Straw Management Research Articles

Effects of Nutrient Deficiency on Crop Yield and Soil Nutrients Under Winter Wheat–Summer Maize Rotation System in the North China Plain

The wheat–maize rotation system in the North China Plain (NCP) has a large amount of crop straw. However, improper crop straw management and blind fertilization lead to nutrient imbalance and accelerated nutrient loss from the soil, ultimately leading to nutrient deficiency affecting the wheat–maize rotation system. In order to explore the effects of nutrient deficiency on the yield and nutrient use efficiency of wheat and maize, the experiment was conducted in a randomized complete block design consisting of five treatments with three replicates for each treatment: (1) a potassium fertilizer deficiency and appropriate nitrogen and phosphate fertilizer treatment (NP); (2) a phosphate fertilizer deficiency and appropriate nitrogen and potassium fertilizer treatment (NK); (3) a nitrogen fertilizer deficiency and appropriate phosphate and potassium fertilizer treatment (PK); (4) an adequate nitrogen, phosphorus, and potassium fertilizer treatment (NPK); and (5) a no-fertilizer treatment (CK). The results showed that, compared with CK, the yields of wheat and maize treated with NPK were increased by 21.5% and 27.5%, respectively, and the accumulation of the dry matter of the wheat and maize was increased by 42.5% and 57.3%. In all the deficiency treatments, the NK treatment performed better in terms of yield compared to the NP and PK treatments, while the NP treatment demonstrated a greater increase in dry matter accumulation. The NPK treatment significantly improved the nitrogen use efficiency (NUE) and nitrogen harvest index (NHI) of the wheat and maize, which resulted in higher nitrogen accumulation in the NPK treatment, and the NP treatment was the best among the other nutrient deficiency treatments. The inorganic nitrogen content showed a similar trend. In conclusion, nutrient deficiency can severely restrict crop growth. Nitrogen deficiency can significantly reduce crop yields. Phosphorus deficiency had a greater impact than potassium deficiency in terms of nutrient absorption and accumulation. Therefore, nitrogen fertilizer application should be emphasized in crop rotation systems, with moderate increases in phosphorus fertilizer application. This practice can effectively improve the nutrient deficiency under the wheat and maize rotation system in the NCP and complete a rational fertilization system.

Straw Mulching and Weather Conditions Affecting the Trade-Off Between Grain Yield and Agronomic Traits of Maize

Straw mulching (SM) plays an important role in promoting the grain yield (GY) of maize under no-tillage conditions. However, there is still a lack of deep understanding on the interactive impact of SM and weather conditions on agronomic traits and the contributions to GY. This study selected a cornfield in the North China Plain as the research object and set up a straw management experiment, including SM and no straw mulching (NSM). The GY and agronomic traits of maize from 2018 to 2020 were monitored, and the relationship of agronomic traits with GY and the weather conditions were analyzed. The results show that SM promoted maize GY by 20.44%. Straw mulching increased the plant height, ear diameter, and ear height by 8.43%, 1.99%, and 12.65%, respectively. A correlation analysis showed that the ear length and ear height were the main factors affecting maize yield. Ear length was significantly correlated with kernel numbers per ear in SM. Growing degree days, hot dry wind, and air temperature significantly affected kernel numbers per ear and plant growth. This study highlights the contributions of agronomic factors to maize GY under SM and variable weather conditions and is helpful to improve cropland management.

Performance Evaluation and Economic Sustainability of the PAU Model Batch Type Paddy Straw Biogas Plant

This study evaluates the performance and economic viability of the Punjab Agricultural University (PAU) Model Batch Type Paddy Straw Biogas Plant in rural India, addressing critical challenges in agricultural residue management and sustainable energy production. Data collected from two plants over four months showed an average daily biogas production of 1.46 to 3.13 m3 per day, with a total gas production of 284.8 m3 in a period of four months. Plant performance correlated moderately with ambient temperature. Economic analysis revealed annual savings of Rs. 47,600 through reduced LPG use and biogas slurry sales. The study concludes that the PAU Model is technically efficient and economically viable, offering a sustainable solution for paddy straw management and rural energy security. These findings have significant implications for policymakers and rural development practitioners in promoting sustainable agriculture and renewable energy adoption in developing regions.

The divergent role of straw return in soil O2 dynamics elucidates its confounding effect on soil N2O emission

The divergent effects of straw returns on nitrous oxide (N2O) emissions from soil require elucidation of the underlying mechanisms and factors that explain the inconsistency in in-situ conditions. We conducted a field experiment based on a long-term trial under different regimes of nitrogen (N) fertilization and straw management, complemented by laboratory incubation experiments involving visualized O2 dynamics imaging. In the field trial, we performed hourly basis high-time-resolution measurements of soil matrix oxygen (O2), N2O concentrations and fluxes during N2O “hot moment” events. We found that straw return increased cumulative N2O emissions by 32.7% under conventional high N input (Ncon), but showed no effect on N2O emission under optimized N input (Nopt). In situ O2 content and further microcosm experiments with visualized O2 spatiotemporal distribution suggested that long-term straw return increases porosity and soil O2 content, which reduced N2O emission under low N substrate conditions by improving soil pore structure and aeration during “hot moment” events. By contrast, straw return increased N2O emission via creating short-term O2 depletion zone and triggering denitrification in anoxic microsites when excess N substrate was available. Although straw return showed inconsistent effects on N2O emission under different N application rates, it consistently decreased N2O concentration in the soil matrix during the "hot moment" events, suggesting that straw return increases the transport of the produced N2O in soil matrix to the soil surface. Our study underscores the multifaceted role of straw return in soil O2 dynamics, i.e., stimulating O2 consumption in a short-term microscale of soil, but increasing soil porosity in a long-term mesoscale of soil. This explains the confounding effects of straw management on the production and transportation of soil N2O in situ and emphasizes the importance of optimized N fertilization for reducing the “hot moment” N2O emissions when straw is incorporated.

Effects of Fallow Season Water and Straw Management on Methane Emissions and Associated Microorganisms

The effects of fallow season water and straw management on methane (CH4) emissions during the fallow season and the subsequent rice-growing season are rarely reported, and the underlying microbial mechanisms remain unclear. A field experiment was conducted with four treatments: (1) fields flooded in both the fallow and rice seasons (FF), (2) fields drained in the fallow season and flooded in the rice season (DF), (3) FF with straw retention (FFS), and (4) DF with straw retention (DFS). The CH4 emissions in fields under different water and straw treatments were monitored using the static closed chamber method. Methanogenic and methanotrophic communities in these fields were examined using terminal restriction fragment length polymorphism (T-RFLP) analysis based on the mcrA gene and pmoA gene encoding methyl coenzyme M reductase and particulate methane monooxygenase, respectively. The results showed that CH4 emissions were significantly affected by water management, straw retention, season, and their interactions. Over 80% of CH4 emissions occurred during the rice season. Field drainage during the fallow season reduced CH4 emissions by 47.0% and 53.8% with and without straw during the rice season, respectively. Water management altered the abundance and composition of methanogens and methanotrophs, whereas the effects of straw retention were less pronounced. The quantitative polymerase chain reaction (qPCR) assay revealed that field drainage in the fallow season decreased the mcrA gene abundance by 30.0% and 23.2% with and without straw in rice season, respectively, and increased the pmoA gene abundance by 108.9% and 213.7% with and without straw in rice season, respectively. CH4 flux was significantly positively associated with mcrA gene copy number and the ratio of mcrA to pmoA gene copy number, whereas it was significantly negatively correlated with the pmoA gene copy number. Results indicated that fallow drainage greatly decreased CH4 emission not only during the fallow season but also during the subsequent rice season by altering the community composition of methanogens and methanotrophs. These findings provide scientific insight into the role of water and straw management in controlling CH4 emissions through microbial community dynamics.

Effect of Different Kharif Paddy Straw Management Options and Different Levels of Nitrogen on Soil Dehydrogenase and Urease Activity

A field experiment was conducted during rabi 2020-21, at Regional Agricultural Research Station, Polasa, Jagtial, PJTSAU to study soil dehydrogenase and urease activity as influenced by different kharif paddy straw management options and nitrogen levels. The results reveal that dehydrogenase and urease activity of soil was significantly influenced by paddy straw management options and activity was increased with crop duration up to 60 DAT and decreased after harvest. Dehydrogenase activity was reduced after burning (1.93 mg TPF produced g-1 soil d-1) as compared to the initial values (2.34 mg TPF produced g-1 soil d-1). The highest dehydrogenase activity of 3.74 and 3.54 mg TPF produced g-1 soil d-1 was recorded at 60 DAT in paddy straw incorporation with phosphorus and incorporation without phosphorus and decreased to 3.36 and 3.03 mg TPF produced g-1 soil d-1 after harvest respectively. Soil urease activity was showed an increasing trend with crop duration up to 60 DAT and then declined. Maximum activity of 3.05, 4.84, 5.17 mg NH4+ released g-1 soil h-1 was observed at 60 DAT under paddy straw burning, paddy straw incorporation with phosphorus incorporation without phosphorus respectively. Paddy straw incorporation with phosphorus recorded higher urease activity and paddy straw burning recorded lower urease activity at all the intervals of crop growth. The effect of nitrogen levels on soil urease activity was found to be significant. Soil urease was highest with 120% RDN followed by 115% RDN, followed by 110% RDN, followed by 100% RDN and the similar trend was observed at all the intervals of crop growth.

Strategies for crop straw management in China's major grain regions: Yield-driven conditions and factors influencing the effectiveness of straw return

Tailoring straw return strategies to specific regional conditions optimize soil health, crop yield, and carbon emission reduction. This study investigated yield-driven, spatial-scale, and long-term strategies for straw return of maize, rice, and wheat cultivation in China. Through a meta-analysis of 108 studies and the application of a machine learning model, the yield effects of straw return were thoroughly examined. Nitrogen fertilizer inputs were identified having the most significant impact on yield, and the yield benefits of straw return stabilized after approximately 13 years. A optimized strategy for straw return was developed for provinces in China, resulting in average yield increases of 13.9 % for maize, 12.2 % for wheat, and 14.0 % for rice. Implementing these locally adapted straw return strategies will contribute to the long-term development of sustainable agriculture in China.

Differentiated strategies for synergistic mitigation of ammonia and methane emissions from agricultural cropping systems in China

Ammonia (NH3) and methane (CH4) emissions from agricultural cropping systems in China have substantially impacted environmental quality and climate change, which become the key sector for synergizing pollution control and carbon reduction. However, the experiences of synergistic NH3 and CH4 emission governance at fine scales in this sector are still lacking. Here, we estimated NH3 and CH4 emissions from agricultural cropping systems in China in 2019 and identified regional characteristics of these emissions using advanced spatial analysis techniques. Subsequently, we developed an innovative synergistic mitigation zoning identification method to establish targeted and spatially differentiated reduction measures, addressing a critical gap in mitigation strategies for agricultural cropping systems in China. The results showed that NH3 and CH4 emissions from the three most important crops were 3.04 Tg N yr-1 and 8.13 Tg C yr-1, respectively. NH3 and CH4 emissions exhibited the highest values in Eastern China, but the highest emission densities of NH3 (49.8 kg N ha-1 yr-1) and CH4 (394 kg C ha-1 yr-1) were observed in Northwest and South China, respectively. Further, bivariate local indicators of spatial association (LISA) maps revealed that the middle and lower reaches of the Yangtze River were hotspots for simultaneous high emissions of NH3 and CH4. Finally, based on the identified eight categories of zones, region-specific mitigation measures were proposed, including improved fertilization practices, irrigation methods, and straw management. These targeted, spatially differentiated mitigation strategies provide a reference framework and feasible approach for synergistic pollution control and carbon reduction in China's agricultural sector.

Straw management and fertilization improve soil aggregate stability by inducing biological binding agents and specific keystone genera

Improving soil aggregate stability through proper fertilization management is essential for crop growth. However, how different fertilization regimes affect soil aggregate stability driven by microorganisms and biological binding agents remains largely unexplored. For this purpose, we conducted a 9-year field experiment involving two soil textures (i.e., loam and clay soils) and five fertilization regimes (i.e., no fertilizer or crop straw return (CK), crop straw return (S), chemical fertilization (N), crop straw return with chemical fertilizer (SN), and crop straw return with chemical fertilizer and 20% nitrogen substituted with chicken manure (SNM)). Mean weight diameter (MWD) of soil aggregates, glomalin-related soil protein (GRSP) content, and microbial community composition were investigated. The SN and SNM treatments had similar MWD, which was 70.08–76.45% higher than the CK, and the S and N treatments had similar MWD, which was 20.35–34.76% higher than the CK, indicating better effects of SN and SNM on the improvement of the soil aggregate stability than the S or N treatment. High easily extractable GRSP and total GRSP contents contributed to the improved MWD. Meanwhile, some specific keystone genera identified from the keystone modules (co-occurring groups of soil biota including arbuscular mycorrhizal fungi, bacteria, and nonmycorrhizal fungi) were recognized as the important factors regulating the MWD, though the selected specific genera in the loam soil differed from the clay soil. Altogether, our results highlighted the fundamental role of the GRSP and selected specific keystone microbial taxa in improving the soil aggregate stability and provided a list of microbial taxa linking to MWD in different soils, which could be specifically targeted in specific soil.

Studying Impact of Moisture, Node Position and Loading Rate of Paddy Straw on its Mechanical Properties

In this study, mechanical properties of paddy straw such as bending strength, shear strength and Young's modulus were determined through force-deformation curve using textural analyzer with 50 kg load cell. The mechanical properties were determined at three moisture contents, i.e., 18.4% (M1), 13.5% (M2) and 10.8% (M3), at three node positions, i.e., N1, N2 and N3 and three loading rates, i.e., 25, 30 and 35 mm min-1, respectively. The results revealed that moisture content and loading rate at different node positions significantly (p<0.01) affected the bending strength, shear strength, and Young's modulus of straw, whose values varied from 5.35 to 17.34 MPa, 4.99 to 7.35 MPa, 0.43 to 1.39 GPa, respectively, through N1 to N3 with decrease in moisture content; likewise, other findings also indicated increase in output values on increasing loads through N1 to N3. Cutting force was also significantly affected (p<0.01) by shear angle and moisture content, which varied from 6.39 to 22.9 N, and cutting energy ranged from 142 to 511 J by Straw Management System serrated blade and was found to be minimum at 20° shear angle. The mechanical property of the straw for residue management in the context of cutting force for node position N3 at the initial moisture content was found optimum.

Straw Returning With No‐Tillage Alleviates Microbial Metabolic Carbon Limitation and Improves Soil Multifunctionality in the Northeast Plain

ABSTRACTStraw returning has been broadly recognized as an agronomic strategy to manage soil quality and has great potential to enhance soil fertility. However, soil microbial metabolism and ecosystem multifunctionality in response to various straw returning strategies in the black soil remain poorly understood. Here, a 5‐year field trial was conducted to discover the effects of four straw management strategies (SIDP, straw incorporation by deep ploughing; SIRT, straw incorporation by rotary tillage; SM, straw mulching with no‐tillage; SR, straw removal with no‐tillage) on the soil biochemical properties in the topsoil (0–20 cm) and subsoil (20–40 cm). SM maintained soil fertility, as evidenced by increases in soil organic carbon, total nitrogen, dissolved organic carbon, and nitrogen, compared with SIDP and SR. Additionally, this strategy promoted microbial biomass. It also stimulated nutrient cycling through increased enzyme activity. Meanwhile, SM alleviated microbial carbon limitation and promoted the shift of soil microbial metabolism from P limitation to N limitation compared to other treatments, especially in the subsoil. This shift was directly influenced by soil available nutrients and microbial properties, as revealed by the partial least‐squares path modeling analysis. Besides, SM promoted soil ecosystem multifunctionality by 29%–37% in both soil layers compared to SIDP and SR. Random forest analysis indicated that soil microbial biomass and activity were the main drivers of this increase in multifunctionality. In conclusion, straw returning with no‐tillage is an optimal straw management strategy for improving the soil biochemical properties, stimulating enzyme activities, alleviating microbial carbon limitation, and increasing ecosystem multifunctionality in the Northeast Plain.

Assessing and enhancing sustainable rice straw management for environmental conservation in Yen Thanh District, Nghe An Province, Vietnam

This study assessed the current management of rice straw in Yen Thanh District, Nghe An Province, and propose solutions for sustainable agricultural development. A survey was conducted with 120 households in four communes to determine straw use and management practices. The findings revealed six common methods of using and managing rice straw in Yen Thanh District: open burning, burying, mushroom plantation, using it for husbandry feeding, selling, and giving it to others. These practices vary based on the crop season. Open burning is the most prevalent practice, accounting for 98.15% and 89.52% during the winter-spring and summer-autumn harvests, respectively. A crucial step in establishing a pollution control and management database is a comprehensive inventory of emissions. Consequently, authorities and environmental scientists are currently focusing on the emission inventory, particularly emissions resulting from open-burning rice straws. The estimated total amount of rice straw produced annually is 159,732 tons, with 151,384 tons being directly burned in the fields. This burning releases significant emissions, including 1,005.18 tons of PM2.5, 1,102.08 tons of PM10, 21.80 tons of SO2, 142,543.18 tons of CO2, and more, negatively impacting the environment, human health, and agriculture. Additionally, it was observed that most farmers are inclined to continue burning rice straw out of habit in the upcoming years. The study suggests promoting alternative straw management practices such as mushroom cultivation, biochar production, and organic fertilizer production to reduce burning and its associated negative consequences. This information would be invaluable for managers to effectively plan for the future management of rice straw

Greenhouse gas emissions during the rice season are reduced by a low soil C:N ratio using different upland-paddy rotation systems

ContextUpland-paddy rotation can improve multiple-cropping index and crop yields; however, the mechanisms underlying the effects of dry-season crop diversification on rice yields and greenhouse gas (GHG) emissions under multiple rotation systems remain unclear. ObjectiveHere, we aimed to clarify the intrinsic mechanisms whereby rice yields and GHG emissions respond to the diversification of dry-season crops and lay a theoretical foundation for developing agronomic measures that can stabilize yields and reduce GHG emissions. MethodsUsing a positioning experimental site for upland-paddy rotation, we measured rice-season CH4 and N2O emissions, crop yields, GHG-emission intensity (GHGI) levels, soil physical and chemical properties in garlic–rice (GR), wheat–rice (WR) systems for 3 years (2019–2020, and 2022), and in a rapeseed–rice (RR) system for 1 year (2022). The soil microbial dynamics of the three systems were only tested in 2022. ResultsThe WR system had the highest CO2 emission equivalent (CO2-eq), with a 3-year interval value of 1898.24–16794.30 kg·ha−1, the lowest yield (8490.10–9773.46 kg·ha−1), and the highest GHGI (0.22–1.83). The GR system had the highest rice yield (9718.91–10769.75 kg ha−1), a lower CO2-eq (1588.55–12567.51 kg·ha−1), and therefore a lower GHGI (0.16–1.24). The RR system had the lowest GHGI in 2022 (benefiting from the lowest CO2-eq) and a slightly higher yield than that of the WR system. CH4 contributed to >88 % of the CO2-eq under the three systems in 2020 and 2022. The higher soil C:N ratio of the WR system stimulated methanogenic microorganisms, coupled with higher microbial biomass C levels, and ultimately increased CH4 emissions substantially. The soil C:N ratios of the GR and RR systems were significantly lower than that of the WR system because the soil total nitrogen (TN) of both systems was higher and increased CH4 emissions were avoided. The higher levels of N nutrients (TN, NO3--N, and NH4+-N) in the GR and RR systems also enhanced rice yields, with respective increases of 10.37 % and 1.22 %, compared with that of the WR system. ConclusionsThe diversified cultivation of dry-season crops in upland-paddy rotation systems affected rice yields and GHG emissions by changing the ratios of C and N. ImplicationsOur findings highlight the importance of future research involving comprehensive agronomic measures to help reduce emissions, including fertilizer management, straw management, and tillage methods.

Constraints faced by farmers of Haryana in adoption of paddy straw management practices

Constraints faced by farmers of Haryana in adoption of paddy straw management practices

A P-graph Approach for Planning Sustainable Rice Straw Management Networks

The Philippines produces up to 15.2 Mt of rice straw waste annually. Unmanaged rice straw waste disposal can lead to pollution from open field burning. On the other hand, rice straw agricultural waste can be used sustainably to produce valuable products such as mushrooms, fodder, pellets, or bioenergy, in a rice straw management system. Such systems can be optimized using Process Integration tools so that the raw materials are used efficiently at the maximum profit and with a minimal carbon footprint. The P-graph framework is an efficient Process Integration tool that solves Process Network Synthesis problems. A P-graph finds the optimal and suboptimal solutions for further analysis, which is useful in decision-making. This work developed a P-graph model for a rice straw management network considering the straw collection and storage steps and the production of both bioenergy and non-bioenergy products. The model can generate optimal and sub-optimal solutions (based on profit) and can simulate raw material disruption scenarios. The model is demonstrated through a case study on three rice straw fields with a maximum total rice straw yield of 96.84 t/yr. The case study considered the operating and raw material costs but did not consider the fixed and investment costs in the calculation of the profit. The results show that mushroom production using rice straw as substrate is the optimal solution with a potential profit of US$ 14 659.60/yr, followed by pellet production with a potential profit of US$ 12 627.90/yr. Disruption scenarios at reduced diesel, manual labor, and rice straw show that mushroom production is still the optimum solution, showing the robustness of the solution. This basic model shows that P-graphs can be applied to rice straw management networks to aid with decision-making for sustainability. Caution must be exercised as the results are context- and location- specific.

Phosphorus application under continuous wheat-cotton straw retention enhanced cotton root productivity and seedcotton yield by improving the carbohydrate metabolism of root

ContextStraw retention could reduce phosphorus (P) application without decreasing seedcotton yield but related physiological mechanisms were unclear. Cotton root is the first organ to sense the changes in soil environment, and its growth and development, especially carbohydrate metabolism, significantly affected the formation of seedcotton yield. Therefore, it is necessary to explore the responses of cotton root carbohydrate metabolism to straw retention combined with P application. ObjectiveThis study was to investigate the effects of straw retention combined with P application on root carbohydrate metabolism and its relationship with seedcotton yield. MethodsA field experiment (2020–2022) was conducted to evaluate the changes in seedcotton yield, cotton canopy apparent photosynthesis rate (CAP), biomass, root productivity, root carbohydrate contents and related enzyme activities under different straw management [removal (S0), retention (S1)] and P rates (0, 100, 200 kg P2O5 ha−1). ResultsStraw retention and P application both increased seedcotton yield and had a significant interaction effect on it. In the 5th-7th year of straw retention, straw retention reduced 24 %-26 % P application to reach a similar yield of S0 with 100 kg P2O5 ha−1. Analyzing the reasons: (1) Straw retention combined with P application increased cotton CAP, providing adequate assimilates for cotton development; (2) Straw retention combined with P application promoted the utilization of root carbohydrates, thereby increasing root productivity and seedcotton yield. Specifically, compared with S0 without P, S1 combined with P application increased the enzyme activities related to carbohydrate metabolism, especially sucrose synthase (7.6 %-59.4 %) and acid invertase (3.9 %-58.6 %), which reduced sucrose (3.3 %-32.2 %) and starch (4.3 %-28.7 %) contents at the peak boll setting stage. Efficient utilization of sucrose and starch enhanced root productivity, the ratio of root to shoot (R/S) reduced by 2.7 %-21.6 %, while the boll loading of root system (BLR) and boll capacity of root system (BCR) increased by 0.6 %-39.2 % and 3.1 %-50.6 % at the boll opening stage, respectively, favoring the formation of seedcotton yield. Furthermore, when the R/S, BLR, and BCR reached 0.12, 0.81 boll g−1, and 4.33 g g−1, cotton harvested the maximum theoretical yield of 3780, 3774, and 4069 kg ha−1, respectively. ConclusionsStraw retention combined with P application increased root productivity and seedcotton yield by promoting the utilization of root carbohydrates. ImplicationsThis study revealed the internal mechanism for straw retention combined with P application to affect seedcotton yield from the angle of root carbohydrate metabolism and provided a theoretical basis for rationally reducing P fertilizer under straw retention.

Straw incorporation and nitrogen fertilization regulate soil quality, enzyme activities and maize crop productivity in dual maize cropping system

BackgroundStraw incorporation serves as an effective strategy to enhance soil fertility and soil microbial biomass carbon (SMBC), which in turn improves maize yield and agricultural sustainability. However, our understanding of nitrogen (N) fertilization and straw incorporation into soil microenvironment is still evolving. This study explored the impact of six N fertilization rates (N0, N100, N150, N200, N250, and N300) with and without straw incorporation on soil fertility, SMBC, enzyme activities, and maize yield.ResultsResults showed that both straw management and N fertilization significantly affected soil organic carbon (SOC), total N, SMBC, soil enzyme activities, and maize yield. Specifically, the N250 treatment combined with straw incorporation significantly increased SOC, total N, and SMBC compared to lower fertilization rates. Additionally, enzyme activities such as urease, cellulase, sucrose, catalase, and acid phosphatase reached their peak during the V6 growth stage in the N200 treatment under for both straw management conditions. Compared to N250 and N300 treatments of traditional planting, the N200 treatment with residue incorporation significantly increased yield by 8.30 and 4.22%, respectively. All measured parameters, except for cellulase activity, were significantly higher in spring than in the autumn across both study years, with notable increases observed in 2021.ConclusionsThese findings suggest that optimal levels of SOC, soil total N (STN), and SMBC, along with increased soil enzyme activities, is crucial for sustaining soil fertility and enhancing maize grain yield under straw incorporation and N200 treatments.

Design and assessment of tractor-driven chopping tilling and mixing machine for in-situ management of paddy straw

In many Indian regions, paddy wheat is the main crop rotation and facing the problem of straw incorporation for seed bed preparation in short period. The handling of straw in combine harvested paddy fields is a significant issue in the paddy wheat rotation. In order to solve this issue, efforts were carried out to cut paddy straw into small pieces by the newly proposed counter-rotating blades, followed by the simultaneous incorporation of a rotary tiller into the soil. Therefore, a tractor operated chopping cum tilling mixing machine was developed. In the study, three different blades (straw management system (SMS) Serrated, cutter bar and SMS plain) were tested in the terms of torque and required to chop the straw. SMS serrated blade was best suitable for the chopping mechanism as it required minimum cutting torque for the straw bunches. The developed chopping cum tilling mixing machine was tested at three different levels of forward speed (1.77, 2.3, and 3 km h−1), moisture content at three levels (35 ± 3.4, 24 ± 2.2 and 17 ± 2.6%) with fix rotary tiller rotational speed of 810 rev min−1. Optimum operating condition of the machine was obtained at a forward speed of 1.9 km h−1 and a moisture of 24%. At these optimized values, the mixing index (96%), mean weight diameter (7.9 mm), bulk density (1230 g cc−1) and fuel consumption (3 l h−1) were 96%, 7.9 mm, 1230 g cc−1 and 3.0 l h−1 respectively. The developed machine performs three operations i.e., chopping, tilling, and mixing in single pass for effective in-situ straw management.

Influence of microbial consortia mediated in-situ rice straw management options on yield, economics and energetics in rice-wheat cropping system

A field experiment was carried out during rainy and winter seasons of 2019–20 and 2020–21 at ICAR-IARI, New Delhi to study the effect of crop establishment methods and microbial consortia (Pusa decomposer) mediated in-situ rice straw management options on yield, economics and energetics of rice (Oryza sativa L) (cv. Pusa Basmati 1509) and wheat (Triticum aestivum L.) (cv. HD 2967). The experiment was laid out in split-plot design with three replications. The main plot consisted of two treatments viz., aerobic rice (AR) and conventional transplanted (CT) rice in wet season and seven sub-plot treatments viz. clean cultivation (removal of paddy straw), paddy straw incorporation (PSI), paddy straw mulching (PSM), PSI + Pusa decomposer (PD), PSM + PD, PSI + urea @ 20 kg/ha, PSI + PD + urea @ 10 kg/ha in dry season. In rice, results showed that grain yield (4.23 and 4.42 t/ha), net return (`69,470 and `71,682/ha) and energy output (157361 and 160950 MJ/ha) were significantly superior in CT rice than AR in main plots during both the years of experiment. However, sub-plot treatments showed a non-significant difference on these parameters. In wheat, among in-situ rice straw management options, paddy straw incorporation+ Pusa decomposer + urea @ 10 kg/ha treatment significantly resulted in higher grain yield (4.86 and 4.92 t/ha), net return (`62697 and `64801 /ha) and energy output (174951 and 176730 MJ/ha) compared to other treatments and control (clean cultivation). However, in main plots, statistically similar results were obtained with AR-wheat and CT-wheat. Thus, conventional rice transplanting resulted in significantly higher productivity and profitability over aerobic rice, however, AR consumed less energy (18.95%) and water (31.73%). Whereas, paddy straw incorporation+ Pusa decomposer + Urea @ 10 kg/ha was found effective in-situ rice management options with higher productivity and energy output compared to control.

Carbon savings from sugarcane straw-derived bioenergy: Insights from a life cycle perspective including soil carbon changes

Sugarcane straw removal for bioenergy production will increase substantially in the next years, but this may deplete soil organic carbon (SOC) and exacerbate greenhouse gas (GHG) emissions. These aspects are not consistently approached in bioenergy life cycle assessment (LCA). Using SOC modeling and LCA approach, this study addressed the life cycle GHG balance from sugarcane agroindustry in different scenarios of straw removal, considering the potential SOC changes associated with straw management in sugarcane-cultivated soils in Brazil. Long-term simulations showed SOC losses of up to −0.5 Mg ha−1 yr−1 upon complete straw removal, whereas the moderate removal had little effects on SOC and the maintenance of all straw in the field increased SOC accumulation by up to 0.4 Mg ha−1 yr−1. Our analysis suggests that accounting for SOC changes in LCA calculations could lower the net GHG benefits of straw-derived bioenergy, whose emissions intensity varied according to soil type. Overall, SOC depletion induced by complete straw removal increased the life cycle GHG emissions of straw-derived bioenergy by 26 % (3.9 g CO2eq MJ−1) compared to a scenario without taking SOC changes into account. Straw removal for cellulosic ethanol could be effective for mitigating GHG emissions relative to gasoline, but it was not advantageous for bioelectricity generation depending on the energy sources that are displaced. Therefore, straw-induced change of SOC stocks is a critical factor to model life cycle GHG emissions of straw-derived bioenergy.