No Mulch Research Articles

Plastic mulching enhances maize yield and water productivity by improving root characteristics, green leaf area, and photosynthesis for different cultivars in dryland regions

Uneven precipitation during the growing season and frequent seasonal droughts on the Loess Plateau in Northwest China adversely affect crop production and water use efficiency. While plastic mulching (PM) has been used to alleviate water stress, few studies have examined the traits maize cultivars need to adapt to the altered water environment under PM and achieve high yields. A two-year field experiment was conducted to assess the root characteristics and aboveground growth traits of three widely used high-yielding maize cultivars—Zhengdan 958 (ZD), Huanong 138 (HN), Heboshi 122 (HBS)—under no mulching (NM) and PM conditions. Among the three cultivars, HBS had the highest root system indices—root length density (RLD), root surface area density (RSD), and root biomass—in the topsoil (0–40 cm), followed by ZD and HN under both NM and PM conditions. Under NM, HBS_NM treatment exhibited strong water absorption, improving photosynthesis and yield, making it suitable for drought conditions. Under PM, topsoil moisture increased significantly, with root system indices increasing by 22.5–36.1 % for RLD, 30.2–36.1 % for RSD, and 25.2–36.5 % for root biomass across the cultivars compared to NM. While ZD_PM did not have the highest root system indices under PM, it exhibited higher green leaf area index (4.5–7.5 %), chlorophyll content (2.8–8.6 %), and photosynthetic rate (6.0–14.5 %), resulting in the highest aboveground biomass and yield among the treatments. These findings suggest ZD is better adapted to the enhanced soil moisture under PM. Future research should focus on breeding genotypes that thrive under PM conditions, emphasizing traits such as larger leaf areas and higher photosynthetic rates to boost crop productivity in rainfed areas.

Effects of Film Mulching on Soil Microbial Diversity and Community Structure in the Maize Root Zone under Drip Irrigation in Northwest China

Mulching is a widely used agricultural water conservation measure in the semiarid regions of Northwest China. In order to explore the response process of different film mulching methods to soil microorganisms, we characterized the effect of different film mulching methods on soil microbial diversity and community structure characteristics in the root zone of drip-irrigated maize during the heading and maturity stages using high-throughput sequencing of 16SrDNA and ITS amplicons combined with bioinformatics analysis. Full mulching (FM) was contrasted to controls of no mulching (NM) and half-mulching (HM), yielding an order of microbial diversity, abundance, and evenness scores of HM > FM > NM. The HM and FM treatments reduced the relative abundance of Proteobacteria and Actinobacteria (the most abundant bacteria) in the bacterial community structure but increased that of Acidobacteria and Chloroflexi. In the fungal community structure, HM decreased the abundance of Sordariomycetes but increased that of Eurotiomycetes (the most abundant fungi). The abundance and community structure of bacteria were significantly correlated with soil temperature and those of fungi with pH. HM improved network complexity and competitive relationships among bacteria, while FM increased the relationship between fungal groups and the symbiosis of fungal communities. HM significantly increased maize yield (20.37% and 6.01% above NM and FM, respectively). In summary, full mulching was more favorable than no mulching for soil microbial diversity and community structure composition, but soil microbial diversity and yield responded better to half-mulching. These results provide a background for improving the yield of drip-irrigated maize and protecting the microbial ecosystems of farmland soils.

Evaluating the Effects of Deficit Irrigation and Mulch Type on Yield and Yield Components of Onion in Fogera, Ethiopia

Water scarcity is a challenge for current irrigated agriculture globally. Under these circumstances, new on-farm irrigation management strategies should be established. An experiment was conducted at Fogera in 2021 to evaluate the effects of deficit irrigation (DI) and mulch type on onion yield and yield components. A factorial combination of three levels of DI (100%ETc, 75%ETc, and 50%ETc) and three mulch types No Mulch (NM), White Plastic Mulch (WPM), and Rice Straw Mulch (RSM)) were evaluated in RCBD with three replications. Monthly ETo, ETc, and irrigation scheduling were computed using CROPWAT 8.0 model. These studies showed that the onion yield and yield components were significantly affected by the main and the interaction effects. The maximum average plant heights (PH), leaf heights (LH), and number of leaves per plant (LNP) of 51.7 cm, 38.0cm, and 10.4 respectively, were recorded from 100%ETc whereas the minimum PH, LH, and LNP of 39.5 cm, 29.0cm, and 6.9 were recorded from 50%ETc treatment respectively. The highest average bulb weight (BW), bulb diameter (BD), and bulb height (BH) were 117.9gr, 6.4, and 5.7 cm recorded from 100%ETc treatment respectively. In contrast, the minimum average BW, BD, and BH were 79.9gr, 4.8, and 5.0cm recorded from 50%ETc respectively. The highest PH, LH, and LNP of onions were 51.9cm, 40.6cm, and 10.1 respectively recorded from RSM treatments. In contrast, the minimum PH, LH, and LNP of onions were 41.5cm, 31.1cm, and 7.5 respectively, recorded from WPM treatments. Similarly, the highest mean BW, BH, and BD 106.2gr, 5.8cm, and 6.0cm were obtained from the treatments of RSM respectively. In contrast, the lowest mean BW, BH, and BD 100.7gr, 5.0cm, and 5.3cm were obtained from NM treatments respectively. The interaction effects of DI and mulch showed that the onion yield at 100%ETc with RSM was 7.5% higher than that at 100%ETc with NM and 15.1% higher than the yield at 100%ETc with PM. The highest BW, BH, and BD of the onion 121.8 gr, 6.2, and 6.8 were obtained when the onions received 100%ETc and mulched with RS while the lowest average BW, BH, and BD of the onion were 77.3gr, 4.6cm and 4.1cm were obtained from 50%ETc with NM treatment combination. These results showed that RSM with 75%ETc improves onion yield and yield components.

A three-year record of CO2, CH4 and N2O emissions in maize fields influenced by mulching methods on the Loess Plateau, China

Exploring optimal mulching methods for maize production is critical to achieving a balance between maximizing yield and reducing negative environmental impacts in dryland agriculture. Therefore, a 3-yr field experiment was conducted to investigate the effects of three mulching methods—biodegradable plastic film mulching (BM), maize straw mulching (SM), and no mulching (NM)—on spring maize yield, greenhouse gas (GHGs) emissions (CO2, CH4, and N2O), soil factors, the net ecosystem GHG balance and greenhouse gas emission intensity (GHGI) on the Loess Plateau of China. The result showed indicated that CO2 and N2O are the primary sources of GHGs in dryland maize production. The yield of BM significantly increased 1.43–1.99 t ha−1 compared to NM, CO2 emissions (on average 32.83%) compared to the NM. And BM showed suitability for N2O emissions (3.7–11.2%). SM increased CO2 and N2O emissions (by 9.43–13.17% and 24.96–33.64%, respectively) compared to the NM. Structural equation model analysis showed that soil temperature was the most direct factor to affect GHGs. SM was the sink of net ecosystem GHGs, BM and NM were the source of net ecosystem GHGs. These results indicated that mulching emerges as a promising strategy for dryland agriculture. BM method can be used when the primary goal was to improve yield, while SM method is a better choice when the primary goal was to improve soil organic carbon sequestration and reduce net GHGs emissions. This study clarified the impacts of mulching methods on three GHGs emissions to provide information support for sustainable agriculture on the Loess Plateau.

Tarping and mulching effects on crop yields, profitability, and soil nutrients in a continuous no-till organic vegetable production system

Abstract Small-scale organic vegetable farms need strategies to overcome yield, labor, and economic challenges in transitioning to reduced and no-till practices. However, the production tradeoffs associated with different scale-appropriate management practices are not well documented for these operations. We evaluated crop yields, labor, profitability, and soil nutrients over four continuous years of management in Freeville, NY. Cabbage (Y1 and Y3) and winter squash (Y2 and Y4) were managed in permanent beds under four contrasting tillage systems: conventional rototilling to 20 cm depth (CT), shallow rototilling to 10 cm (ST), no-till (NT), and no-till with tarping (NTT), in which an impermeable, black polyethylene tarp was applied to the soil surface between crops. Within each tillage treatment, we compared three mulching systems: rye mulch (RM), compost mulch (CM), and no mulch (NM), where mulches were applied annually to each crop. Crop yields did not vary by tillage, except in RM, where yields were highest in CT and reduced in ST and NT over four years. Mulch treatments were a significant driver of crop yields. When compared to NM, RM reduced crop yields in the first two years and CM increased yields after the first year. Overall, RM systems had the lowest net returns and CM returns were equivalent to NM despite greater yields. No-till consistently required the greatest pre-harvest labor investment, up to two times greater than tilled systems with NM, and the lowest net returns. Labor requirements for NTT were greater than CT but up to 41% lower than NT, and profitability was equivalent to CT. Shallow tillage performed similar to CT across yield, labor, and profitability measures, except when combined with the use of RM. Compost mulching led to dramatic changes in soil properties after four years, including a 49% increase in total soil carbon, a 31% increase in total soil nitrogen, and a 497% increase in extractable phosphorus. Small farms adopting NT practices should: 1) consider the potential tradeoffs associated with annually applied organic mulches, and 2) integrate tarping to increase the profitability of NT over consecutive production years.

Studies on Sesbania, rice residue mulching and post emergence herbicides on weed growth and yield in unpuddled transplanted hybrid rice

AbstractWeeds are a major threat in unpuddled transplanted rice during rainy seasons. To manage weeds by using Sesbania residue green mulch, rice straw mulch and post emergence herbicides in an integrated way, an experiment was conducted in a split plot at Varanasi during the rainy season of 2017 and 2018. The experiment was taken with three mulching treatments in main plots, namely, no mulching (NM), cover crop of Sesbania aculeatea followed by its green residue mulch (SRGM) and rice straw mulch (RRM) in inter rows and five weed management treatments, namely, weedy, hand weeding twice (HWT), post emergence application of bispyribac 25 g a.i ha−1 (BP), penoxsulam 30 g a.i ha−1 (PX), bispyribac 25 g a.i ha−1 + pyrazosulfuron 20 g a.i ha−1 (BP + PS) in subplots replicated thrice. SRGM and RRM were noted to be successful in reducing density and biomass of grasses including Echinochloa colona and sedges and total weed (59% and 49%) biomass compared to NM under weedy conditions. Mulching, integrated with post emergence herbicides proved its potency in not only weed reduction but is also in yield enhancement.

Adaptability of agricultural soil microbial nutrient utilization regulates community assembly under mulching measures on the Loess Plateau

Soil microbial nutrients and resource availability improve with mulching in agroecosystems, resulting in changes of soil microbial nutrient utilization strategies. However, the responses of soil microorganisms to nutrient utilization processes to regulate community assembly and thus maintain resource availability have not been clarified. Here, we performed a long-term field experiment with mulching measures, including no-mulching (NM), straw mulching (SM), plastic mulching (PM), and ridge mulching (RM), conducted on the Loess Plateau of China, to explore the community assembly process in response to microbial nutrient utilization. Microbial nutrient utilization strategies were analysed by measuring soil nutrients, microbial biomass, and extracellular enzyme activities. The results showed that PM and RM acquired C and N nutrients by secreting C- and N-extracellular enzymes in response to C:N- and C:P imbalances in soil chemistry, thereby reducing the nutrient limitation on microbial metabolism and improving microbial C utilization efficiency (CUE). Soil extracellular enzymatic stoichiometry increased and N utilization efficiency (NUE) decreased under mulching and drove an increase in beta-diversity and dominant species abundance in fungal communities. Mulching measures promoted the modular distribution of sensitive microorganisms and aggregation of fungal networks under PM and RM by reducing the stoichiometric imbalance and extracellular enzymatic N:P. At the same time, the microbial community assembly gradually changed from a stochastic to a deterministic process in response to the alleviation of soil C:P imbalance and changes in microbial nutrient utilization, in which the fungal community was dominant. In conclusion, soil microorganisms adaptively responded to changes in soil microbial nutrient utilization through the enhancement of aggregation of fungal co-occurrence networks and deterministic assembly processes. This study provides a better understanding of the impact of mulching on microbial nutrient utilization strategies from a community assembly perspective.

Improving Morpho-Physiological Indicators, Yield, and Water Productivity of Wheat through an Optimal Combination of Mulching and Planting Patterns in Arid Farming Systems

Mulching practices (M), which conserve soil water and improve water productivity (WP), are receiving increasing attention worldwide However, so far, little attention has been given to investigating the effects of the integrations of mulching and planting patterns (IMPPs) on spring wheat performance under arid regions conditions. A two-year field study was conducted to compare the effects of eight IMPPs on growth parameters at 80 and 100 days after sowing (DAS), growth indicators, physiological attributes, grain yield (GY), and WP of wheat under adequate (1.00 ET) and limited (0.50 ET) irrigation conditions. The IMPPs included three planting patterns (PPs), that is, flat (F), raised-bed (RB), and ridge–furrow (RF), in combination with three M, that is, no-mulch (NM), plastic film mulch (PFM), and crop residues mulch (CRM). The results indicated that PPs mulched with PFM and CRM significantly increased growth indicators, different growth parameters, physiological attributes, GY, and WP by 6.9–39.3%, 8.2–29.2%, 5.2–24.9%, 9.9, and 11.2%, respectively, compared to non-mulched PPs. The F and RB patterns mulched with CRM were more effective in improving growth parameters at 100 DAS (2.7–13.6%), physiological attributes (0.2–20.0%), GY, and WP (9.7%) than were the F and RB patterns mulched with PFM under 1.00 ET, while the opposite was true under 0.50 ET conditions. Although the RFPFM failed to compete with other IMPPs under 1.00 ET, the values of different parameters in this PP were comparable to those in F and RB patterns mulched with PFM, and were 1.3–24.5% higher than those in F and RB patterns mulched with CRM under 0.50 ET conditions. Although the RFNM did not use mulch, the values of different parameters for this PP were significantly higher than those of F and RB patterns without mulch. Irrespective of irrigation treatments, the heatmap analysis based on different stress tolerance indices identified the different PPs mulched with PFM as the best IMPPs for the optimal performance of wheat under arid conditions, followed by PPs mulched with CRM. The different growth indicators exhibited second-order and strong relationships with GY (R2 = 0.78 to 0.85) and moderate relationships with WP (R2 = 0.59 to 0.79). Collectively, we concluded that using PPs mulched with CRM is the recommended practice for achieving good performance and production for wheat under adequate irrigation, whereas using PPS mulched with PFM is recommended as a viable management option for sustainable production of wheat and improving WP under limited irrigation in arid countries.

Evaluating the effects of plastic film mulching duration on soil nitrogen dynamic and comprehensive benefit for corn (Zea mays L.) field

Regulating the plastic film mulching duration was a good strategy to decrease plastic residues and to avoid the stress from low soil nitrate concentration (SNC). However, few studies focused on soil nitrogen dynamic under different mulching durations, especially for the impacts of soil nitrogen loss on crop yield and comprehensive benefits have not been revealed. In this study, HYDRUS (2D/3D) model was used to evaluate the differences of SNC and NO3-N leaching (NL) under no mulching (NM), mulching for the seedling stage (PMS), mulching for the elongation stage (PME), mulching for the tasseling stage (PMT), and mulching for the entire corn growth season (PMW). Additionally, a two-year (2019–2020) field experiment was carried out to measure SNC, NL, N2O, and NH3 emissions and to calibrate and validate the model accuracy. The effect of soil nitrogen loss on the comprehensive benefits under different mulching durations was further analyzed using a comprehensive multi-objective model. The results showed that HYDRUS (2D/3D) could well capture SNC dynamic under different mulching treatments, with average the normalized root mean square error of 16.5% in the validation period. There was no apparent difference in SNC, N2O emission, NH3 emission, and NL under different mulching durations in the seedling stage. However, the corresponding difference markedly increased with corn growth and development, especially in 2019. The average SNC (0–20 cm soil depth) under NM was higher by 9.2%, 25.0%, 21.2%, and 19.4% than PMS, PME, PMT, and PMW, respectively. Nitrogen emission (N2O and NH3) showed an increase trend with the shortening of mulching duration, i.e., NM>PMS>PME >PMT >PMW, while an opposite trend was found for NL. In general, PME was found to be the optimal mulching duration with the highest comprehensive evaluation score of 1782.7. Therefore, PME can be recommended to apply in this region to promote the developments of sustainable agriculture.

The Effects of Plastic Mulching Combined with Different Fertilizer Applications on Greenhouse Gas Emissions and Intensity, and Apple Yield in Northwestern China

Plastic mulching reduces weeds, conserves soil water, and boosts crop yield. However, most studies are insufficient when determining how plastic mulching affects greenhouse gas (GHG) emissions, particularly when used in conjunction with fertilizers. The purpose of this study was to determine the combined effect of plastic mulching and fertilizers on GHG emissions in apple orchards. A 3-year field experiment was conducted with two factors: mulching and fertilizers; (1) mulching treatments: plastic film (PM) and no mulching (NM); and (2) four fertilizer treatments: control (CK), organic fertilizer (M), inorganic fertilizer (NPK), and organic combined with inorganic fertilizer (MNPK), arranged in a two factorial randomized complete block design. The results showed that the mean annual N2O emissions ranged from 0.87 to 5.07 kg ha−1 in PM and from 0.75 to 2.90 kg ha−1 in NM. The mean CO2 emissions ranged from 2.10 to 6.68 t ha−1 in PM and from 1.98 to 4.27 t ha−1 in NM. MNPK contributed more to N2O and CO2 emissions in both PM and NM. The mean CH4 uptake rate ranged from 1.19 to 4.25 kg ha−1 in PM and from 1.14 to 6.75 kg ha−1 in NM. M treatment contributed more to CH4 uptake in both PM and NM. NKP treatments had higher greenhouse gas intensity (GHGI) in PM and NM, while MNPK and NPK treatments had higher greenhouse gas potential (GWP) in PM and NM, respectively. These results suggest that plastic film mulching significantly raises the potential for soil GHG emissions and increases apple yield.

Effects of plastic film mulching and nitrogen fertilization on the emissions of greenhouse gases from vegetable field in Southwest China

This study identified the influence of plastic film mulching (FM) and nitrogen (N) fertilization on the CH4 emission, the global warming potential (GWP) and the greenhouse gas intensity (GHGI) in a summer-hot pepper and winter-radish rotation field from May 2014 to April 2017. The experiment had 8 treatments including no-mulching (NM) and plastic film mulching with four different N fertilization rates (0, 150, 300 and 450 kg N ha−1 and 0, 100, 200 and 300 kg N ha−1 in the respective hot pepper and radish growing periods). The results indicated that FM as well as N fertilization had insignificant effects on CH4 emissions in the hot pepper and radish growing periods (P > 0.05). Relative to NM, FM had little effect on GWP (P > 0.05) but lowered GHGI substantially (P < 0.05) during the hot pepper growing period. During the radish growing period, FM enhanced GWP and GHGI significantly (P < 0.05). Additionally, N fertilization significantly enhanced GWP and vegetable yields both in hot pepper and radish growing periods (P < 0.05). In hot pepper growing period, N fertilization increased GWP more significantly than yield which resulted in increased GHGI with N fertilization rate, and the promotion effect of N fertilization on hot pepper yield was strongest at 150 kg N ha−1 with a relatively low GHGI. However, in radish growing period, N fertilization increased yield more significantly than GWP which resulted in the decreasing effect of N fertilization on GHGI, and the promotion effect of N fertilization on radish yield was strongest at 300 kg N ha−1 with a relatively low GHGI. Therefore, FM with 150 kg N ha−1 and NM with 300 kg N ha−1 were respectively recommended for the hot pepper growing period and radish growing period to achieve high vegetable yields and mitigate greenhouse gas (GHG) emissions simultaneously under the present vegetable field condition in Southwest China.

Reducing plastic film mulching and optimizing agronomic management can ensure food security and reduce carbon emissions in irrigated maize areas

Increasing crop yields to ensure food security while also reducing agriculture's environmental impacts to ensure green sustainable development are great challenges for global agriculture. Plastic film, widely used to improve crop yield, also creates plastic film residue pollution and greenhouse gas emissions that restricts the development of sustainable agriculture. So, one of those challenges is to reduce plastic film use while also ensuring food security, and thus promote green and sustainable development. A field experiment was conducted during 2017–2020 at 3 farmland areas, each with different altitudes and climate conditions, in northern Xinjiang, China. We investigated the effects on maize yield, economic returns, and greenhouse gas (GHG) emissions of plastic film mulching (PFM) versus no mulching (NM) methods in drip-irrigated maize production. We also chose maize hybrids with 3 different maturation times and used 2 planting densities to further investigate how those differences more specifically affect maize yield, economic returns, and greenhouse gas (GHG) emissions under each mulching method. We found that by using maize varieties with a utilization rate of accumulated temperature (URAT) <86.6 % with NM, and increasing the planting density by 3 plants m−2, yields and economic returns improved and GHG emissions reduced by 33.1 %, compared to those of PFM maize. The maize varieties with URATs between 88.2 % to 89.2 %, had the lowest GHG emissions. We discovered that by matching the required accumulated temperatures of various maize varieties to environmental accumulated temperatures, along with filmless and higher density planting, and modern irrigation and fertilization practices, yields increased and residual plastic film pollution and carbon emissions reduced. Therefore, these advances in agronomic management are important steps toward reducing pollution and achieving carbon peak and carbon neutrality goals.

Effects of Biodegradable Plastic Film on Carbon Footprint of Crop Production

Polyethylene film mulch (PM) is a kind of widely used technology to improve crop yields worldwide; however, because of a problem related with plastic residual pollution, it has gradually been replaced by biodegradable plastic film mulch (BDP). Although BDP has helped to solve the plastic residual pollution, its consequences in terms of greenhouse gas (GHG) emissions have rarely been revealed. Related knowledge is important for forming low-carbon development strategies for the plastic industry and agriculture. The objective of this study is to evaluate the influence of BDP on GHG emissions at different stages of its life cycle, and determine whether replacing polyethylene (PE) film with BDP film is a helpful way to reduce national GHG emissions. The results of this study suggest that the application of BDP improved the GHG emissions associated with agricultural inputs, but induced lower GHG emissions at the growing stage and the waste disposal stage, and resulted in lower total area-scale GHG emissions. Compared to the no mulch (NM) cultivation system, the yield-scale carbon footprint was reduced in both the PM and BDP cultivation systems, which meant that both PM and BDP produced lower GHG emissions than NM for the production of the same amount of grain. It was concluded that BDP is not only a measure to control the problem of plastic residue pollution in agriculture, but it can also mitigate the GHG emissions.

Distribution of microplastics in soil aggregates after film mulching

Microplastic distribution is non-homogeneous in agricultural soil following plastic film degradation. However, the distribution of microplastics by shape and particle size in different soil aggregates remains unknown. To elucidate the distribution of microplastic shapes and particle sizes in soil aggregates with increasing years of film mulching, four paired fields with film mulching (FM) and no mulching (NM) were examined at 1, 5, 10, and 20 years after continuous mulching. An increase in soil aggregates of 0.053–0.25 mm diameter was observed; however, soil organic carbon content decreased after long-term FM. Microplastics primarily combined with 0.053–2 mm soil aggregates. Specifically, long-term FM was associated with dominance of film- and fiber-shaped microplastics in soil aggregates of 0.25–2 mm and 0.053–0.25 mm diameter, respectively. Fiber- and granule-shaped microplastics of 0.25–1 mm diameter primarily combined with 0.053–0.25 and 0.25–2 mm soil aggregates, respectively. Film-shaped microplastics of diameter > 1 mm and diameter 0.05–0.25 mm primarily combined with 0.25–2 mm soil aggregates. Therefore, distribution of microplastics in soil aggregates can be used to monitor soil health and quality, greatly enhancing our understanding of the risk posed by microplastics to the environment.

Bacterial communities in proso millet root‐associated compartments are regulated by growth period and mulching regime

AbstractMulching regimes have a promoted impact on the soil hydrothermal environments and crop productions. However, the time‐dependent variations in root‐associated microbial communities under distinct mulching regimes in the Loess Plateau have not been thoroughly explored. Here, we investigated the regulatory impacts of plastic film mulching (FM) and ridge‐furrow mulching system (RF) on the microbial community compositions, diversities, and ecological networks in the distinct compartments (e.g., root, rhizosphere, and bulk soil) at jointing and flowering periods of proso millet, and we compared these two regimes to no mulching (NM). Mulching regimes improved the bulk and rhizosphere soil quality at jointing period, whereas reduced them at flowering period. Bacterial structure and composition of the three compartments were significantly influenced by growth periods and mulching regimes. Furthermore, mulching regimes effectively increased the alpha diversities of rhizosphere and root communities at flowering period. Soil temperature and total N were the most essential variables affecting the bulk soil and rhizosphere community structure, respectively. With the growth and development of proso millet, the network complexity and stability increased, and the abundance of different modules in the three compartments were regulated by mulching regimes. Proteobacteria and Acidobacteriota were the keystone species at jointing period, whereas, at flowering period, only Proteobacteria were the keystone species. In addition, FM regime significantly increased the species interaction and abundance of keystone taxa than those of non‐mulching at both periods. These results highlighted that mulching regimes were observed to be a recommended selection for improving soil quality, regulating bacterial diversity and structure, and stabilizing the species interaction, thereby providing guidance for choosing the ideal cultivation techniques from the perspective of microbial ecology in the Loess Plateau.

Strawberry Production with Different Mulches and Wetted Areas

The use of mulch contributes to the reduction of water consumption and weed infestation in strawberry cultivation. Recycled paper, being biodegradable, has great potential to replace plastics. Thus, the objective was to evaluate the water consumption and agronomic performance of strawberry subjected to different wetted areas and mulches. The wet areas tested were 40% (WA40) and 70% (WA70) imposed by a drip irrigation system. The different types of mulch were: white polyethylene (WHP), black polyethylene (BLP), recycled paper (REP) and no mulch (NM). BLP, REP and WHP mulches promoted the same weed control. The number of fruits per plant, fruit length, fruit yield, and water productivity did not differ for the factors wetted area and types of mulch. Higher fruit mass and diameter were found in the WA40 treatment, while the mulches favored only fruit mass. Thus, fruit yield showed no difference, and only water consumption differed between the wet areas and between the types of mulch. Strawberry water consumption was higher in WA70. In relation to fruit waste, it was found that the WHP and BLP mulches provided higher values than REP and NM. Thus, the recycled paper, combined with a wet area of 40%, is recommended as a mulch in strawberry production.

Effects of soil mulching on staple crop yield and greenhouse gas emissions in China: A meta-analysis

Food security and global warming in the 21st century are two major challenges for agricultural development. Soil mulching either with plastic film or straw is a common agricultural practice, which can improve crop growth by reducing evaporation and regulating soil temperature, and is widely applied globally. Although soil mulching can significantly affect crop yield and greenhouse gas (GHG) emissions, there is controversy regarding its effect on crop yield and GHG emissions in the long run. We conducted a meta-analysis to explore the impact of soil mulching practices on maize, wheat, and rice yield and GHG emissions in China. Our results demonstrated that soil mulching improved crop yield (16 – 22%), and its impact on GHG emissions varied with crop, region, and mulching method. Plastic film mulching (FM) and straw mulching (SM) increased yield by 28% and 9% compared with no-mulching (NM), respectively. FM decreased methane (CH4) emissions in paddy by 51%, and CH4 uptakes in upland by 23%, but SM increased CH4 emissions in paddy by 140%. Soil mulching increased carbon dioxide (CO2) emissions of maize and wheat by 13% and 12% than NM, respectively. CO2 emissions under FM decreased when ATP > 911.8 mm and AMT > 15.6 °C. N2O emissions under soil mulching may be reduced when nitrogen input is greater than 144 kg N ha−1. This showed that the reasonable use of soil mulching has the potential to achieve a win-win strategy to ensure food security and mitigate climate change.

Biodegradable Films Prepared from Pulp Lignocellulose Adhesives of Urea Formaldehyde Resin Modified by Biosulfonate.

Traditional low-density polyethylene (LDPE) film causes environmental pollution; there is a pressing need to make new bio-based polymers for alternative products, to meet agricultural production needs and for sustainable ecological development. In this study, urea-formaldehyde resin (UF) was modified with polyvinyl alcohol (PVA) and 1–2.5% bio-based sulfonate (BBS). The influence of BBS inducing on the functional groups, microstructure, and thermal behavior was evaluated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). A biodegradable film was prepared with modified UF resin as adhesive and pulp lignocellulose as raw material. The biodegradable mulch film samples were tested for biodegradability, water retention, and cooling soil temperature characters using LDPE and no mulching (NM) as a control. The results showed that with the increase of BBS content, the viscosity and reactivity of modified PUF resin increased, and the free formaldehyde content decreased. A 2%BBS modified PUF resin (2.0BBS/PUF) accelerated the curing process of the PUF resin, formed a flexible macromolecular network structure, and enhanced the toughness of the resin. The biodegradable mulch prepared with PUF, BBS, and 2.0BBS/PUF as adhesives had good water retention. BBS modification increased the degradation rate of mulch by 17.53% compared to the PUF. Three biodegradable films compared with LDPE and NM significantly reduced the soil temperature under summer cucumber cultivation, and the 2.0BBS/PUF coating had the lowest diurnal temperature difference, which provided a suitable soil environment for crop growth.

Evaluating soil salts dynamics under biodegradable film mulching with different disintegration rates in an arid region with shallow and saline groundwater: Experimental and modeling study

Soil salinization caused by shallow, saline groundwater represents a serious threat to field productivity, especially in arid regions with intense soil evaporation. Plastic film mulching (PM) has been increasingly applied to reduce soil evaporation and alleviate soil salinity stress. However, PM introduces into the soil a significant amount of plastic residues. Although biodegradable film mulching (BM) is an ideal alternative to PM due to the degradability of these films, unreasonably high disintegration rates may reduce the benefits of the proposed solution. Understanding the effects of these factors on soil salinity is essential for designing management options for improving water productivity. A two-year cornfield experiment was therefore carried out during 2019–2020 to evaluate differences in soil salt dynamics among treatments with BMs with low, medium, and high disintegration rates (BML, BMM, BMH), one polyethylene film mulching (PM), and no mulching (NM). Additionally, the HYDRUS-2D model was used to evaluate the electrical conductivity of the saturation paste extract (ECe), soil salt fluxes, salt distributions, and salt mass balances in two-dimensional soil profiles under BML, BMM, BMH, PM, and NM. The results showed that calibrated HYDRUS-2D could precisely simulate soil salinity under different mulching treatments. There were large differences between various treatments in the middle and late crop growth stages (Days After Sowing [DAS] 61–140). The highest ECe among different BM treatments occurred in BMH. Additionally, the two-dimensional distribution of soil salinity under BM was affected by irrigation events. The high soil salinity stress area (ECe > 3.80 dS m−1) occurred one day after irrigation (DAS 108) only under BMH among different BM treatments. Meanwhile, root water uptake (RWU) and crop yield (CY) under BMH were significantly reduced due to excessive accumulation of soil salinity in the root zone under intensive soil evaporation conditions. Compared with BMH and BMM, BML increased CY and the leaching ratio of soil salts from the root zone due to its good performance in water conservation. Thus, BM with a low disintegration rate is more efficient in controlling soil salinization in soils with a shallow groundwater table than BMs with higher disintegration rates due to lower soil evaporation. The findings of this study improve the understanding of the mechanisms of salt dynamics under biodegradable film mulching with different disintegration rates. The study also recommends to the farmers and government a suitable disintegration rate of the biodegradable film that can be adopted to promote field productivity.

Effects of plastic film mulch biodegradability on nitrogen in the plant-soil system

The application of biodegradable film mulching (BFM) instead of non-biodegradable film mulching (NBFM) is a promising way to mitigate the negative impacts of residual film in agricultural mulching systems. But the effects of BFM on soil mineral nitrogen (N) are not known. To investigate the effects of BFM on N mineralization, nitrate (NO3−) accumulation and leaching, and plant N uptake, we conducted two-year field experiment with five treatments: no-mulching (No-M), white non-biodegradable film mulching (White-NotBioM), black non-biodegradable film mulching (Black-NotBioM), white biodegradable film mulching (White-BioM), and black biodegradable film mulching (Black-BioM). The net N mineralization in NBFM was greater than that in BFM due to the disintegration of biodegradable films in the middle and late stages of maize growth, resulting in a decrease in soil water content under BFM. Higher net N mineralization caused a higher NO3− accumulation in the topsoil (0–20 cm) under NBFM. The NO3− accumulation in the topsoil in Black-NotBioM was 23–88% higher than that in Black-BioM; while in White-NotBioM it was 16–63% higher than that in White-BioM. After two years of cropping, the NO3− accumulation in 100–180 cm (defined as N leaching in deep layers, NLD) in NBFM was 52–63% higher than that in BFM, implying that the higher NO3− accumulation in the topsoil in NBFM caused more N leaching. The yields and plant N uptake were similar between NBFM and BFM, but BFM had higher N harvest index values. Compared with NBFM, BFM showed less NO3− accumulation in the topsoil and less NLD, whereas yield, plant N uptake and net economic benefits were not reduced. Therefore, BFM, especially Black-BioM, could be an alternative to NBFM in maize production on the Loess Plateau. However, the higher N accumulation in root soil layer (0–100 cm) under Black-BioM should be accounted for in N fertilizer management.