Crop Mulch Research Articles

Comparison of Organic and Inorganic Mulching for Weed Suppression in Wheat under Rain-Fed Conditions of Haripur, Pakistan

Weeds pose a great threat to crop production subsequently distressing the equilibrium of agro-ecological systems globally. Instead of relying on chemical weed control, there is a dire need to explore alternative eco-friendly agricultural practices for weed suppression and sustainable wheat production. Mulching being eco-friendly could potentially serve the purpose towards weed suppression organically. To check the usefulness of mulching, two-year studies were conducted under field conditions in Haripur, Pakistan, during 2014 and 2015 to elucidate the response of various mulching materials for weed control in wheat. Six mulch material treatments were used along with Buctril super (used as check) at the rate of 1.235 L ha−1 to control the most problematic weed species of wheat in Pakistan. Experiments were designed under randomized complete block design with four repeats. The analysis of data revealed a significant decrease in weed density, relative weed density, fresh and dry plant biomass at 25, 50 and 75 days after sowing (DAS) where Buctril super at 1.235 L ha−1 and mulch of black plastic were used followed by sugarcane bagasse and dry leaves of mulberry, as compared with control (untreated). Higher density of weed, relative weed density, fresh and dry plant biomass were observed in test weed species of wheat where lentil was applied with wheat and dry leaves of mulberry were incorporated. Net economic benefits in the form of benefit cost ratio (2.55) were higher where grass clippings were applied followed by sugarcane bagasse (2.43), mulberry leaves (2.49), while the lowest net economic benefits (1.72) were obtained when lentil (grown as live mulch crop) with wheat was intercropped. It was concluded from the study that sugarcane bagasse and grass clippings could be a source to control weeds in the wheat with a minimum cost of production at Haripur, Pakistan, and similar agro-climatic environment.

Variation in Postharvest Quality Attributes of Fresh Cowpea (Vigna unguiculata L.) Beans Harvested from Different Crop Mulching Regime

Background: Present study, aimed to assess effect of organic and inorganic crop mulching on physical, physiological and biochemical quality of fresh cowpea beans.Methods: Cowpea (cv. Kashi Kanchan bush-type) was grown during two consecutive seasons from April 2018 to July 2019 under four different mulching treatments. Mulching treatments included no mulch; wheat straw mulch (organic mulch); black mulch and silver mulch. Black and silver mulches were made of 25 microns LDPE sheet. Cowpea was grown as per standard agronomic practices and physical, biochemical and postharvest quality parameters of beans were evaluated.Result: Results indicated that bean length (28.7cm) was highest under silver mulch whereas bean thickness (9.10mm), width (9.29mm) and 100 bean weight (1094.5g) were highest under organic mulch. Likewise, protein content (28.63%), total phenolic content (17.0µg GAE/100g) and total antioxidant activity (46.84µmol trolox equiv./100g) were found highest in beans produced under organic mulch. Overall results demonstrated that crop mulching could be used for enhancing the antioxidants, phenolic content of cowpea beans.

Strip planted mechanical seeding of mustard and mungbean with crop residue retention is more profitable than conventional practice

Smallholder agriculture of the Asian continent faces a significant challenge of declining soil productivity and an acute shortage of ag-ricultural labor. Reduced tillage and crop residue mulch application is an integrated approach to preserving soil health and addressing the labor crisis to maintain farm sustainability. We undertook this study to evaluate the effect of strip planting and increased residue mulching on mustard and mungbean's productivity and profitability in northern Bangladesh during 2015 and 2016. Mustard cv. BARI Sharisha 14 and mungbean cv. BARI Mungbean 6 was grown follow-ing (i) Conventionally Tilled broadcasting method (CT) and (ii) Strip Planted line seeding (SP) with two levels of crop mulch (i) no-mulch and (ii) 50% mulch. The CT was done by a two-wheel tractor with four plowings and cross plowing followed by leveling. In SP, single tillage, seeding, fertigation, and field leveling were done simultane-ously by a Versatile Multi-crop Planter machine. Results reveal that mechanized seeding of mustard and mungbean in SP with 50% resi-due mulching fetched 62% higher profit than broadcasted CT with-out residue through producing 24% higher seed yield. This practice reduced the land preparation costs by 68%, in association with re-ducing the labor and fuel requirements by 30%. Hence, it could be concluded that the mechanized seeding of mustard and mungbean with the retention of 50% of crop residue is profitable to the con-ventionally broadcasted seeding process.

Influence of Short-term Maize–Green Manure Cover Crop Rotations on Germinable Weed Seed Bank under Conservation Agriculture

The effects of one- and two-year maize-cover crop rotations on weed seed bank density and species composition were evaluated in fields at the University of Zimbabwe (UZ) and the International Maize and Wheat Improvement Center (CIMMYT, Harare) between 2014 and 2017. Nine cover crops were rotated, and maize and weed seed bank analyses were done using the seedling emergence method. Maize was used as the control. The results indicated that weed seed density was not significantly (p > 0.05) affected by cover crop mulch type across the seasons. There was a significant (p < 0.05) decline in weed density in the second maize phase of the rotation in UZ Field A. Bidens pilosa, Galinsoga parviflora, Amaranthus hybridus and Eleusine indica were the dominant weeds. B. pilosa density significantly decreased in the second season in UZ Field A but did not vary significantly among cover crops. Significant changes in weed species richness, evenness, and diversity were observed only in the second phase of the rotation in UZ Field A. The results suggest that maize-cover crop rotations could be effective in reducing seed bank size in the short term but have no short-term effect on weed species community composition.

Nitrogen dynamics in grain cropping systems integrating multiple ecologically based management strategies

AbstractNitrogen (N) management is a critical agronomic challenge, as N losses are a source of pollution affecting both waterways and air quality and a potential economic loss for farmers. One approach to N conservation is through ecologically based agricultural systems that reduce tillage and incorporate cover crops. However, these systems exhibit considerable complexity resulting in potential agronomic trade‐offs. To address these concerns, four crop management systems were implemented within an organically managed corn–soy–winter grain crop rotation. These systems varied in tillage frequency and intensity, cover crop species selection, cover crop termination and establishment methods, fertilizer management, and cash crop season length. We used field measurements to investigate the impact of each system on N pools and to reveal the strengths and weaknesses of each system in addressing N provisioning services, with a focus on the supply and retention of N before and after the corn phase of the rotation. All systems had greater estimated N inputs (via manure and N‐fixation) than outputs (via crop harvest) at the end of the three‐year rotation, demonstrating the importance of prioritizing N retention in cover crops. Interactions among system components were important drivers of temporal N dynamics; cover crop species traits and timing of manure application contributed to differences in total aboveground plant biomass N among systems. For example, one cropping system which included a no‐till corn planting into a rolled cover crop mulch had soil inorganic N availability that was asynchronous with the N needs of the corn crop even though it received the same amount of N inputs as the other systems. In general, neither interseeding cover crop mixtures nor reducing tillage resulted in marked N benefits at the system level; we did not observe improved N retention from either practice in these systems, and there was no increase in N uptake by corn. What did clearly emerge from this experiment is the importance of managing for synchrony between soil inorganic N availability and cash crop N demand as influenced by the N retention capacity of cover crops and the timing of N mineralization due to tillage.

Efficacy of rice straw mulch for the sustainable production and insect pest management in okra (Abelmoschus esculentus)

With an aim to utilize rice straw for crop mulching purpose and prevent environmental damage caused due to its burning, the efficacy of rice straw mulching was compared with the standard practice of silver colored polyethylene mulch and without mulch in okra (Abelmoschus esculentus (L.) Moench) for the crop growth, yield and for the reduction of insect pest population. The trials were performed during the rabi season with two sprays each of neem (Agroneem®@ 2 ml/l), imidacloprid (Confidor®@ 0.5 ml/l) and their combination. Plant growth and yield was significantly higher in silver mulch and straw mulch compared to the control. The yield of okra was maximum in silver colored polythene mulch along with the application of insecticide imidacloprid. The yield were 23.89, 16.08 and 15.80 t/ha respectively during the years, 2015-16, 2016-17 and 2017-18. The yield observed in straw mulch was slightly lower than silver colored polythene mulch, but higher than control. The straw mulch was found at par with silver colored polythene mulch in reducing population of sap sucking insect, pests, aphids, thrips, leafhoppers and whiteflies. Among the treatments, spray of imidacloprid (@ 0.5 ml/l) was found best for reducing pest population. The results indicated the utility of rice straw mulching as an organic option for the okra cultivation, which is otherwise burnt every year creating huge environmental problem in India

Better Together? Combining Cover Crop Mulches, Organic Herbicides, and Weed Seed Biological Control in Reduced-Tillage Systems.

Organic vegetable farmers rely heavily on labor-intensive tillage for weed management, which adversely affects soil health and harms beneficial insects that consume crop pests and weed seeds. Using cover crop residues as a weed-suppressive mulch enables some reduction in tillage, and combining this tool with recently developed organic herbicides may further enhance weed suppression in vegetable production. However, organic herbicides may also adversely affect beneficial insects, and their nontarget effects are unknown. Here, we examine the combined impacts of cultural and chemical tools on weed cover while monitoring activity of beneficial epigeal insects and measuring rates of weed seed biological control to assess potential nontarget effects of organic herbicides. In a 2-yr experiment, we compared three cover crop mulch treatments and three organic herbicide treatments (capric/caprylic acid, corn gluten meal, and herbicide-free) in a reduced-tillage system. Organic herbicides led to no reductions in beneficial insect activity nor weed seed biocontrol. In both years, capric/caprylic acid herbicide and cover crop mulches reduced weed pressure relative to a fallow control treatment, whereas corn gluten meal had no effect. In year 2, a combination of cover crop mulch with organic herbicide had the greatest weed suppression relative to the fallow control. Integrated weed management is a perpetual challenge, but our results suggest that organic herbicides used in concert with cover crop mulch may enhance weed control and reduce the need for tillage, with limited collateral damage to natural enemies.

The potential of alfisols developed on different parent materials in two agro-ecological zones for oil palm production in Nigeria

The excessive use and lack of information on the properties and potentials of agricultural land have led to misuse, mismanagement, soil erosion and loss of soil quality in the tropics. Land suitability evaluation is a tool for assessing the potential of land for the cultivation of specific crops. The study was conducted during 2018 and 2019 on soils of two agro-ecological zones of dry upland rainforest (Ado-Ekiti) and southern guinea savanna (Kabba) of Nigeria. They were mapped, characterized and classified for their potential to support the cultivation of oil palm. Seven mapping units were delineated at Ado-Ekiti (labeled AA to AG) and nine units at Kabba (labeled KA to KI). Based on the principle of matching land qualities and climatic requirements of crop to the characteristics of the land, the suitability classification of the soils mapping units was developed. Mapping units KA, KD, KG, KH, KI, AA, AB, AD, AE and AF have index of actual productivity (IPC) lower than 50% therefore they were rated as currently marginally suitable (S3) for oil palm production. KB, KC, KE, KF, and AC were currently not suitable (N1) while AG was permanently not suitable. The major limitations to oil palm production at both sites were rainfall, poor soil drainage condition in some portion and soil fertility. Fertility is a limitation that can be improved with appropriate post-harvest crop residue management and mulching, use of organic manure and biosolids, legumes in crop rotations; judicious use of inorganic fertilizer and integration of fertilizer with manures these will raise the productivity of mapping units KB, KF, KG, KH and AA, AB, AC, AD to AF to class S2; moderately suitable for oil palm production.

Weed dynamics as affected by practices and straw mulches in chickpea

A two year field experiment entitled “Effect of weed control practices alone and in combination with crop mulch on weed dynamics, yield and economics of chickpea” was conducted at Live Stock Farm, Department of Agronomy, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur during Rabi 2018-2019 and 2019-2020. The 16 treatments comprising of four weed control practices viz. Pendimethalin (38.7% CS) 1 kg a.i. /ha as PPI, Hand Weeding at 30 DAS, Hand Hoeing at 30 DAS and Control (No weed control) as a main plot treatments and four crop mulches i.e. Wheat straw (5 t/ha), Paddy straw (5 t/ha), Soybean straw (5 t/ha) and Control (No mulch) were assigned in sub-plot treatments and these were laidout in a split plot design with three replications. It is evident from the data Cichorium intybus (31.95%), Medicago truncatula (21.82%) and Melilotus indica (20.52%) were rampant weeds in chickpea. Hand hoeing at 30 DAS caused marginal reduction in density and dry weight of weeds over weedy check. However, hand weeding done at 30 DAS in chickpea curbed the density and dry weight of weeds to the maximum extent followed by pendimethalin 1 kg /ha as PPI and attained the higher values of weed control efficiency (69.68 and 52.12% respectively) compared to hand hoeing (42.23%) and weedy check plots (0.00%). Similarly, application of paddy straw (5 t/ha) reduced the density and dry weight of weeds appreciably and attained higher weed control efficiency (61.34%) followed by wheat straw (53.04%) against soybean straw which reduced weed biomass to the tune 32.62 % only. The chickpea yield was minimum (0.87 t/ha) in control plots, which was increased markedly under different weed control practices and crop mulches. Hand weeding done at 30 DAS produced significantly higher seed yield (1.67 t/ha) being at par to pendimethalin 1kg /ha (1.49 t/ha) than one hand hoeing (1.27 t/ha) and control plots (0.87 t/ha). The seed yield was significantly higher (1.55 t/ha) under paddy straw mulch (5 t/ha) followed by wheat straw mulch (1.40 t/ha) in comparison to no straw mulch plots (1.10 t/ha) and soybean straw mulch (1.23 t/ha).

Bioplastic Film from Black Soldier Fly Prepupae Proteins Used as Mulch: Preliminary Results

A protein-based film (PBF), obtained from black soldier fly prepupae proteins, was assessed for its agronomic performance as mulch. PBF was investigated in a potting experiment and compared with Mater-Bi (MB), polyethylene (PE) and bare soil. During the experiment, degraded surface area, weight and thickness of the film, water evaporated from the pot, and the soil microbiological content (SMC) were recorded. In addition, films were buried to assess their biodegradability and impact on SMC. During the mulching process, the PBF showed a significant degradation. In terms of evaporated water, the PBF performed similarly to MB and worse than PE. Regarding SMC, film of any nature caused an increase in the Clostridia spp. and a decrease of total mesophilic aerobic bacteria and fungi contents. When buried, only PBF recorded a faster biodegradability, showing a reduction of surface area, thickness and weight. PBF and MB highlighted a significant increase in contents of Clostridia spp., mesophilic aerobic bacteria and fungi. Our results reported, for the first time, the valorization of black soldier fly (BSF) prepupae proteins as a biodegradable film for mulching purposes. However, further study is needed to reduce the PBF biodegradability and allow it to be used for the most important mulched crops.

Cover crops during transition to no-till maintain yield and enhance soil fertility in intensive agro-ecosystems

• No-till (NT) with cover crops (CCs) maintains yield of wheat, maize and soybean. • NT-CCs increased SOM from 20% to 30% compared to CT in the 0-30 cm soil layer. • NT-CCs increased STN from 21% to 28% compared to CT in the 0-30 cm soil layer. • Replacing CT with NT and winter CCs enhances soil fertility in the long-term. Introducing no-till and cover crops in arable agro-ecosystems leads to the restoration of soil fertility, through the increase of soil organic matter (SOM), soil total nitrogen (STN), and available phosphorus (P), therefore maintaining or enhancing crop yield and reducing costs. Although the effects of those practices have been widely examined, many studies show conflicting results and little is known about the combined effects of no-till (NT) and cover crops (CCs) under intensive arable cropland in the Po Valley (Northern Italy). The objectives of this study were: (i) to evaluate if NT management coupled with CCs negatively affects yields during the transition period and how yields evolve; (ii) to assess SOM, STN, and P dynamics in the 60-cm soil depth layer; and (iii) to evaluate the effects of different types of winter cover crops on yield and soil parameters. A six-year field experiment was established in Piacenza, on a silty-clay soil under temperate climate conditions. The crop sequence was: winter wheat, maize, maize, soybean, winter wheat, and maize. The four experimental treatments were: (1) conventional tillage (CT) as control; (2) NT with CC of rye (NT-R); (3) NT with CC of hairy vetch (NT-V); and (4) NT with a mixture of CCs (rye, hairy vetch, crimson clover, Italian rye-grass and radish) [NT-M]). Dry biomass yield of CCs ranged between 2.2 and 3.1 Mg ha −1 for rye; 1.9 and 3.0 Mg ha −1 for hairy vetch; and 1.9 and 3.2 Mg ha −1 for mixture. In the present study, yields of winter wheat, maize, and soybean were generally not reduced with NT-CCs since the first year after conversion. The different composition and thickness of cover crop mulch showed an opposite yield response to rainfall pattern: under NT-R, a negative correlation was observed between grain yield and rainfall, while under NT-V this correlation was positive. After six years, SOM and STN concentrations in the 0-30 cm soil layer increased in NT-CCs. SOM concentration was +30%, +23% and +20% higher than CT for NT-R, NT-M and NT-V, respectively. STN was +28% higher under NT-R and NT-V, and +21% higher under NT-M, than CT. Conversely, P concentration was not influenced by the NT-CCs system, although we observed a tendency to increase under NT-V. In the 30-60 cm soil, layer, the tillage systems did not affect SOM and STN. We concluded that introducing NT with winter CCs into intensive arable agricultural systems is an effective strategy for enhancing soil fertility in fine-textured soils under temperate climates, without penalizing yields.

Soil functions are affected by transition from conventional to organic mulch-based cropping system

Soil ecosystem services depend on soil properties and their interactions, which are mostly influenced by soil use and management. The main objective of the present study was to evaluate, through a multidisciplinary approach, the effect of different cropping systems on food provisioning, soil chemical features, size and structure of soil microbial community, soil invertebrate biodiversity and habitat provision (trophic interactions). The systems were: conventional integrated (INT); traditional organic with cover crops and conventional tillage (ORG); and organic coupled with conservation agriculture (cover crop mulching and no-tillage, ORG+). During 2016, we conducted soil and field samplings and collected data relative to the crop yield, C and N content in the agroecosystem, chemical and microbial soil properties and soil invertebrate abundance and trophic interactions. The INT system showed the highest crop yield (similar to ORG and three-fold higher than ORG+). Nevertheless, the INT system showed the greatest amount of N lost with drainage water (six-fold higher than the other systems), the lowest soil total PLFA abundance (around two-fold lower than ORG and ORG+ in the Ap1 horizon of soil). Additionally, INT system was characterized by the lowest invertebrate biodiversity (e.g., two-fold and ten-fold lower than ORG and ORG+ respectively for ground-dwelling predator abundance). By contrast, the ORG+ system had the lowest crop yield, but it showed the highest soil total organic C concentration and microbial biomass in the Ap1 horizon, supported higher invertebrate biodiversity and a slightly wider prey-spectrum for ground beetle predators. The ORG system had an intermediate behaviour between INT and ORG+. The results of this study demonstrate that, despite the reduction of crop yield, the conversion from INT to ORG or ORG+ possibly enhances important soil functions like nutrient cycling and storage, biodiversity and habitat provisioning. However, management optimization for improving crop yield would be required to make ORG+ a viable system.

Use of leguminous cover crop and banana bio-mat mulch for quality production of guava cv. Sardar (L-49)

Use of leguminous cover crop and banana bio-mat mulch for quality production of guava cv. Sardar (L-49)

Decomposition of cover crop mulch and weed control under a no-till system for organic maize

The decomposition dynamics of cover crop mulch influence the nutrient supply of successor crops and weed suppression. This is even more relevant in organic production systems, due to their limited use of chemical fertilizers and herbicides. As such, the aim of this study was to quantify biomass production, model the decomposition and N, P and K release of the mulch of different cover crops, and assess the weed suppression of cover crops in the form of mulch and in consortium with organic maize. A randomized block design was used, with a 7x2 factorial scheme (7 cover crop management strategies and 2 cropping systems - maize in monoculture and intercropped with jack bean) and 4 replicates. The management practices that produced the most biomass were white lupine intercropped with black oat and the white lupine, black oat and sunflower monocultures. The use of cover crops did not differ from manual weeding in terms of weed biomass, but did affect the relative importance (RI) of nutgrass. Additionally, maize intercropped with jack bean reduced weed biomass in subsequent crop growth stages.

Crop Mulches for Increased Weed Control and Rice Productivity

A study was conducted to determine the influence of mulches of rice (R), maize (Mz), mucuna (Mc) and cymbopogon (C) on weed growth and rice yield. Twelve mulch treatments included MzRC, RMcC, MzMC, MzRMc, MzRC + one hand rogueing of weeds (hr), RMcC + hr, MzMcC + hr, MzRMc + hr, MzRC + one hand hoeing of weeds (hh), RMcC + hh, MzMcC + hh and MzRMc + hh, 2hh, 3hh, Butanil +1hh and a weedy check in a randomised complete block design (RCBD) with three replicates. The study was conducted both on-station and on-farm (2014). CMcRMz species were each planted in 24 plots under a RCBD replicated thrice and 3 crops uprooted from the plots were combined in equal proportions of different stover into four mulches (MzRC, RMcC, MzMcC & MzRMc). The experimental site was ploughed, divided into 48 plots under RCBD replicated thrice and the mixed mulches were applied (10-12.Mt ha-1) to 12 plots at planting. Higher rice growth was recorded under MzMc than RC mulches with or without a post mulch weed control. RC based mulches most effectively reduced weed density and biomass followed by MzMc mulches. 2hh and MzRMc mulch + 1hr produced similar rice yield but lower rice yield was under RMcC and Butanil + 1hh. Rice growth and tiller development reduced under the weedy check giving zero yields. The highest Striga was under Butanil + 1hh (8 Striga), followed by 3hh and 2hh (3 & 2 Striga). No Striga was recorded under cymbopogon mulches and weedy check. The highest returns on investment (ROI) were under 2hh (0.52 & 0.43) at the two sites and MzRMc + hr recorded high ROI (0.47) on station, similar to 3hh on-farm. Maize, rice, cymbopogon and mucuna have high potential to produce bio-herbicides with high rice yields.

Cover Crop Effectiveness Varies in Cover Crop-Based Rotational Tillage Organic Soybean Systems Depending on Species and Environment

Organic farming relies heavily on tillage for weed management, however, intensive soil disturbance can have detrimental impacts on soil quality. Cover crop-based rotational tillage (CCBRT), a practice that reduces the need for tillage and cultivation through the creation of cover crop mulches, has emerged as an alternative weed management practice in organic cropping systems. In this study, CCBRT systems using cereal rye and triticale grain species are evaluated with organic soybean directly seeded into a rolled cover crop. Cover crop biomass, weed biomass, and soybean yields were evaluated to assess the effects of cereal rye and winter triticale cover crops on weed suppression and yields. From 2016 to 2018, trials were conducted at six locations in Wisconsin, USA, and Southern France. While cover crop biomass did not differ among the cereal grain species tested, the use of cereal rye as the cover crop resulted in higher soybean yields (2.7 t ha−1 vs. 2.2 t ha−1) and greater weed suppression, both at soybean emergence (231 vs. 577 kg ha−1 of weed biomass) and just prior to soybean harvest (1178 vs. 1545 kg ha−1). On four out of six sites, cover crop biomass was lower than the reported optimal (<8000 kg ha−1) needed to suppress weeds throughout soybean season. Environmental conditions, in tandem with agronomic decisions (e.g., seeding dates, cultivar, planters, etc.), influenced the ability of the cover crop to suppress weeds regardless of the species used. In a changing climate, future research should focus on establishing flexible decision support tools based on multi-tactic cover crop management to ensure more consistent results with respect to cover crop growth, weed suppression, and crop yields.

Influence of drip irrigation and polyethylene mulch on growth, yield and water productivity of tomato (Solanum lycopersicum) and brinjal (Solanum melongena) cultivars in eastern plains

A field experiment was carried out during 2014-15, 2015-16 and 2016-17 in silty clay loam soil of Bihar, to study the effect of drip irrigation and black polyethylene mulch compared with furrow irrigation on growth, yield and water productivity of tomato (Solanum lycopersicum L.) and brinjal (Solanum melongena L.). Drip irrigation influenced the growth and yield characters of both vegetable crop as compared to furrow method of irrigation. Further, drip irrigation significantly increased the fruit yield of tomato and brinjal by 26.9 and 40 percent, respectively. Mulching also had a positive effect on yield attributing characters, viz. days taken to flowering, average single fruit weight and number of fruits/plant of both tomato and brinjal. Use of black polyethylene mulch gave 38.6 and 44.6% higher yield of tomato and brinjal compared with unmulched treatments (35 and 26 t/ha, respectively).Tomato variety Swarna Sampada and brinjal variety Swarna Shobha performed better over other varieties irrespective of drip and mulch. Drip irrigation in combination with black polyethylene mulch significantly increased the plant height, dry matter production, number of fruits/plant, fruit weight and finally raised the tomato yield and brinjal yield to 54.4 and 44.45 t/ha with 34% water saving. The average water productivity (17.0 and 13.9 kg/m3) of tomato and brinjal was also maximum in drip irrigated mulched crops.

Cover Crop Termination Treatment Impacts Weed Suppression Potential

AbstractWeed management in tobacco (Nicotiana tabacumL.) is accomplished primarily with soil-residual herbicides, cultivation, and hand removal. Management practices that reduce weed emergence, like reduced tillage and cover crop mulches, may improve weed management efficacy. Depending on cover-cropping goals, growers face trade-offs in species selection and management priorities—producing weed-suppressive mulches may lead to transplanting difficulties and soil-residual herbicide interception. Managing more complex cover crop mixtures may result in different challenges. We established on-farm trials across 4 site-years to study impacts of cover crop composition [wheat (Triticum aestivumL.) monoculture or mixture], termination treatment (early or late chemical termination or removing aboveground biomass), and soil-residual herbicides on weed density and biomass. The cover crop mixture contained cereal rye (Secale cerealeL.), crimson clover (Trifolium incarnatumL.), and hairy vetch (Vicia villosaRoth.), with canola (Brassica napusL.) at 1 site-year. The mixture typically produced more biomass than monoculture wheat, although composition had few impacts on weed density or biomass. With residual herbicides, termination treatment had few impacts on weed density, suggesting that residues did not adversely affect herbicide efficacy. Without residual herbicides, early-season weed density was often higher following the late-terminated cover crop compared with other termination treatments, though midseason weed density was typically lower. When termination treatment affected final weed biomass, it was lower following late termination, with one exception—crop establishment was reduced at 1 site-year, leading to reduced weed–crop competition and greater weed biomass. Our results suggest that growers can use mixtures and, if well-timed to a rainfall event for incorporation, still effectively use soil-residual herbicides to maintain adequate weed control in tobacco regardless of how the cover crop is managed. Later termination, resulting in more residue, may lead to less weed biomass accumulation in the absence of herbicide use.

Effects of Integrated Polyethylene and Cover Crop Mulch, Conservation Tillage, and Herbicide Application on Weed Control, Yield, and Economic Returns in Watermelon

AbstractA 3-yr watermelon experiment was established in fall 2013 to evaluate cover crop, polyethylene mulch, tillage, and herbicide application components for weed control, yield, and profitability. Conservation tillage, either with a cereal rye cover crop alone or integrated with polyethylene mulch, was compared to the standard industry practice of conventional tillage with bedded polyethylene mulch. The study also used a non-bedded conventional tillage system without polyethylene to determine polyethylene and cover crop residue effects. Within each of the four systems, herbicide treatments comprised halosulfuron applied (1) at 26.3 g ai ha–1PRE, (2) at 26.3 g ai ha–1POST, or (3) sequentially at 26.3 g ai ha–1PRE and POST. Each system also had a nontreated control. In addition, clethodim was applied in all plots twice POST at 140 g ai ha–1, except for nontreated in each system. In 2014, polyethylene or cereal rye cover crop effectively controlled tall morningglory, coffee senna, and carpetweed early season in nontreated plots, whereas the integration of the two was effective at controlling common purslane. Tall morningglory and purslane control was insufficient late season regardless of production system and herbicide application. In 2015, polyethylene effectively controlled cutleaf eveningprimrose, sicklepod, and arrowleaf sida early season in nontreated plots. Yellow nutsedge control was insufficient late season regardless of production system and herbicide application. Utilizing sequential halosulfuron applications did not increase weed control over PRE or POST alone in all years. Polyethylene use resulted in yields higher than systems without in all years. Across all 3 yr, net returns were highest for polyethylene mulch systems. The results of this experiment underscore the need for more progress in developing integrated conservation systems for watermelon production. Effective herbicides, low-disturbance cultivation, and/or hand weeding are most likely the key to success in conservation specialty crop systems.

Investigating tarps to facilitate organic no-till cabbage production with high-residue cover crops

AbstractHigh-residue cover crops can facilitate organic no-till vegetable production when cover crop biomass production is sufficient to suppress weeds (>8000 kg ha−1), and cash crop growth is not limited by soil temperature, nutrient availability, or cover crop regrowth. In cool climates, however, both cover crop biomass production and soil temperature can be limiting for organic no-till. In addition, successful termination of cover crops can be a challenge, particularly when cover crops are grown as mixtures. We tested whether reusable plastic tarps, an increasingly popular tool for small-scale vegetable farmers, could be used to augment organic no-till cover crop termination and weed suppression. We no-till transplanted cabbage into a winter rye (Secale cereale L.)-hairy vetch (Vicia villosa Roth) cover crop mulch that was terminated with either a roller-crimper alone or a roller-crimper plus black or clear tarps. Tarps were applied for durations of 2, 4 and 5 weeks. Across tarp durations, black tarps increased the mean cabbage head weight by 58% compared with the no tarp treatment. This was likely due to a combination of improved weed suppression and nutrient availability. Although soil nutrients and biological activity were not directly measured, remaining cover crop mulch in the black tarp treatments was reduced by more than 1100 kg ha−1 when tarps were removed compared with clear and no tarp treatments. We interpret this as an indirect measurement of biological activity perhaps accelerated by lower daily soil temperature fluctuations and more constant volumetric water content under black tarps. The edges of both tarp types were held down, rather than buried, but moisture losses from the clear tarps were greater and this may have affected the efficacy of clear tarps. Plastic tarps effectively killed the vetch cover crop, whereas it readily regrew in the crimped but uncovered plots. However, emergence of large and smooth crabgrass (Digitaria spp.) appeared to be enhanced in the clear tarp treatment. Although this experiment was limited to a single site-year in New Hampshire, it shows that use of black tarps can overcome some of the obstacles to implementing cover crop-based no-till vegetable productions in northern climates.