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Soil and groundwater salinity associated with limited rainfall are the challenges for checking salinity build‐up in semi‐arid regions. This field experiment was conducted to test the impact of deficit saline irrigation (DSI) (in winter) with mulching and tillage on salinity build‐up, yield and nutritive value of rainfed‐forage sorghum. Tillage (reduced, conventional and zero), saline water (8.0 dS m−1) irrigation (100%, 80% and 60% of water requirement [WR] in wheat) and mulch were allocated following split factorial layout. DSI with mulching produced at par wheat and sorghum yield compared with 100WR irrigation with harvested rainwater. Mulching improved wheat grain yield and the soil water content by ~13% throughout the cropping season. Forage sorghum yield was increased by DSI and mulching in the previous season compared with irrigation with 100WR saline water. Reduced tillage declined the neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL) with an increase in cell soluble constituents. DSI and mulching also increased the digestible nutrient, crude protein (CP), ash and reduced ADF of sorghum. Soil salinity showed a negative correlation with CP, positive correlation with ADF, ADL and cellulose. Therefore, it is recommended that DSI and reduced tillage with mulching can be a reliable option for productive use of saline soils and water by cropping system intensification. These results also showed the potential for achieving 2030 agenda for sustainable development goals as well as targets of land degradation neutrality in salt‐affected soils by savings irrigation, doubling cropping intensity and preventing salinity build‐up. [ABSTRACT FROM AUTHOR]

Heracleum mantegazzianum is an invasive environmental weed that is widely distributed in Europe and whose distribution is continually expanding. Novel management methods are required to address its impacts and spread. We studied the use of pyrolysis liquids (PL) as a component of biodegradable mulch and as biobased herbicide to control H. mantegazzianum. A five‐year field experiment was conducted to compare pyrolysis liquid peat mulch (PLM) with plastic PE–mulch, biobased Ökolys® mulch and glyphosate. Application of PL biobased herbicide after stem cutting was studied in a one‐year field experiment. We established that PLM does not control the growth or reproduction of mature H. mantegazzianum effectively in contrast with the other mulching materials and glyphosate. The coverage of H. mantegazzianum differed only in 1 year between application of PLMs and the control. The number of flower stems increased in PLM treatments and in the control, indicating that PLM failed to control reproduction and spread of H. mantegazzianum. PL treatment of cut H. mantegazzianum stems was more effective than application of acetic acid alone. The results suggest that biobased control methods do not provide as effective control of H. mantegazzianum as widely used current methods (plastic mulches and glyphosate). If biobased methods are to be more widely used for controlling H. mantegazzianum, lower control efficacy must be accepted, and they should be used in an integrated approach with other methods. [ABSTRACT FROM AUTHOR]

Rising temperatures and disruption of rainfall patterns due to climate change make water a limiting growth factor even in regions of temperate climates. Thus, producing 'more crop per drop' is of utmost importance. While cover crops provide many benefits to cropping systems, their influence on soil water is discussed controversially. While an increase in transpiration can lead to soil water depletion, the reduction of evaporation in combination with possible additional water inputs could provide a water benefit for a succeeding crop. Occult precipitation could be such an additional water input. The objective of this study was to quantify whether cover crops provide a net water benefit over a bare fallow due to the occurrence of occult precipitation. In a 2‐year experiment, seven different cover crops were cultivated in pure stands and as a mixture under semi‐controlled conditions in a container experiment. Water fluxes and meteorological conditions were closely monitored. Although favourable conditions occurred during both vegetation periods, we found no evidence of occult precipitation. In autumn, soil water was depleted by fast‐growing cover crops. In winter, soil water was recharged due to the early preparation of a mulch layer combined with high winter precipitation while in early spring rising temperatures increased transpiration losses of a winter‐hardy cover crop, leading to a reduction of soil water. For middle European conditions, this shows that (1) living cover crops do not provide any water benefits and that (2) soil water recharge in winter is highly dependent on meteorological conditions and cover crop management. From a water budget viewpoint, negative effects on a succeeding cash crop can only be prevented if cover crops are terminated early enough for replenishment of soil water. [ABSTRACT FROM AUTHOR]

BACKGROUND Tea is an important economic crop in China. Mulching, a modern agricultural practice, can modify the soil microenvironment and maintain the crop yield. RESULTS: To investigate the effect of different mulching modes on tea plant growth, filed experiments were conducted in a Shizipu tea plantation located in Langxi Country (Xuanchen City, Anhui Province, China). Five treatments were carried out in a randomized complete block arrangement: (i) clean tillage (control); (ii) black plastic film; (iii) weed barrier fabric; (iv) rice straw mulch; and (v) intercropping with Vulpia myuros. The effects of different mulch modes on soil temperature, water moisture, soil compactness, root activity, soil enzyme activity and nutrition status on tea yield, quality and economic benefits were compared at the harvest stage. In the present study, compared with other mulch treatments, intercropping with V. myuros significantly reduced the topsoil temperature (to an optimum temperature) and soil compactness, and increased the water holding capacity in the deep soil layer, which contributed to increased tea root activity and respiration. Furthermore, intercropping with V. myuros significantly increased soil enzymes activity, soil organic matter, and the available nitrogen and phosphorus concentrations in the main root zone. Therefore, the stronger tea root activity accelerated nutrition uptake and increased the tea yield and quality‐related components of the tea, thus resulting in a larger average net income. CONCLUSION: Intercropping with V. myuros could serve as a profitable agricultural method for tea production. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND Soil‐dwelling predatory mites of the family Laelapidae are augmentatively released for the biological control of several pests with an edaphic phase in numerous greenhouse crops. Yet, there is no information about the potential of releasing these predators to control pests in open field crops. We tested, during two consecutive years, the potential of augmentative releases of Gaeolaelaps aculeifer, alone or in combination with coco fiber discs as mulch, to reduce the damage caused on citrus fruits by the invasive thrips Pezothrips kellyanus in Mediterranean citrus. In a separate trial, we also compared different mulch types (coco fiber discs, rice husks or a mixture of sawdust and wheat bran) for their potential to support the establishment and population development of the predatory mites after their release. RESULTS: The percentage of unmarketable fruits caused by P. kellyanus was significantly reduced in the plots where G. aculeifer was released. The addition of coco fiber discs did not reduce further the percentage of unmarketable fruits. Sawdust + bran mulch was the most effective in preserving immature and adult predatory mite population after their release. CONCLUSION: Augmentative releases of G. aculeifer have the potential to reduce fruit damage caused by P. kellyanus in citrus. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The invasive shrub Rhamnus cathartica L. (common buckthorn) dominates the understory of many temperate forests of eastern North America. Common buckthorn outcompetes native understory species for light, forming monospecific stands that suppress plant and animal diversity. Removing common buckthorn is a common management priority within its invasive range. In recent years, forestry mowing has become popular in removing common buckthorn. This control method removes a midstory of common buckthorn, increasing light availability to the lower understory (which could favor buckthorn regeneration) and creating a layer of mulch on the forest floor (which could suppress buckthorn regeneration). Here we investigate whether and how increased light availability and increased ground cover (mulch) resulting from forestry mowing affects buckthorn regeneration from the seed bank. We evaluated buckthorn germination, survival, and early growth in response to a factorial combination of shading treatments and buckthorn mulch depth treatments in an oak forest in Minnesota, U.S.A. Increased light availability increased buckthorn seedling survival and growth, whereas increased mulch depth did not significantly affect the number of buckthorn establishing from seed over one growing season and winter. Thus, removing buckthorn by forestry mowing (or any other method) is likely to facilitate buckthorn reestablishment by increasing light availability at the ground. [ABSTRACT FROM AUTHOR]

Weed infestation affects economically relevant orchard properties, including tree performance, yield, and fruit quality negatively, and weeds are therefore often controlled by herbicide application in conventional farming. The addition of organic mulch below tree canopies has been proposed as an alternative reliable practice to suppress weeds and preserve soil moisture in organic farming. Mulching, however, may also affect arthropod pest and natural enemy populations, which highlights the need for simultaneously assessing weed, natural enemy, and animal pest communities in mulch experiments. This study addresses the limited knowledge about nonchemical ground cover management strategies for the control of plant and animal pests in orchards as a major constraint for organic growers. Here, we hypothesize that decisions about ground cover management practices in organic temperate fruit orchards affect the composition of web-building spider communities and their functional role as natural enemies of pest arthropods through effects on weed and insect pest communities. We studied weed, prey, and spider communities, as well as spider diet composition, in four temperate fruit types (apricot, peach, plum, and quince) on a single farm in the Western Cape, South Africa. We established experimental plots with and without addition of dead organic mulch under fruit tree canopies. Addition of organic mulch did not significantly affect weed cover under trees or the taxonomic composition of weed or spider communities over the eight-month study period. However, independent of mulching, the taxonomic composition of weed communities was significantly related to the composition of potential prey and spider communities. These relationships indirectly affected the prey composition of web-building spiders. These results suggest that the identity of weed species in the study orchards had a pronounced effect on the diet composition and functional role of web-building spiders. Future research should focus on the value of individual plant species for the promotion of pest control services provided by spiders across larger spatial scales and with higher levels of replication to allow for wider generalizations. The expected results would not only be relevant for weed control but could also be considered during the development of future flower strips in orchards. [ABSTRACT FROM AUTHOR]

Mulches can improve soil properties, but little is known about nutrient availability in mulched soil that contains plant residues and the effect of mulching with manures. The aim of this study was to determine the effects of mulching with high or low C/N organic materials, in which low C/N materials differed in decomposability, and the presence of wheat straw in the soil on plant growth and N uptake, soil N availability and microbial biomass N within about four months after mulching. Three organic materials were used: mature wheat straw (W, C/N 80), young faba bean shoots (FB, C/N 7), and sheep manure (SM, C/N 8). There were eight treatments differing in amendment methods (mulching or mixing with W or both) and mulching materials (W, FB or SM). Treatments that were only mulched with W, FB or SM are referred to as m‐treatments. In m/s‐treatments, after W was mixed into the soil, W, FB or SM were placed on the soil surface as mulch. Two other treatments included an unamended control and soil mixed with W. Wheat was planted 0, 35 or 70 days after mulching (referred to as 0, 35, and 70 DAM) and grown for 35 days. Faba bean mulch increased shoot dry weight, shoot N uptake and available N compared to wheat or sheep manure mulch, particularly in the m‐treatments. Shoot dry weight was higher in m‐treatments than corresponding m/s‐treatments with the same mulch type. Shoot N uptake was higher in 70 DAM than in 0 DAM in all treatments and 0.3 to three‐fold higher in m‐treatments than the corresponding m/s‐treatments. Microbial biomass N was higher in 0 DAM than in 35 and 70 DAM in most treatments and up to two‐fold higher in m/s‐treatments than the corresponding m‐treatments. Available N in m/s‐treatments was two to six‐fold higher than m‐treatments in 0 DAM, but differed little in older mulch ages of W and SM. It can be concluded that compared to soil with only mulch, mixing of wheat straw into soil reduced plant growth and N uptake, particularly in the early stages of mulching (0 and 35 DAM). However, the presence of wheat in mulched soil may provide a longer lasting source of N for plants and reduce the risk of N leaching from rapidly decomposing low C/N mulch due to greater microbial biomass N uptake than only soil with mulch. [ABSTRACT FROM AUTHOR]

Mulching with forest residues has proved to be highly effective in reducing post‐fire soil losses at the plot scale. However, its effectiveness has not been quantified at the application rates that are typically used in operational post‐fire land management (2–3 Mg ha‐1 using straw), as well as at scales larger than 100 m2. The present study compared post‐fire erosion rates for six convergent hillslopes or swales of 500 to 800 m2, three of which were left untreated while the other three were mulched immediately after the fire with shredded eucalypt bark at a rate of 2.4 Mg ha‐1. Erosion rates were monitored at irregular intervals during the first three post‐fire years, whilst ground cover was assessed yearly. Selected topsoil properties (0–2 cm) such as organic matter content and aggregate stability were determined at a single occasion – two years after the wildfire, for three micro‐environments separately: bare soil, and under mulch/litter and vegetation. Soil losses on the untreated swales decreased with post‐fire year from 2.2 to 0.4 and 0.11 Mg ha‐1 yr‐1 (respectively for the first, second and third post‐fire years), while the mulched swales produced 84%, 77% and 38% less soil losses than the untreated swales. Soil losses also depended on slope aspect, with the north‐facing swales producing less erosion than the west‐facing ones. This could be linked to their significant differences in bare soil, vegetation and stone cover, or a combination thereof. The type of micro‐environment also played a significant role in topsoil properties (stone content, bulk density, resistance to penetration/shear stress, porosity and organic matter content). The present results add to the increasing evidence that forest residues should be duly considered for operational post‐fire land management. Forest residues were highly effective in reducing erosion from swales at application rates as low as the typical 2 Mg ha‐1 of post‐fire straw mulch. © 2019 John Wiley & Sons, Ltd. © 2019 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

During oviposition, female insects utilize a wide variety of cues to find an optimal host for their offspring. These cues may be encountered simultaneously or sequentially, and females must rely on a hierarchical categorization to rank cues for optimal ovipositional choice. During alighting, cues are often encountered at different distances, which may influence hierarchical order. Cues that are observed at longer distances and are experienced first may be more influential on oviposition choice than those experienced at shorter distances. We tested the effects of two long‐distance cues, plant size and habitat structure, and two short‐distance cues, plant nitrogen level and predator presence, on Pieris rapae L. (Lepidoptera: Pieridae) oviposition choice through a series of two‐ and four‐choice tests in both greenhouse and field settings. We found that the long‐distance cues of plant size and habitat structure had the largest impact on P. rapae oviposition in laboratory and field settings, with females preferring large plants without habitat structure. Plant nitrogen level had a smaller impact on oviposition, and the presence of predators did not affect oviposition choice. However, plant size and plant nitrogen level had a synergistic relationship, with more eggs laid on large high‐nitrogen plants compared to large low‐nitrogen or small high‐nitrogen plants, suggesting that optimal cues throughout the entire searching process may be important for P. rapae in choosing a host plant. [ABSTRACT FROM AUTHOR]

Intensification of crop production in Tonga has resulted in a move to mechanical soil preparation, often with a rotary hoe, and a consequent loss in both chemical physical fertility. An experiment was conducted on a clay loam soil (Typic Argiudoll) on the Forestry Vaini Research Station, Tongatapu Island, Tonga, to investigate the effect of a once-off application of mulch on yield and quality of watermelon, maize and capsicum grown in rotation over a 1-yr period. The treatments applied were a nonmulched control, transparent plastic and 200-mm-thick applications of locally available coconut sawdust, guinea grass and mature coconut fronds. The fresh fruit yield of watermelon in all the mulch treatments was 7.3-18.1% higher than in the nonmulched control. There was no significant effect of thick vegetative mulch on maize grain dry matter yield; however, the maize yield was significantly lower in the transparent plastic mulch than in the other treatments. The capsicum marketable fruit yield in the following crop was increased by 49-73% in all the vegetative mulch treatments compared to the non-mulched control. The higher crop yields with the vegetative mulch were attributed to the measured lower soil temperatures and higher soil moisture in these treatments. There was no effect of mulch on soil total N ( TN), but soil total C ( TC), soil labile C ( LC) and the carbon management index ( CMI) were increased. [ABSTRACT FROM AUTHOR]

BACKGROUND Plastic-covered ridge-furrow farming systems for rainfall concentration ( RC) improve the water availability for crops and increase the water use efficiency ( WUE), thereby stabilizing high yields. In this study, we optimized the mulching patterns for RC planting to mitigate the risks of drought during crop production in semiarid agricultural areas. We conducted a 4-year field study to determine the RC effects on corn production of mulching in furrows with 8% biodegradable films ( RCSB), liquid film ( RCSL), bare furrow ( RCSN) and conventional flat ( CF) farming. RESULTS We found that RC significantly ( P > 0.05) increased the soil moisture in the top 0-100 cm layer and the topsoil temperature (0-20 cm) during the corn-growing period. Mulching with different materials in planting furrows further improved the rain-harvesting, moisture-retaining and yield-increasing effects of RC planting. Compared with CF, the 4-year average total dry matter amount per plant for RCSB, RCSL and RCSN treatments increased by 42.1%, 30.8% and 17.2%, respectively. The grain yield increased by 59.7%, 53.4% and 32.6%, respectively. CONCLUSION Plastic-covered ridge and furrow mulched with biodegradable film and liquid film is recommended for use in the semiarid Loess Plateau of China to alleviate the effects of drought on crop production. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Besides direct damage, wildfires can produce striking direct and indirect impacts, including extreme runoff-erosion responses with serious negative consequences for land-use sustainability and downstream values at risk. The best way to reduce post-fire runoff is the rapid application of mulch: a protective cover of straw, needles, wood-based material, or other ground cover. In this study, we assessed the efficacy of forest residue mulching for reducing post-fire runoff across spatial scales on a logged and burnt eucalypt hillslope. Additionally, we assessed the underlying processes involved in the hydrologic responses of burnt areas in central Portugal during the first 2 years after a wildfire, with special focus on soil moisture, soil water repellency, and rainfall. Forest residue mulch reduced post-fire runoff by 50% in both micro-plots (0·25 m2) and hillslope scale silt fence plots (100 m2) during the first year after the wildfire. Runoff in the micro-plots was tenfold higher than the larger plots, regardless of mulching. The main controlling factors for the volume of runoff were rainfall amount (direct correlation) and soil moisture (inverse correlation). Soil water repellency and soil moisture were not affected by the mulch but played a role in the hydrologic response. In contrast, there was no decrease in runoff rate within the first two post-fire years. Forest residue mulching can be an effective post-fire treatment for reducing runoff rates, and the consistent decrease in runoff rates between the two spatial scales suggests that the scaling of runoff was not affected by the mulch. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Cover crops are increasingly being used for weed suppression and to enhance the sustainability of agro-ecosystems. However, the suitability of cover crops for weed suppression in integrated and organic conservation tillage systems is still poorly investigated. Therefore, a 2-year field study at eight sites was conducted to test the weed suppressive potential of six legume-based cover crops, with the aim to reduce herbicide input or mechanical weed management interventions. In all experiments, cover crops were directly sown after cereals before next year's main crop (grain maize or sunflower). The presence of cover crops caused a 96% to 100% reduction of weed dry matter at the four sites managed under integrated production, while effects were lower at the four sited managed under organic production, ranging from 19% to 87 %. Cover crops that covered soil quickly and which produced much dry matter had the best weed suppressive potential. However, their weed suppressing effect was difficult to predict, as it depended on the year of the investigation, experimental site, cover crop species, the speed of soil cover in autumn and the density of the resulting mulch layer in spring. The study demonstrated that cover crops are a useful tool to suppress weeds under integrated and organic conservation tillage practices. Our recommendation for supporting weed management in conservation tillage systems is to use locally adapted cover crops that have rapid establishment, good soil coverage and high dry matter production. However, additional weed management measures are required for reliable weed control under on-farm conditions. [ABSTRACT FROM AUTHOR]

Water-saving rice production systems are inevitable in the wake of severe water shortage in rice-growing regions of the world. Mulches can improve water productivity, yield and quality of rice through increase in water retention. Studies were conducted for two consecutive years to assess the potential role of mulches (plastic and straw) in improving the performance of water-saving rice production systems in comparison with no mulch used and conventionally irrigated transplanted rice. Water-saving rice production systems in this study comprise aerobic rice and transplanted rice with intermittent irrigation. These systems saved water (18-27 %) with improved water productivity more than the conventional system. However, these systems caused a yield penalty of 22-37 %; nevertheless, these yield losses were compensated with the application of mulches under water-saving rice production systems. Both plastic and straw mulches were helpful in improving moisture retention and water productivity (0.18-0.25 kg grain m−3 water) relative to non-mulch treatments (0.19-0.29 kg grain m−3 water). Mulch application was also helpful in reducing the number of non-productive tillers and sterile spikelets, and improving the productive tillers, kernel number and size, and kernel quality. Plastic mulch was more effective than straw mulch in improving water retention, water productivity and reducing spikelet sterility. In conclusion, the mulching improved the soil moisture retention, and thus enhanced the rice water productivity, spikelet fertility, paddy yield and quality of rice. This signifies the importance of mulching in water-saving rice production systems. [ABSTRACT FROM AUTHOR]

This study was conducted in the Mediterranean environment of Central Italy from 2011 to 2013 with the aim of evaluating the effects of winter cover crops and their residues on weed composition in a cover crop-tomato sequence. Treatments consisted of five soil managements (three cover crop species - hairy vetch, phacelia, white mustard, winter fallow mulched with barley straw before tomato transplanting and conventionally tilled soil), two nitrogen fertilisation levels (0 and 100 kg N ha-1) and two weed management levels (weed free and weedy) on tomato. Cover crop residues were arranged in strips on the soil surface and then used as beds for transplanting the tomato seedlings in paired rows. Rotary hoeing was performed in the bare strips between paired tomato rows. At tomato harvesting, the weed aboveground biomass and density was higher in nitrogen-fertilised tomato than unfertilised tomato, except in hairy vetch and barley straw that showed similar values. Hairy vetch used as a cover crop and dead mulch was the most suppressive species with the highest production of residues, while phacelia and mustard were not suitable for controlling weeds. The tomato yield was high in nitrogen fertilised and weed-free treatments, except in barley straw mulch, which showed similar values among the weed management treatments. The mulch strips caused variations in weed species composition that was mainly composed of perennial ruderal weeds, while in tilled soil, the weed flora was dominated by annual photoblastic weeds. [ABSTRACT FROM AUTHOR]

BACKGROUND Interception by plant residues is a major process affecting pesticide persistence and leaching in conservation agriculture. Dissipation and leaching of S-metolachlor and glyphosate was studied in repacked soil columns covered with a mulch of maize and lablab residues. The columns were submitted to two contrasting simulated rainfall regimes: one with light but frequent rain ( LF) and one with less frequent but more intense rain ( HI). In both treatments, columns received the same amount of rainwater by the end of the experiment. RESULTS Decomposing crop residues on the soil surface retained more than 50% of the applied amount of pesticide. S-metolachlor dissipation in mulch residues was faster under the LF rainfall regime. This was attributed to more humid surface conditions, under which mulch decomposition was also faster. The formation of metabolites of both molecules was higher under the LF rainfall regime. However, leaching of S-metolachlor and its metabolites to deeper soil layers was greater under the HI rainfall regime, whereas they accumulated in the surface layer under the LF rainfall regime. Glyphosate remained in the surface soil layer because of its strong adsorption capacity, whereas aminomethylphosphonic acid leached down in small amounts without any difference between the two rainfall regimes. CONCLUSION The impact of mulch residues on herbicide dissipation was strongly dependent on molecule type and rainfall regime. © 2014 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The decomposition and nutrient release temporal patterns of three oil palm residues used as soil mulch were studied. Empty fruit bunches ( EFB; 1000 kg plot−1), Eco-mat (processed EFB carpet; 30 kg plot−1), and pruned palm fronds (180 kg plot−1) were left to decompose (and sampled monthly) on the soil surface for 8 months. The frond's leaflets had the highest initial concentration for most nutrients, and the frond's rachis and Eco-mat the lowest. The order of residue quality and rate of residue mass loss were: leaflets > fronds > EFB > Eco-mat > rachis. EFB however had a higher mass loss rate than the fronds. Residue mass loss and nutrient release rates were faster at the beginning than at the end of the decomposition period. Leaflets released the highest total amount of nutrients (except for K), and rachis the lowest. The fronds released either significantly higher (for N and Ca) or not significantly different (for P and Mg) total amount of nutrients than EFB. Converting EFB into Eco-mat had resulted in nutrient losses (e.g. N, K and Mg) and a residue quality reduction in Eco-mat. This study's results would aid in better soil and oil palm fertilisation management. [ABSTRACT FROM AUTHOR]

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A field study was conducted to determine the effect of a combination of the plastic-covered ridge and furrow rainwater harvesting (PRFRH) with different mulching materials, namely, 0.08-mm-thick plastic film (T1), 10-cm-thick corn straw (T2), 8 % biodegradable film (T3), liquid film (T4), bare furrow (T5) and conventional flat (CF), on corn production, soil water storage and water use efficiency (WUE) in the subhumid areas prone to drought of China (SAPDC). The T1-T5 plots at 0-100 cm depth had higher (P < 0.05) soil water storage than CF, while at 100-200 cm soil layer there was no difference (P > 0.05) among treatments. The T1-T4 plots produced 209-1 107 kg ha−1 more grain yields than the T5 plots. Meanwhile, almost all treatments had WUE over 2 kg m−3. The order of WUE increase among different mulch treatments was as follows: T3 > T1 > T2 > T4. In the case of environmental and economic feasibility, a combination of the PRFRH system with biodegradable film and straw mulches would be an option with high potential to increase crop sustainability in dry land farming systems and can be adopted in many areas without irrigation capability. [ABSTRACT FROM AUTHOR]

The effects of two different soil rehabilitation treatments on runoff, infiltration, erosion and species diversity were evaluated in a shrubland area in Galicia (NW Spain) after an experimental fire by means of rainfall simulations. The treatments compared were: seeding, seeding + mulching and control (untreated). Rainfall simulations were conducted 9 months after fire and the application of soil rehabilitation treatments. A rainfall rate of 67 mm h−1 was applied for 30 min to each runoff plot. Seeding significantly increased plant species richness in the treated plots relative to the control plots, although it had no effect on diversity or evenness. Rehabilitation treatments did not significantly increase soil cover or affect runoff and infiltration. Soil losses were low in all cases, varying from 75·6 kg ha−1 in the seeded + mulched plots to 212·1 kg ha−1 in the untreated plots. However, there were no significant differences in sediment yields between treatments. The percentage of bare soil appeared to be a critical variable in controlling runoff and erosion. Copyright © 2010 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Summary Three thicknesses of composted soil conditioner, and one combined with mulch, surface-applied and then incorporated into the sandy topsoil, were tested against controls for promotion of native plant establishment by direct seeding in construction of a seasonal wetland complex. Located 50 km south of Perth, Western Australia in a Mediterranean climate, the site typically dries out in summer. In wetter seasons ponds intercept contaminants in freeway runoff and act as a buffer for peak flows. The 20 mm thickness of soil conditioner was the most effective. The 40 mm thick 40:60 blend of soil conditioner and mulch was also effective - the mulch can help reduce soil erosion. Composted soil conditioner, typically produced by recycling accumulated municipal waste, counteracts soil organic matter and nutrient depletion. [ABSTRACT FROM AUTHOR]

The need for research and development of effective approaches to weed control continues to increase globally. Adaptive protocols using diverse control methods are often required in ecological restoration as recruitment of native species is highly site-specific, species-specific, and experimental. The use of composted weed refuse to control other weeds may be a practical option; yet, the option is not well studied due to the accompanied risk of introducing weed propagules to areas where weed control is desired. Here, we tested the effectiveness of different physical control techniques including the use of mulch made by composting weed refuse on-site. English ivy ( Hedera helix), a non-native, invasive species in the Pacific northwestern United States, was removed from a heavily invaded site, shredded, and composted. The mulch was compared with other methods of suppressing herb Robert ( Geranium robertianum), another invasive species on-site. Five treatments were tested: flame-weeding, hand-pulling, mulching, hand-pulling followed by mulching, and flame-weeding followed by mulching. The mulch and pull/mulch treatments were the most effective, reducing G. robertianum cover by 92 and 86% of pre-treatment levels, respectively, and suppressing G. robertianum 2.9 and 1.6 times more than the control, respectively. The mechanism behind the effectiveness of the mulch is uncertain, but may be related to weed seed burial or the allelopathic potential of the mulch. Composting one invasive species to use as mulch to control another can be effective and merits trial elsewhere. [ABSTRACT FROM AUTHOR]

The insecticidal effects of Lantana camara L. (flowers, leaves, stems and roots) and the soil where lantana had been growing, on foraging activity and survival of the subterranean termites Coptotermes formosanus and Reticulitermes flavipes were examined in a 3-week experiment. The soil in which lantana had been growing had no effect on termite tunneling and survival. Incorporation of chipped fresh lantana leaves and stems into soil had no effect on mortality but caused significant reduction in tunneling. The 5-cm wide barrier of soil with lantana tissue incorporated effectively repelled groups of both species from penetrating the barrier and thus prevented infestation of a piece of wood on the other side of the barrier. C. formosanus was more sensitive in avoiding the barrier than R. flavipes. Leaves, stems and flowers were more repellent than roots. These results provide preliminary evidence that fresh-cut lantana leaves, stems and flowers may have use as additives to garden mulches against termites. [ABSTRACT FROM AUTHOR]

Increased habitat complexity in agricultural fields can alter the movement of pests into or within a field. Using a mark–release–recapture method with Colorado potato beetle [ Leptinotarsa decemlineata (Say)], we compared the tenure time and dispersal of marked insects released within experimental potato fields to those released at the field borders in three trials in summer 2006. Plots within fields had rye, vetch or no plant residues. Movement of marked Colorado potato beetles into the tilled plots was significantly higher than into vetch or rye cover treatments. The abundance of naturally occurring beetles in the three cover treatments followed the general patterns of the number of marked immigrants over all releases. Marked beetles released inside the potato field tended to move along the release row rather than across rows; this pattern was stronger for the tilled treatment than for the two mulch cover treatments. Marked beetles disappeared from within the potato fields differently, depending on the cover crop treatment, but the patterns were not consistent over the season. Incorporation of dispersal patterns into pest management strategies should improve methods of pest population regulation, especially for the initial colonization of fields. [ABSTRACT FROM AUTHOR]

The article presents a study on organic dust toxic syndrome (ODTS), a noninfectious influenza-like illness, which affects urban landscape workers in Colorado. Among the methods used in the study include interviews of 43 employees regarding their illness and occupational exposures, review of medical records, and examination of Mulch samples for fungi and endotoxins. Findings show that 12% of the respondents had respiratory illness due to prolong exposure to Mulch which is compatible to ODTS. Moreover, Mulch samples were found out to contain high levels of Aspergillus spores and endotoxin which are the possible source for assumed ODTS among workers.

The effects of translucent polyethylene sheeting as a thermal covering to eradicate Pueraria montana (kudzu) were investigated at Clemson, South Carolina on a clay loam. In 2005, the highest reduction of live root crowns was observed where P. montana was covered for the entire growing season (May–October) with a reduction of 42% of live root crowns compared with the control plots. Where P. montana was covered for alternate weeks throughout the growing season live root crowns were reduced by 35%. Covering P. montana for one week and then uncovering for four weeks repeatedly through the season killed 24% of root crowns. In 2006, the second year of treatment to the same plots, the three solarization treatments had similar efficacy of about 97%. The use of polyethylene sheeting appears not to be cost-effective for general control of large P. montana infestations, but may be useful for small patches. [ABSTRACT FROM AUTHOR]

The article presents a study which examined combinations of mulch, strip crops and incorporation of legumes in the improvement of soil fertility, minimization of soil and nutrient loss and to increase farmers' income by promoting locally adoptable crops and cultivation practices on sloping terraced farmlands in the middle hills of Nepal. Strip cropping acts to intercept runoff and encourage in-field sedimentation, and is used to good effect in many countries. Most of the legume crops are resistant to soil erosion and act as cover crops. Soil fertility status, economic return and soil nutrient balance are analyzed.

The extent of Oregon white oak woodland and savanna ecosystems in the U.S. Pacific Northwest has diminished significantly during the past century due to land use changes and fire suppression. Planting Oregon white oak seedlings is often necessary when restoring these plant communities. Our objective was to determine the efficacy of post-planting treatments for establishing Oregon white oak seedlings on sites characterized by low growing season precipitation and coarse-textured soils. We evaluated the effects of control of competing vegetation, tree shelters, fertilization, irrigation, and planting date on growth of planted seedlings. Survival was generally high (90%), but growth rate varied substantially among treatments. Plastic mulch increased soil water content and increased annual seedling height growth by an average of 56% relative to one-time manual removal of competing vegetation. Solid-walled tree shelters reduced browse damage and increased mean annual height growth compared to mesh shelters and no shelter by averages of 7.5 and 10.9 cm, respectively. Controlled-release fertilizer applied at planting did not consistently increase seedling growth. Weekly irrigation (3.8 L/seedling) increased first-year seedling growth only where mulch also was applied. Seedlings planted by late February had greater root growth by summer than those planted in early April. Soil water management was necessary for best seedling growth, and the improved height growth in solid-walled tree shelters allowed the terminal shoot to grow more quickly above the height of animal browse. Our results indicate effective methods for establishing Oregon white oak seedlings, but these results may also be applicable to establishment of other tree species on similarly droughty sites. [ABSTRACT FROM AUTHOR]

Landfills are ideal locations for short-rotation forestry, tree-based bioremediation, and wildlife habitat reconstruction. However, tree survival is reduced by harsh growing conditions and poor soil quality. This study was designed to determine survival of tree seedlings and test effects of different mulch types and depths on edaphic properties and herb emergence on a closed Ohio landfill. In spring 2002, five species of hardwood tree seedlings (Fraxinus pennsylvanica, Robinia pseudoacacia, Prunus serotina, Quercus macrocarpa, and Populus sp.) were planted in a clustered fashion on 35 plots. Each plot received a mulch treatment consisting of one type of mulch (hardwood, leaf, or mixed) at a specific depth (5 or 15 cm) or was designated as a nonmulched control. The status of each seedling and edaphic qualities (soil moisture, temperature, and nutrients) were recorded for two growing seasons. Aboveground herbaceous biomass was sampled at the end of each growing season. We found that survival and growth were species dependent. At the conclusion of the experiment, Fraxinus had the highest survival rate (70%) and Prunus the lowest (7%). The use of leaf mulch (15 cm deep) increased organic matter and various edaphic properties (cation exchange capacity, P, Mg) after the second growing season. Mulch treatments did not significantly affect aboveground herbaceous biomass when compared to nonmulched controls. These results suggest Fraxinus as a good candidate for landfill plantings. Additionally, leaves and yard waste are plentiful and could quickly enrich poor soils on a landfill if left to decompose aboveground. [ABSTRACT FROM AUTHOR]

One of the principal components of the contaminant load in urban stormwater runoff is oil and grease (O&G) pollution, resulting from vehicle emissions. A mulch layer wax used as a contaminant trap to remove O&G (dissolved and particulate-associated naphthalene, dissolved toluene, and dissolved motor oil hydrocarbons) from a synthetic runoff during a bench-scale infiltration study. Approximately 80 to 95% removal of all contaminants from synthetic runoff was found via sorption and filtration. Subsequently, approximately 90% of the sorbed naphthalene, toluene, oil, and particulate-associated naphthalene was biodegraded within approximately 3, 4, 8, and 2 days after the event, respectively, based on decreases in contaminant concentrations coupled with increases of microbial populations. These results indicate the effectiveness and sustainability of placing a thin layer of mulch on the surface of a bioretention facility for reducing O&G pollution from urban stormwater runoff. [ABSTRACT FROM AUTHOR]

Weeds can be suppressed in the field by cover crop residues, extracts of which have been demonstrated to exert chemical inhibition of crop and weed germination and early growth in bioassays. In this study, two complementary bioassays were developed with soil and mulch material originating from a long-term maize–cover crop experiment to determine the relative physical and chemical effect of rye cover crop residues on weed and maize germination and early growth. This was compared with the effect exerted by residue material from the natural vegetation that developed in the crop stubble during the winter before maize sowing. Germination percentage and early growth of maize and two maize weeds, Amaranthus retroflexus and Echinochloa crus-galli, were assessed in a seed incubator in tilled (green manured) and nontilled (surface mulched) soil, with and without N fertilisation, at various dates after cover crop destruction. Responses were compared to those of the same species in a standard soil without mulch or with an inert poplar mulch. A second bioassay was set up in a glasshouse to determine the effect of different quantities of fresh residue material and additional N fertilisation on emergence speed and percentage and on plant vigour during the first 22 days after cover crop destruction. These results were compared with no-mulch controls and poplar mulch controls. Results of these trials were compared with weed density and biomass that developed in the maize crop sown after cover crop destruction. Soil and mulch chemical and biological properties were determined for material collected in the field at different times after cover crop destruction. Chemical properties of the mulch differed only occasionally between the treatments, but variation in cover crop biomass production led to significantly different soil chemical properties. Although soil total phenolic acid content did not always correlate to weed and maize germination and early growth inhibition, soil microbial activity did. In suboptimal conditions, as is often the case in the field, plant residue material exerted both a physical and a chemical effect on maize and weed emergence and early growth. Nitrogen fertilisation and application timing can give the maize crop a competitive advantage with respect to the weeds, but the final response and the practical consequences depended largely on the weed species involved. [ABSTRACT FROM AUTHOR]

To study the effect of background colour on aphid landing on green targets (water pan traps), two field experiments were set up in Hessen, Germany, in 2003. Traps were put onto coloured plastic sheets (13 colours, straw mulch, transparent foil, and uncovered soil, Experiment 1). In Experiment 2, green water pans were again put on coloured plastic sheets (red, white, green, and yellow), and the sheets were either sprayed with insect glue or not. Backgrounds and traps were spectrally characterised with a field radiometer (320–950 nm). Aphid catches were highest in the traps on the uncovered background, and lowest in the traps on white or silver backgrounds. ForBrevicoryne brassicae,Myzus persicae(Homoptera: Aphididae, Macrosiphini) and five further aphid species, there was a significant negative correlation between UV-reflectance (320–400 nm) and log(N + 1)-transformed number of individuals. However, the effect of straw mulch (reduced aphid catches with straw compared to the uncovered background), could not be attributed to differences in UV-reflectance, as UV was almost identical in soil and straw. High numbers of alate aphids were caught in traps with dark backgrounds (e.g. black, dark green), a result which was attributed to the high contrast between the background and target. The substantially higher aphid numbers from targets with bare soil than from targets with spectrally similar black backgrounds were thought to be caused by the structure of the background surface: for alate aphids, landing close to the target on smooth surfaces may induce probing, and the lack of appropriate substrate will result in take-off, whereas soil will not induce probing, and aphids will continue to move towards the green targets. [ABSTRACT FROM AUTHOR]

Large, high-severity wildfires remove vegetation cover and expose mineral soil, ofen causing erosion and runoff during postfire rain events to increase dramatically. Land-management agencies in the United States are required to assess site conditions after wildfire and, where necessary, implement emergency watershed rehabilitation measures to help stabilize soil; control movement of water, sediment, and debris; prevent permanent impairment of ecosystem structure and function; and mitigate significant threats to human health, safety, life, property, or downstream values. One of the most common postfire treatments is broadcast seeding of grasses, usually from aircraft. Non-native annual or perennial grasses typically are used to provide quick, temporary ground cover to hold soil in place until native plants are reestablished. Critics argue that seeded grasses compete with native vegetation and do not effectively reduce erosion. Few data exist on the effectiveness of erosion control; less than half of the studies I reviewed showed reduced sediment movement with seeding. In all vegetation types, successful growth of seeded grasses—enough to affect erosion—appears to displace native or naturalized species, including shrub and tree seedlings. Due to the competitiveness of seeded grasses, they are used to attempt suppression of noxious weeds in some postfire seeding operations. In burned sagebrush range, postfire seeding is frequently used to replace non-native cheatgrass ( Bromus tectorum ) with native or introduced bunchgrasses, with at least short-term success. In recent years, native species and sterile cereal grains have increasingly been used for seeding. Use of aerially applied straw mulch has increased as well, with the risk of weed introduction from contaminated bales. More research on the effectiveness and ecosystem impacts of these alternatives is needed. [ABSTRACT FROM AUTHOR]

Establishment of native plant populations on disturbed roadsides was investigated at Bryce Canyon National Park (BCNP) in relation to several revegetation and seedbed preparation techniques. In 1994, the BCNP Rim Road (2,683–2,770 m elevation) was reconstructed resulting in a 23.8-ha roadside disturbance. Revegetation comparisons included the influence of fertilizer on plant establishment and development, the success of indigenous versus commercial seed, seedling response to microsites, methods of erosion control, and shrub transplant growth and survival. Plant density, cover, and biomass were measured 1, 2, and 4 years after revegetation implementation (1995–1998). Seeded native grass cover and density were the highest on plots fertilized with nitrogen and phosphorus, but by the fourth growing season, differences between fertilized and unfertilized plots were minimal. Fertilizers may facilitate more rapid establishment of seeded grasses following disturbance, increasing soil cover and soil stability on steep and unstable slopes. However the benefit of increased soil nutrients favored few of the desired species resulting in lower species richness over time compared to unfertilized sites. Elymus trachycaulus (slender wheatgrass) plants raised from indigenous seed had higher density and cover than those from a commercial seed source 2 and 4 years after sowing. Indigenous materials may exhibit slow establishment immediately following seeding, but they will likely persist during extreme climatic conditions such as cold temperatures and relatively short growing seasons. Seeded grasses established better near stones and logs than on adjacent open microsites, suggesting that a roughened seedbed created before seeding can significantly enhance plant establishment. After two growing seasons, total grass cover between various erosion-control treatments was similar indicating that a variety of erosion reduction techniques can be utilized to reduce erosion. Finally shrub transplants showed minimal differential response to fertilizers, water-absorbing gels, and soil type. Simply planting and watering transplants was sufficient for the greatest plant survival and growth. [ABSTRACT FROM AUTHOR]

The article presents a study which evaluates the effectiveness of neighbor control in a semiarid grassland in southwestern Saskatchewan, Canada. Investigated is the impact of weather conditions as well as the ecological interactions within the plot. Concluded is the significance of germination on the restoration of the abandoned field.

This work aims at modeling quantitatively the effects of a mulch on the water and heat transfers in the soil-mulch-atmosphere system. The developed model TECmulch derives from the mechanistic model TEC, designed for bare soil. TECmulch accounts for (1) free convection, (2) forced convection, and (3) radiative transfer in the mulch. The mulch formalism does not rely on the classical local gradients theory but on long-distance exchanges. It is based on four parameters that are calibrated on experimental data for two different mulches (corn residue and crushed glass). Experimental data come from la Tinaja's station (Mexico) for corn mulch and Avignon's station (France) for glass mulch. Measurements concern the physical characterization of the soil and the mulch, the evolution of soil water content and temperature, and the radiative balance plus usual climatic data. TECmulch is validated on independent data, compared to the classical theory, and each modeled process is analyzed in detail. [ABSTRACT FROM AUTHOR]

Abstract Sustained-release fertilizer and two kinds of mulch treatments were tested to determine their effects on survival and growth of planted Chamaecyparis thyoides (Atlantic white cedar) on a sandy extremely nutrient-deficient site. Height, basal trunk diameter, dry weight, and concentrations of nitrogen (N), phosphorus (P), and potassium (K) were measured for each treatment. After two growing seasons, survival was very high in untreated controls (mean, 86%) and was not significantly increased by any treatment (significance was assessed at p = 0.05 throughout this work). Stem height and cross-sectional area doubled in unamended plots during the course of the study. Fresh mulch alone caused no additional increase in growth, compared with unamended plots. Decomposed mulch caused a slight but significant increase. Sustained-release fertilizer caused significant increases in height (threefold) and dry weight (approximately sixfold). Combined treatment with fertilizer and mulch gave significantly greater growth responses than did other treatments, increasing heights 4- to 5-fold, trunk cross-sectional areas 4-fold, and dry weights 11- to 21-fold over no-treatment controls. Tissue concentrations of N and P correlated with growth trends, with combinations of mulch and timed-release fertilizer providing the highest values. Though statistically different, the two mulch treatments were similar in their effects on tissue nutrient concentrations. When combined with fertilizer, undecomposed mulch stimulated increases in height and dry weight significantly more than did decomposed mulch. Thus, establishment of C. thyoides on low-nutrient sandy soils is improved by combined soil amendment with sustained-release nutrients and organic mulch. [ABSTRACT FROM AUTHOR]

The article presents an analysis which examines the success of grassland restoration strategies at two sites in the northern Great Plains. It explores the major obstacles faced with grassland restoration, such as competition from introduced species and contingency of native grass established on unpredictable precipitation. It shows that competition from wheatgrass (Agropyron cristatum) was lessened through annual application of a generalist herbicide (glyphosate).

Abstract Smoke, canopy-derived mulch, and broadcast seeds were used to maximize the establishment of Banksia woodland species in sand quarries in Western Australia. Smoke, particularly aerosol smoke, had a positive effect on total seedling recruitment. Pre-mined (woodland) sites showed a 42-fold increase in total germinants and a 3-fold increase in the number of species with aerosol smoke application. Post-mined (restored) sites showed only a 3.6-fold increase in total germinants and a 1.4-fold increase in the number of species. Two water-based smoke chemicals, DC10 (pH 4.5) and SC63 (pH 2.5), increased seedling recruitment at both sites but were not as effective in stimulating recruitment as aerosol smoke. Neither of the chemicals were effective in significantly increasing species richness. Application of aerosol smoke directly to seeds as a pretreatment before broadcasting had no effect on seedling recruitment. Broadcasting of seeds onto restoration sites significantly increased seedling abundance and richness. Application of a single layer of mulch from the canopy vegetation after seed broadcasting gave optimum seedling recruitment. Two layers of mulch significantly reduced recruitment, as did applying mulch before seed broadcasting. For broad-scale restoration, the application of smoke on newly restored sites would be more effectively achieved using smoke water sprayed over the soil surface. Species that do not recruit from replaced topsoil could be effectively recovered from broadcast seed rather than from mulch. [ABSTRACT FROM AUTHOR]

Abstract Natural ecosystems globally are often subject to multiple human disturbances that are difficult to restore. A restoration experiment was done in an urban fragment of native coastal sage scrub vegetation in Riverside, California that has been subject to frequent fire, high anthropogenic nitrogen deposition, and invasion by Mediterranean annual weeds. Hand cultivation and grass-specific herbicide were both successful in controlling exotic annual grasses and promoting establishment of seeded coastal sage scrub vegetation. There was no native seedbank left at this site after some 30 years of conversion to annual grassland, and the only native plants that germinated were the seeded shrubs, with the exception of one native summer annual. The city green-waste mulch used in this study (C:N of 39:1) caused short-term N immobilization but did not result in decreased grass density or increased native shrub establishment. Seeding native shrubs was successful in a wet year in this Mediterranean-type climate but was unsuccessful in a dry year. An accidental spring fire did not burn first-year shrubs, although adjacent plots dominated by annual grass did burn. The shrubs continued to exclude exotic grasses into the second growing season, suggesting that successful shrub establishment may reduce the frequency of the fire return interval. [ABSTRACT FROM AUTHOR]

Abstract Prairies in the Pacific Northwest have been actively restored for over a decade. Competition from non-native woody and herbaceous species has been presumed to be a major cause for the failure of restoration projects. In this research, plugs of the native prairie bunchgrass, Festuca idahoensis Elmer var. roemeri (Pavlick), were grown from seed in a nursery and transplanted into a grassland site dominated by non-native pasture grasses. The growth of the plants was followed for three years, and biomass of all volunteer plants was measured. Before planting, five treatments were applied to the plots: removal of vegetation by burning, removal of vegetation by an herbicide-and-till procedure, soil impoverishment by removal of organic matter, fertilizer application, and compost mulch application. Initial growth of Idaho fescue plugs was greatest with fertilizer and compost mulch. Plants grown in mulched plots were also able to photosynthesize later into the dry summer season. After the first year, plots initially fertilized or composted had the lowest survival rate of Idaho fescue. Impoverished and herbicide-and-till plots had the greatest 3-year survival. Mulched plots supported the greatest weed growth after three years. Stressful environments give a competitive advantage to Idaho fescue in prairie restoration projects. As weedy species increase, growth and survival of Idaho fescue decreases. [ABSTRACT FROM AUTHOR]

AbstractThe assessment of the importance of soil aeration for various plant characteristics and environmental conditions is necessary to evaluate the oxygen relations to the crops. The root environment as a solid-liquid matrix depends upon soil structure and moisture condition. A limited oxygen supply restricts the root development and also reduces the nitrogen fixation in peanuts. Soil surface conditions can be altered by mulching and plays a significant role in protecting the plants against deficient aeration during critical periods of growth phases. The effects of eight mulching treatments (rice husk, rice husk-incorporated, paddy straw, sawdust, water mulch, clear polyethylene, black polyethylene and control) on the soil oxygen diffusion rate (ODR) during the various growth phases of peanut crop (Arachis hypogaea L.) were investigated on a lateritic sandy loam soil (ultisols). These experiments were conducted for two consecutive seasons. ODR values were higher in mulched plots. With the progress of growth stages and also in deeper soil depths, the differences between the values of ODR among treatments narrowed down. The influence of mulches on other physical edaphic properties like bulk density, aeration (noncapillary) porosity and soil temperature were also studied. Mulches reduced the surface crusting and thereby soil bulk density; and increased the aeration porosity and ODR. Soil temperature was higher under plastic mulches whereas vegetative mulches suppressed it. [ABSTRACT FROM AUTHOR]

Field studies were conducted in 1991 and 1992 on a sandy loam soil in the derived savanna zone of south-western Nigeria to assess the effect of the underground organs of Imperata cylindrica (L.) Raeuschel on maize grain yield. Total dry matter of I. cylindrica in abandoned arable land averaged 16 t ha-1 and rhizomes contributed 56% of this. Rhizome removal from soil before planting maize significantly increased maize yield relative to hoe tillage or slashing of I. cylindrica shoots before planting maize. Digging up rhizomes before planting maize and weeding the crop twice gave a yield reduction of only 23% compared with weed-free crops with rhizomes removed. Grain yield reduction was 51% in plots where rhizomes were only fragmented by hoe tillage and the crop was weeded twice. Grain yield was 62% less when maize was grown in slashed plots with intact rhizomes that were weeded four times (farmers’ practice). Slashing without additional weeding resulted in crop failure in maize. [ABSTRACT FROM AUTHOR]

Soil evaporation, transpiration, evapotranspiration, and yield of pepper as affected by mulch and live amounts of irrigation water were studied in greenhouse pot experiments during 1996 (March 26-July 13). Five different amounts of irrigation water were imposed on covered and open soil surface clay loam soil in five replicates. Water losses by evaporation and or transpiration were measured daily by weighing. Irrigation water was applied once weekly. The amount of irrigation water added to each treatment was determined from the differences in weights. Covering soil surface reduced the required amount of irrigation water. With deficit (under) irrigation, the reduction in applied irrigation water was about 14 %, and increased to 29 % with excess (over) irrigation. Transpiration in covered soil surface treatments were higher than transpiration in open soil surface treatments with limited irrigation water applied. With limited (deficit) irrigation, increasing irrigation water applied decreased the percentage of soil evaporation and the contribution of soil evaporation to crop evapotranspiration. With excess irrigation, increasing water applied increased the percentage of soil evaporation and its contribution to the total evapotranspiration. Soil evaporation reduced pepper yield significantly, and this might be owing to the reduction in the available soil water associated with limited- to-complete irrigation. [ABSTRACT FROM AUTHOR]

Effects of irrigation, mulch and nitrogen on yield and composition of Japanese mint (Mentha arvensis L. subsp. haplocalyx Briq. var piperascens) oil were studied using a replicated experiment. Two harvests were obtained 120 days after planting and 75 days after the first harvest. Significantly higher dry matter and essential oil yields were obtained with frequent irritations (50 mm Cumulative Pan Evaporation), application of mulch and Nitrogen. The economic optimum rate of N was 215 Kg ha-1. The essential oil from the first harvest was richer in menthol (78.8%) than the oil obtained from second harvest (75.2%). Soil moisture extraction was maximum between 15 and 30 cm soil depths. Consumptive use, water use efficiency and moisture use rate were maximum under higher irrigation levels and mulch application which reflect that more availability of moisture in soil profile with frequent irrigations and application of mulch. [ABSTRACT FROM AUTHOR]

Soil hydrothermal regimes which can enhance seed germination, seedling emergence and development so that the late planted safflower (Carthamus tinctorius L.) can be competitive in comparison to normally planted crop need to be studied and suitabily modified. Therefore, a split-plot field experiment was conducted in Vertisols during 1984-85 and 1985-86 post-rainy season to determine the influence of planting date (PD1: Oct. 20; PD2: Oct. 30; PD3: Nov. 10; PD4: Nov. 20; PD5: Nov. 30; PD6: Dec. 10; and PD7: Dec. 20), irrigation (I1: come-up irrigation and I2: I1 + branching stage) and straw-mulch (M0: No mulch and M1: paddy straw mulch at 10 t ha-1) and the mteraction on the growth and development of safflower (Cultivar, JSF-7). Germination of safflower commenced earlier in October planting, but it was significantly higher in November and December plantings. Initiation of emergence and completion of germination required 153 and 307 cumulative degree days (CDD soil), respectively. Days to maturity decreased from 163 to 140 in 1984-85 and from 156 to 137 in 1985-86 with delay in planting from October to December. Height, number of branches, number of capsules, seed yield per plant and 1000 seed weight were significantly affected by the different treatments. Planting of safflower on October 30 and November 10 in both the seasons produced significantly higher seed yield than the other plantings. Branching stage irrigation (I2) and straw mulching significantly improved all the yield attributes and seed yield of safflower in both the seasons. The water use efficiency (WUE) was higher in early plantings than in the later plantings. Higher WUE was obtained under come-up irrigation. Straw mulching increased the WUE, moderated the diurnal variations in soil temperature and provided a better thermostable regime more congenial for plant roots which resulted in increased safflower seed yield. [ABSTRACT FROM AUTHOR]