea species reached the highest IVI in the cultivation of apple trees. Finally, the Pennisetum clandestinum species reached the highest IVI in persimmon cultivation. La cultura de la fruta brasileña tiene una gran importancia en la economía, apareciendo como el tercer mayor productor mundial. En este contexto, el manejo de malezas se vuelve indispensable desde un punto de vista agronómico, ya que compiten por el agua, la luz, los nutrientes y el espacio, causando muchos daños a los cultivos de interés. Estas pérdidas se acentúan ya que no se controlan adecuadamente, por esta razón, se realiza un estudio fitosociológico, que nos permite conocer la dinámica de las malezas y su correcta identificación. El objetivo de este trabajo fue realizar un estudio fitosociológico de malezas existentes en el cultivo de árboles frutales templados en el municipio de Lavras-MG. La encuesta se realizó en el Sector Frutícola de la Universidad Federal de Lavras (UFLA). Se realizó un estudio fitosociológico en 18 cultivares de Pereira (Pyrus spp.), Siete cultivares de Macieira (Malus domestica L.), 22 cultivares de Pessegueiro (Prunus persica (L.) Batsch), siete cultivares de Frambuesa, diez cultivares de Blackberry -Negro (Rubus spp.), Además de un área plantada con 11 cultivares de Caquizeiro (Diospyrus kaki L.), un cultivar de Figueira (Ficus carica L.) y 34 cultivares de membrillo (Cydonia oblonga y Chaenomelis sinensis L.). Las identificaciones de las malezas se basaron en análisis de materiales, fotografías y consultando la literatura especializada, luego de la identificación, se realizó la clasificación y análisis de la estructura de la comunidad, agrupándola en familias, nombre científico, nombre común y según el ciclo. planta de especies productivas. Se evaluaron la distribución espacial, la varianza, la densidad, la frecuencia, la constancia, el dominio, el valor de importancia, el índice de valor de importancia y la evaluación de similitud. El estudio fitosociológico mostró que la especie Cyperus rotundus era la especie con el IVI más alto en el cultivo de morera, frambuesa, manzana y membrillo. Mientras que la especie Cynodon dactylon tuvo el IVI más alto en el cultivo de frambuesas, peras y membrillos. Por otro lado, la especie Brachiaria plantaginea alcanzó el IVI más alto en el cultivo de manzanos. Finalmente, la especie Pennisetum clandestinum alcanzó el IVI más alto en el cultivo de caqui. A fruticultura brasileira tem grande importância na economia, aparecendo como o terceiro maior produtor mundial. Neste contexto, o manejo de plantas daninhas torna-se indispensável do ponto de vista agronômico, pois competem por água, luz, nutriente e espaço, causando muitos prejuízos às culturas de interesse. Essas perdas se acentuam à medida que não são devidamente controladas, por este motivo, é realizado o levantamento fitossociológico, que permite conhecer a dinâmica das plantas daninhas e sua correta identificação. Objetivou-se com esse trabalho efetuar um levantamento fitossociológico das plantas daninhas existentes no cultivo de frutíferas de clima temperado no município de Lavras-MG. O levantamento foi realizado no setor de Fruticultura da Universidade Federal de Lavras (UFLA). Foi realizado o levantamento fitossociológico em 18 cultivares de Pereira (Pyrus spp.), sete cultivares de Macieira (Malus domestica L.), 22 cultivares de Pessegueiro (Prunus persica (L.) Batsch), sete cultivares de Framboesa, dez cultivares de Amora-Preta (Rubus spp.), além de área plantada com 11 cultivares de Caquizeiro (Diospyrus kaki L.), uma cultivar de Figueira (Ficus carica L.) e 34 cultivares de Marmeleiro (Cydonia oblonga e Chaenomelis sinensis L.). As identificações das plantas daninhas foram baseadas através de análise do material, fotografias e com consulta à literatura especializada, posteriormente a identificação, houve a classificação e análise da estrutura da comunidade, fazendo o agrupamento em famílias, nome científico, nome vulgar e quanto ao ciclo produtivo vegetal das espécies. Foram avaliadas Distribuição Espacial, Variância, Densidade, Frequência, Constância, Dominância, Valor de Importância, Índice de Valor de Importância e Avaliação de Similaridade. O levantamento fitossociológico evidenciou que a espécie Cyperus rotundus foi a espécie com maior IVI no cultivo da amoreira, framboesa, macieira e marmeleiro. Enquanto que a espécie Cynodon dactylon teve o maior IVI no cultivo das framboesas, pereiras e marmeleiros. Por outro lado, a espécie Brachiaria plantaginea atingiu o maior IVI no cultivo das macieiras. Por fim, a espécie Pennisetum clandestinum atingiu o maior IVI no cultivo dos caquizeiros. De acordo com o levantamento fitossociológico, deve-se verificar os métodos de controle utilizados como implementos agrícolas, formas de aplicação de inseticidas (sistêmicos ou contato), o sistema de irrigação que menos contribua para o desenvolvimento das espécies indesejáveis, e assim diminuir competição pela água, luz e nutrientes com o aumento da produtividade.