Unmulched Control Research Articles

Comparative Analysis of Biodegradable Mulches on Soil Bacterial Community and Pepper Cultivation

Biodegradable mulch films (BMFs) are becoming increasingly popular in agricultural practices. However, research on the ecological impact of biodegradable mulch films on pepper–soil systems is still scarce. To compare the differential effects of BMFs and polyethylene (PE) mulch on soil chemical properties, soil bacterial community composition, and pepper cultivation, a study was conducted encompassing eight distinct treatments. These treatments included three varieties of polybutylene adipate terephthalate (PBAT) combined with polylactic acid (PLA) mulches: PP-JL, PP-SD, and PP-SH; a black polypropylene carbonate mulch (PPC-BK); a brown PPC mulch (PPC-BR); a polyethylene (PE) mulch; straw mulching (NCK); and an uncovered control (PCK). After applying mulches for 129 days, most PPC and PBAT + PLA films had reached the rupture phase, whereas the PE film was still in the induction phase. Pepper yield was obviously higher in all mulched treatments (4830 kg hm−1) than in the un-mulched control (3290 kg hm−1), especially the BMF PP-JL treatment, which showed the most notable improvements in yield. Although BMF treatments maintained a lower soil temperature than the PE film mulch, they were still higher than the un-mulched control. Furthermore, the soil bacterial community composition and ecological network were not markedly affected by different mulching conditions. However, the PP-SH treatment significantly increased the abundance of Pseudomonas, Nitrosomonas, and Streptomyces genera. Moreover, Lactobacillus and Gp16 were substantially more abundant in the PPC-black (BK) and PPC-brown (BR) treatments compared to the PE mulching treatment. This study could provide valuable insights into the ecological benefits of BMFs in pepper cultivation. However, as our experiments were conducted for only one season, it is imperative to undertake long-term experiments across consecutive seasons and years for a thorough understanding and comprehensive study.

Biodegradable plastic mulch films increase yield and promote nitrogen use efficiency in organic horticulture

Plastic film mulches (PFM) are used extensively due to their ability to increase yield and suppress weed emergence. Their effects on plant-soil-microbial interactions, however, are less well understood. Organic systems rely on the supply of nutrients from organic sources (e.g., manures and fertility-building leys) and where poor N availability often limits yield. The issue is compounded by horticultural crops (e.g., lettuce) with a high N demand, but which are inefficient at recovering N from soil. The effect of PFM on the mineralisation of organic fertilisers and its interaction with other agronomic factors such as planting density is also less well-researched. We hypothesised that biodegradable PFM would be a useful tool to increase the efficiency of N management in organic horticulture by increasing the supply of available N leading to increased crop N uptake and crop yield, and simultaneously reducing N losses during the growing season. We conducted two field experiments under a temperate maritime climate with lettuces grown with either conventional (LDPE) PFM or a polylactic acid-based biodegradable PFM alongside un-mulched controls. The first experiment involved black or white coloured PFMs and two planting densities while the second experiment involved treatments with and without addition of poultry manure. Overall, yields were increased by 39% in both experiments with PFM, while soil mineral N concentrations were up to 5 times higher with PFM than without. Measurements of soil organic matter (SOM) turnover (Tea Bag Index) and soil CO2 efflux indicated a more rapid decay of SOM in the presence of the PFM. The use of PFM also promoted N use efficiency (NUE) by 300% in the presence of poultry manure. Denser planting with PFM resulted in proportionately higher yields. Higher yield and higher N concentrations (5-10%) in crop tissue in mulched plots resulted in higher total N uptake, however, total N uptake was low compared to soil concentrations: mulching with biodegradable PFM resulted in higher residual mineral N than un-mulched plots (77-147 mg kg-1 vs. 19 -70 mg kg-1). Our results are consistent with reduced N losses to the environment during the growing season and increased mineralisation under PFM. In conclusion, our findings support the adoption of PFM for organic horticulture and show that biodegradable PFM perform similarly to LDPE-based PFMs.

Temporal Impact of Mulch Treatments (Pinus halepensis Mill. and Olea europaea L.) on Soil Properties after Wildfire Disturbance in Mediterranean Croatia

On 28 July 2019, in the hinterland of Šibenik City, 900 ha were affected by wildfire of moderate to high severity. This study aims to evaluate the effects of two mulch treatments—needles of Pinus halepensis Mill. (PM) and leaves of Olea europaea L. (OM), as compared to an unmulched control (UM)—on soil quality. The study was conducted over 15 months, and soil samples were collected every 3 months. The studied soil properties were soil water repellence (SWR; composite, 1–2, 0.5–1, 0.5–0.25, <0.25 mm), soil hydraulic conductivity (SHC), mean weight diameter (MWD), water stability of aggregates (WSA), soil pH and electrical conductivity (EC), soil organic matter (SOM), total sulphur (TS), total carbon (TC), total nitrogen (TN), extractable phosphorus (P2O5), and available potassium (K2O). Six principal component analyses (PCA) were applied to observe the temporal dynamics of the soil properties studied for each sampling date. Mulching increased the aggregate stability (MWD and WSA) and improved SHC. SWR was only indicated on the first sampling date. Soil pH and EC showed high variability due to natural soil processes and vegetation regrowth. PM showed higher efficiency in increasing the TS, TC, and SOM, while OM increased soil P2O5 and K2O. Both mulch treatments increased the soil nutrient content, but the effect was variable due to the different chemical compositions of the material. Using native mulch is recommended because it improves soil quality.

AGRO-ECONOMIC IMPACT OF ORGANIC MULCHES ON WEED DYNAMICS AND PRODUCTIVITY OF RAINFED WHEAT (Triticum aestivum L.)

Wheat is a widely grown cereal crop under rainfed conditions of semi-arid areas of the world including Pakistan. Unfortunately, its yield remains low due to heavy weed infestation and scarce moisture supply in the root zone from erratic rainfall. Therefore, a field experiment was conducted to observe the influence of different organic mulches on the soil moisture, weeds, growth and yield of wheat crop. Four organic mulches i.e wheat straw sawdust, rice straw and rice husk were applied up to 2 inches surface layer between the rows of wheat crop. Application of wheat straw mulch conserved the highest soil moisture (72.3%) at 0-15cm depth six weeks after sowing and caused maximum weed suppression with 81.17% weed control efficiency and 63.70% weed control index as compared to unmulched control. Maximum plant height (70.8cm), productive tillers (137.33 m-2), grain weight per spike (2.37g), grains per spike (52.3), 1000-grain weight (50.66 g), biological yield (9393.9 kg ha-1), grain yield (3665.6 kg ha-1), harvest index (38.60%) and benefit-cost ratio (1.69) were observed in rainfed wheat crop treated with wheat straw mulch. Wheat crop total rainfall use efficiency followed the order of wheat straw > rice straw > saw dust> rice husk> control. The highest weed density and dry weight while lowest soil moisture and grain yield were recorded with no mulch and rice husk treatments.

Assessing Biodegradable Mulch Duration and Nutsedge Suppression during Late Summer Cucumber Production in Mississippi and Louisiana

Environmental concerns as well as labor costs associated with the use of polyethylene plastic mulch have turned producers’ focus to alternative mulch treatments. A preliminary study was conducted to evaluate nutsedge control, mulch degradation, and cucumber yields on biodegradable mulches at two locations (Louisiana and Mississippi). Mulch treatments included two paper-based mulch products, two biodegradable plastic mulches, the industry standard non-biodegradable black plastic mulch, and an unmulched control. The heavy weight paper-based mulch and light weight paper mulches in the Louisiana location were reduced to 50% or less coverage at the end of the study. Similarly, the paper-based mulches both degraded below 40% at the conclusion of the study at the Mississippi location. The heavy weight paper mulch was able to hold back nutsedge (p ≤ 0.05) at similar rates as the two biodegradable plastic mulches and industry standard plastic mulch, while the light weight paper mulch and unmulched plots were ineffective at reducing emerged sedges. There were no statistical differences in nutsedge control (averaging < 14 emerged plants per 1.5 m subplots) between all mulch materials at the conclusion of the study in the Mississippi location. Combining both states yield data, the heavyweight mulch (8.7 fruit, 5.3 lb) performed comparably to the industry standard plastic mulch (5.8 fruit, 3.5 lb) in terms of both average fruit number and average weights harvested off 9.1 m rows at each harvest date.

Photosynthetic light response models for spring wheat mulching treatments in a northwestern China desert oasis

AbstractIn the desert oasis areas of northwestern China, mulching treatments are an effective method for alleviating drought in agricultural production. Four mulching treatments of polyacrylamide (PAM), which is a water retention agent; plastic film; stones; straw; plus an unmulched control treatment were used in the field to explore their influence on soil water content (SWC), soil temperature, the net photosynthetic rate (Pn), leaf area index (LAI), and yield in spring wheat (Triticum aestivum L.). Six light response models were used to simulate the light response of wheat. A significant difference was found between straw and the control vs. the other mulching treatments in terms of grain yield and yield components of spring wheat (p < .05). Under the film treatment, the yield increased by 9.8–16.9% and the water use efficiency (WUE) increased by 20% in 2012 and 23% in 2013. Compared with PAM, stone, straw, and the control, the film mulch had the largest maximum photosynthesis and the largest rate of light adaptation. The nonrectangular hyperbolic had the smallest error and simulated the best photosynthetic light response. Compared with the control treatment, the soil temperatures were reduced by a mean of 8.5–11.3 °C and the average SWC increased by 5.5–3.2% under all mulching treatments. However, SWC had a greater effect on Pn than soil temperature during the growth season under the mulching treatments, which increased yield in this arid environment. Film mulching was the best mulching treatment for spring wheat in this desert oasis.

High Biomass Productivity of Short-Rotation Willow Plantation in Boreal Hokkaido Achieved by Mulching and Cutback

Weed control, which is commonly achieved by herbicides, is important in successfully establishing short-rotation coppice (SRC) of willow. In this study, we examined agricultural mulch film as a means of effective weed control and the influence of cutback practice (coppicing the first year’s shoot growth in the winter following planting) on biomass production in boreal Hokkaido, Japan. One-year-old cuttings from two clones each of Salix pet-susu and S. sachalinensis were planted in double-rows at a density of 20,000 plants ha−1. All plants were harvested three growing seasons after cutback. Average oven-dried biomass yield was 5.67 t ha−1 yr−1 with mulching, whereas it was 0.46 t ha−1 yr−1 in the unmulched control with a weed biomass of 4.13 t ha−1 yr−1, indicating that mulching was an effective weed control. However, weeds grew vigorously on the ground between mulch sheets and their dry biomass amounted to 0.87 t ha−1 yr−1. Further weeding between the mulch sheets enhanced the willow biomass yield to 10.70 t ha−1 yr−1 in the treatment with cutback. In contrast, cutback even reduced the willow yield when there were weeds between the mulch sheets. This negative effect of cutback on the willow yield resulted from nutrient competition with weeds; there was similar leaf nitrogen content and dry biomass per unit land area for the weeds and willows combined in the control and mulching treatments. These results suggest that growing SRC willow is feasible in boreal Hokkaido if combined with complete weed control and cutback, and is facilitated by using mulch film.

Effects of treated greywater irrigation regimes and mulches on yield of Capsicum chinense under surface drip irrigation system

A field study was conducted to determine the effects of combine treatment of greywater application rates and mulches types on growth and yield of Capsicum chinense in Omu-Aran, Nigeria. Greywater (GW) was treated using a pilot-scale horizontal sub-surface flow constructed wetlands (HSSF CW) vegetated with Canna indica plants. Four irrigation levels (60, 80, 100 and 120% of ETc) and four mulches types (Black plastic film BM, Silver plastic film SM, Rice straw RS and un-mulched Control) were applied to the potted plants. The experiment was laid out in a split-plot design, with main plots as irrigation levels and mulches types as sub-plots. C. indica plants were found to be effective in GW Phytoremediation treatment in CW. The maximum fruit yield was observed for T10 (I100SM) 4666.70 kg/ha due to reflective mulch ability to increase light and heat to plant resulting to a higher yield. Significant difference was observed between the mean yield of I60 and other irrigation regimes, whereas between I80 to I120 there was no significant difference in mean yield recorded. Silver mulch combined with full irrigation with treated greywater effluent was found to be the best of all treatments in the study.

Effect of nylon mulch and some plant growth regulators on water use efficiency and some quantitative traits in onion (Allium cepacv.) under water deficit stress

In order to investigate the effects of plant growth regulators (PGRs) and mulch on some traits of onion under water deficit stress, a split-factorial experiment based on Randomized Complete Block Design with three replications was conducted in Iran in 2016 and 2017. The main plot consisted of water deficit stress treatment at three levels (100%, 80% and 60% of water requirement), and sub-plots consisted of a dark nylon mulch application and an unmulched control, and PGRs six levels (zero, salicylic acid 0.5 mM, methyl jasmonate 5 and 7.5 mM, and 24-epibrasinolide 0.5 and 1 mM, respectively). Final yield under water deficit stress (60% water requirement) decreased by 30% compared to control (100% water requirement). On the other hand, the use of plastic mulch increased the yield by 29%. Interaction of water deficit stress and PGRs on leaf number, fresh and dry weight of plant, plant height, bulb length and diameter, early yield and final bulb yield were significant and the effect of regulators was mainly effective in severe water deficit conditions. The highest crop yield of 52.55 ton per hectare was obtained from 1 micromolar brassinolide treatment under non-stress conditions which had a 9% increase compared to control under non-stress conditions and 28% increase compared to control under severe water deficit stress.

The Effect of Irrigation Frequency, Phosphorus Fertigation, and Cultivar on Levels of Phenolic Compounds in Sweet Cherries

This work examined the effect of irrigation frequency and phosphorus (P) fertigation on the levels of phenolic compounds present in two sweet cherry cultivars, ‘Skeena’ and ‘Cristalina’, over three growing seasons (2012–14). Two irrigation treatments were tested: a high irrigation frequency (I1) and a low irrigation frequency (I2). Both irrigation treatments applied the same quantities of water [100% evapotranspiration (ET)], but the high irrigation frequency applied water four times daily (0300, 0900, 1500, and 2100 hr) whereas the low irrigation frequency was applied at one time (0900 hr) every second day. Three soil management treatments were investigated, including 1) an unmulched control receiving no P, 2) a 10-cm waste wood mulch receiving no P, and 3) a treatment involving annual fertigation of 20 g P/tree at full bloom as ammonium polyphosphate. It was determined that cultivar was the most important factor affecting levels of phenolic compounds in sweet cherries, with generally greater levels associated with ‘Skeena’. The effect of different irrigation and fertilization strategies showed less promising results in terms of influencing levels of phenolic compounds. Both severe and mild water stress did not show an appreciable influence on increasing levels of phenolic compounds in cherries. Furthermore, severe water stress, which occurred during 2012, was associated with the lowest annual concentration of phenolic compounds and an economically unacceptable reduction in fruit size. Phosphorus fertigation influenced cherry phosphorus status positively by increasing leaf and fruit P concentrations consistently, yet these fruit exhibited lower levels of phenolic compounds.

Mulch and planting depth influence potato canopy development, underground morphology, and tuber yield

The response of potato (Solanum tuberosum cv Haryeong) to mulching and different planting depths was evaluated during 2010–2013. Two different plastic mulches, black and clear polyethylene (PE) were compared with the unmulched control and seed tubers were planted at 5-, 10-, 15-, and 20-cm depths in each treatment. The objectives were to determine how mulching and planting depth affected the canopy development, underground morphology, and tuber yield. Early emergence, canopy development and tuber growth rate were improved in the mulched treatment; while delayed or decreased as the depth of planting increased. The number of stems per plant increased as seed pieces were planted closer to the soil surface in two of the four seasons, but was not affected by mulches except for 2012. Stolon length was longest in black mulches, especially on upper part of underground stem, but it was long on lower part of the stem in unmulched potatoes. Percent tuber bearing stolons were increased in the mulches and deep (10–20cm) planted potatoes. Particularly, on the lower part of underground stem, a higher percentage of tubers were formed irrespective of mulches and planting depth. Harvest index was significantly higher in clear PE mulches in two of the four seasons while it was not affected by planting depth. Mulching potatoes produced higher total and >80g yields, while varying the depth of planting affected the total yield which was lower in the deepest (20cm) planted potato.

Effects of Mulching on Soil Properties and Growth of Tea Olive (Osmanthus fragrans).

Different mulches have variable effects on soil physical properties and plant growth. This study aimed to compare the effects of mulching with inorganic (round gravel, RG), organic (wood chips, WC), and living (manila turf grass, MG) materials on soil properties at 0–5-cm and 5–10-cm depths, as well as on the growth and physiological features of Osmanthus fragrans L. ‘Rixianggui’ plants. Soil samples were collected at three different time points from field plots of O. fragrans plants treated with the different mulching treatments. Moisture at both soil depths was significantly higher after mulching with RG and WC than that in the unmulched control (CK) treatment. Mulching did not affect soil bulk density, pH, or total nitrogen content, but consistently improved soil organic matter. The available nitrogen in the soil increased after RG and WC treatments, but decreased after MG treatment during the experimental period. Mulching improved plant growth by increasing root activity, soluble sugar, and chlorophyll a content, as well as by providing suitable moisture conditions and nutrients in the root zone. Plant height and trunk diameter were remarkably increased after mulching, especially with RG and WC. However, while MG improved plant growth at the beginning of the treatment, the ‘Rixianggui’ plants later showed no improvement in growth. This was probably because MG competed with the plants for water and available nitrogen in the soil. Thus, our findings suggest that RG and WC, but not MG, improved the soil environment and the growth of ‘Rixianggui’ plants. Considering the effect of mulching on soil properties and plant growth and physiology, round gravel and wood chips appear to be a better choice than manila turf grass in ‘Rixianggui’ nurseries. Further studies are required to determine the effects of mulch quality and mulch-layer thickness on shoot and root growths.

Integrated use of fertilizer micro-dosing and Acacia tumida mulching increases millet yield and water use efficiency in Sahelian semi-arid environment

Limited availability of soil organic amendments and unpredictable rainfall, decrease crop yields drastically in the Sahel. There is, therefore, a need to develop an improved technology for conserving soil moisture and enhancing crop yields in the Sahelian semi-arid environment. A 2-year field experiment was conducted to investigate the mulching effects of Acacia tumida pruning relative to commonly applied organic materials in Niger on millet growth, yields and water use efficiency (WUE) under fertilizer micro-dosing technology. We hypothesized that (1) A. tumida pruning is a suitable mulching alternative for crop residues in the biomass-scarce areas of Niger and (2) combined application of A. tumida mulch and fertilizer micro-dosing increases millet yield and water use efficiency. Two fertilizer micro-dosing options (20 kg DAP ha−1, 60 kg NPK ha−1) and three types of organic mulches (millet straw, A. tumida mulch, and manure) and the relevant control treatments were arranged in factorial experiment organized in a randomized complete block design with four replications. Fertilizer micro-dosing increased millet grain yield on average by 28 %. This millet grain yield increased further by 37 % with combined application of fertilizer micro-dosing and organic mulch. Grain yield increases relative to the un-mulched control were 51 % for manure, 46 % for A. tumida mulch and 36 % for millet mulch. Leaf area index and root length density were also greater under mulched plots. Fertilizer micro-dosing increased WUE of millet on average by 24 %, while the addition of A. tumida pruning, manure and millet increased WUE on average 55, 49 and 25 %, respectively. We conclude that combined application of micro-dosing and organic mulch is an effective fertilization strategy to enhance millet yield and water use efficiency in low-input cropping systems and that A. tumida pruning could serve as an appropriate mulching alternative for further increasing crop yields and water use efficiency in the biomass-scarce and drought prone environment such as the Sahel. However, the economic and social implications and the long-term agronomic effects of this agroforestry tree in Sahelian millet based system have to be explored further.

Effect of Tithonia diversifolia mulch on Atta cephalotes (Hymenoptera: Formicidae) nests.

Recent studies have shown an insecticidal effect of Tithonia diversifolia (Hemsl.) Gray (Asterales: Asteraceae) foliage on workers of Atta cephalotes L. and inhibitory effects of this plant on the growth of the symbiotic fungus Leucoagaricus gongylophorus (A. Müler) Singer. To evaluate the potential of T. diversifolia as a biological control treatment of this important pest, we assessed the effect of green manure (mulch) of this plant on natural nests of A. cephalotes, in Cali, Colombia. Three treatments were randomly assigned to 30 nests: 1) green mulch of T. diversifolia, 2) green mulch of Miconia sp., Ruiz & Pav. and 3) unmulched control. Every 2 wk for 6 mo, the surface of the nests was completely covered with leaves. Physical and chemical parameters of nest soil were assessed before the first and after the last application of the mulch. Ant foraging in T. diversifolia-treated nests decreased by 60% after the initial applications of the mulch, while nest surface area decreased by 40%. When the nests covered with T. diversifolia were opened, it was observed that the superficial fungus chambers had been relocated at a greater depth. In addition, microbial activity and soil pH increased by 84% and 12%, respectively, in nests covered with plant residues. In conclusion, the continued use of T. diversifolia mulch reduces foraging activity and negatively affects the internal conditions of the colonies, thereby inducing the ants to relocate the fungus chambers within the nests.

Effect of mulches and nutrient levels on growth, nutrient uptake and productivity of cauliflower in mid hills of Himachal Pradesh

Field study on the effect of mulches and nutrient levels on weed infestation, growth, nutrient uptake and productivity of cauliflower (Brassica oleracea var. botrytis L.) was conducted during 2009–10 and 2010–11 in mid hills of Himachal Pradesh. Twelve treatment comprising combinations of four mulches, viz. black plastic mulch (BP), grass mulch (GM), pine needles mulch (PN), unmulched control (UM) and three levels of nutrients, i.e. F1(125% of recommended dose of NPK), F2(100% recommended dose of NPK) and F3(75% of recommended dose of NPK) were tried in factorial randomized block design. Results revealed that mulches effectively checked weed infestation, plant growth and cauliflower productivity were significantly influenced by mulches and nutrient levels. Black plastic mulch and 125% NPK together promoted plant and root growth, nutrient uptake, curd quality and yield of cauliflower. Treatment combination BPF1 recorded 88.7% higher productivity (head yield 266.8 q ha−1) closely followed by BPF2 (83.6%, 259.6 q ha−1) over unmulched control with 75% NPK (UMF3).

Effect of plant spacing and organic mulch on growth, yield and quality of natural sweetener plant Stevia and soil fertility in western Himalayas

The use of leaf mulch as a soil cover is effective in improving yield and soil fertility. The field experiment was conducted during 2010 and 2011 to study the effect of plant spacing (30 cm × 30 cm and 45 cm × 30 cm) and four mulches {pine needles (Pinus roxburghii), poplar leaf (Populus deltoides), silver oak (Grevillea robusta) tree leaf mulch and unmulched control} on growth, yield, quality of stevia and soil fertility. Weed count and dry weed weight was not affected by spacing levels during August and at the time of harvest, whereas, in unmulched plots it was significantly higher than mulched plots. Dry leaf yield, total dry biomass and leaf area index (LAI) were significantly higher in 30 cm × 30 cm spacing level and poplar leaf mulch. All the mulched plots significantly increased organic carbon (OC), available nitrogen (N), phosphorus (P) and potassium (K), bacterial and fungal population compared to unmulched plots. Rebaudioside-A content was higher in plots mulched with poplar leaves. Steviol glycosides were not significantly affected by different treatments. Soil biological activities were also enhanced by tree leaf mulches. Leaf mulch enhanced microbial biomass, relative to non-mulched soils, likely via improving C and water availability for soil microbes.

Preparation, properties and field application of biodegradable and phosphorus-release films based on fermentation residue

Mulch films are used in agricultural application mainly to produce high-quality crops. Based on Penicillium chrysogenum mycelium or on citric acid fermentation residue, biodegradable films with the function of soil temperature preservation, moisture maintenance and controlled fertilizer release of P were manufactured in this work to avoid waste of bioresources and plastic film pollution. They had been later used as suitable alternative to low density polyethylene (LDPE) films for cotton and maize production. Mechanical properties, water vapor permeability and thermal tests of films were measured in the laboratory before application. Their weight loss, microorganism growth on their surface and soil microclimate were also investigated during field application to evaluate their biodegradability. Only small cracks emerged in the structure of biodegradable films after four weeks in contact with the soil. The loss weight of the two films could reach about 40% and 21%, respectively after 90 days of application. The study also showed that biodegradable films demonstrated soil temperature preservation with 5–7 °C higher than un-mulched control and comparable function of moisture maintenance with commercial films after application.

Effect of Maize Stover Application as Soil Mulch on Yield of Arabica coffee (Coffee arabica L., Rubiaceae) at Western Hararghe Zone, Eastern Ethiopia

<p>An experiment was conducted during the dry seasons in western Hararghe Zone, Eastern Ethiopia at the Haramaya University Chiro Campus to determine the effect of maize stover as soil mulch on yield of Arabica coffee. Five levels of maize stover as soil mulch at a rate of: 0t/ha, 2t/ha, 4t/ha, 6t/ha and 8t/ha were applied in randomized complete block design with four replications from 2008 to 2011. Yield data was recorded during specific phenological stage of the plant. Result from the analysis of variance from the application of maize stover as soil mulch over years showed the presence of significant difference among treatments on bean yield of Arabica coffee. The highest bean yield (1070 kg/ha) and the lowest bean yield (520 kg/ha) were noted at 8 tons/ha and 0 ton/ha, respectively. Similarly, the pooled analysis of variance over seasons corroborated that the effect of maize stover as a soil mulch at a rate of 6t/ha and 8t/ha showed the presence of no significant difference on bean yield of coffee (p<0.05). The result of the present study also elucidated that, the unmulched control plots had the lowest coffee bean yield. While application of 8 tons/ha of maize stover as a soil mulch significantly increased coffee yield both in 2010 and 2011 cropping seasons. Therefore, on the basis of these results, it can be concluded that applying maize stover as soil mulch during the dry seasons at west Hararghe can help to sustain Arabica coffee production. Thus, it is recommended that application of 8tons/ha maize stover as soil mulch can significantly increase the yield of Arabica coffee and sustains its productivity over years.</p>

Role of Organic Mulching on Soil Properties of Alfisol in Rainfed Maize

Field experiment was conducted in Regional Research Station, Paiyur to asses the effect of organic mulching on soil physical properties, nutrient availability pattern and microbial population. The treatments included maize straw at 5 and10 t ha-1, sugarcane trash at 5 and10 t ha-1, raw coirpith at 5 and10 t ha-1 and dried weeds at 5 and10 t ha-1 and unmulched control, which were replicated thrice in Randomized Block Design. In maize, application of raw coir pith at 10 t ha-1 had reduced the bulk density and all the physical properties. Application of dried weed mulch at 10 t ha-1 (T9) recorded highest water holding capacity. Dried weed mulch at 10 t ha-1 recorded higher available N, P and K while raw coirpith at 10 t ha-1 (T7) increased the bacteria and fungal populations. Overall, mulches has great agro- ecological potential and they typically conserve the soil, improve the soil ecology, stabilize and improve soil properties.

Effects of different organic mulches on the soil surface arthropod community and weeds in snapdragon

Cultural control practices, including the use of cover crops and mulches, are convenient non-chemical methods for managing some insect pests and weeds. Several different types of organic mulches were evaluated for their effects on soil surface arthropods, weeds, and mortality of snapdragon plants in the autumn of both 2007 and 2008 near Citra, Florida, USA. In both seasons, five treatments were compared: cowpea mulch, sunn hemp mulch, sorghum-sudangrass mulch, pine bark nuggets, and an unmulched control. Mulches were applied around snapdragon plants in small plots, and treatments arranged in a randomized complete block design with five replications. Arthropod groups sampled using pitfall and board traps varied in their responses to treatments. The numbers of Formicidae, Cicadellidae, Orthoptera, and small-bodied plant-feeders (aphids, whiteflies, and thrips) were higher in control or cowpea plots than several of the other mulch treatment plots, possibly because weed levels were higher in control and cowpea plots. Collembola, Diptera, Araneae, and Coleoptera did not differ among treatments in either season. Board traps were effective for assessing Gryllidae and some beetles in 2007, when both groups were more abundant in the control and cowpea mulch plots than in the pine bark nugget plots, but in 2008 catches were not affected by treatment. Predatory insects were not consistently affected by mulches. Buckeye caterpillars feeding on the plants were not affected by the treatments and caused 28% mortality to snapdragon plants in 2007 and 27% mortality in 2008.