Conventional Tillage Practices Research Articles

No tillage and leguminous cover crop improve soil quality in a typical rainfed Mediterranean system

Soil and crop management influence soil organic carbon (SOC), chemical composition, and overall soil quality. In a Mediterranean region, a study initiated in 1994 examined the long-term effects of conventional tillage (CT) versus no-tillage (NT) practices. Initially focusing on continuous durum wheat cultivation until 2009, the experiment later introduced a two-year rotation of durum wheat and Vicia faba L. cover crops in half of the CT and NT fields. SOC was monitored from 2008 to 2018, while microbial biomass (as dsDNA), soluble nitrogen (N), and enzyme activities (EAs) were monitored from 2011 to 2014 to evaluate the rotation's impact.
 Between 2009 and 2018, CT yields were on average 15% higher than NT, especially during high rainfall years. NT significantly increased SOC content in the 0-30 cm soil layer, along with higher levels of soluble N, dsDNA, and EAs at 0-10 cm depth. NT led to a 23% and 10% increase in SOC stock and SOC stock per equivalent soil mass respectively compared to CT. EAs increased by over 50% under NT, indicating enhanced biological activity. The SOC increase due to NT was limited to the top 10 cm, with a decrease at deeper depths (up to 50 cm). Introducing cover crops over four years did not yield significant impacts, suggesting the need for a longer period to observe noticeable effects.
 Overall, adopting NT practices resulted in higher SOC concentration, enhanced soil biological activity, and improved biogeochemical cycles, emphasizing the positive impact of no-tillage on soil health and sustainability.

Automated Crop Residue Estimation via Unsupervised Techniques Using High-Resolution UAS RGB Imagery

Crop Residue Cover (CRC) is crucial for enhancing soil quality and mitigating erosion in agricultural fields. Accurately estimating CRC in near real-time presents challenges due to the limitations of traditional and remote sensing methods. This study addresses the challenge of accurately estimating CRC using unsupervised algorithms on high-resolution Unmanned Aerial System (UAS) imagery. We employ two methods to perform CRC estimation: (1) K-means unsupervised algorithm and (2) Principal Component Analysis (PCA) along with the Otsu thresholding technique. The advantages of these methods lie in their independence from human intervention for any supervised training stage. Additionally, these methods are rapid and suitable for near real-time estimation of CRC as a decision-making support in agricultural management. Our analysis reveals that the K-means method, with an R2=0.79, achieves superior accuracy in CRC estimation over the PCA-Otsu method with an R2=0.46. The accuracy of CRC estimation for both corn and soybean crops is significantly higher in winter than in spring, attributable to the more weathered state of crop residue. Furthermore, CRC estimations in corn fields exhibit a stronger correlation, likely due to the larger size of corn residue which enhances detectability in images. Nevertheless, the variance in CRC estimation accuracy between corn and soybean fields is minimal. Furthermore, CRC estimation achieves the highest correlation in no-till fields, while the lowest correlation is observed in conventionally tilled fields, a difference likely due to the soil disturbance during plowing in conventional tillage practices.

Residual Effects of Microbial Treated Paddy Residues Applied to Zero Till Maize on Growth and Yield of Summer Greengram

Background: Farmers’ conventional tillage and residue removal practices in rice-maize-greengram systems in India are input-intensive, costly and soil degradative. A number of soil quality issues have emerged due to continuous cropping and burning of residues threatening the sustainability of rice based cropping systems for the last more than four decades. Nevertheless, the in-situ or in-field decomposition of crop residue using microbial inoculum is rarely studied. This necessitated the use of microbial consortia developed by a combination of potent strains of fungi which can perform harmoniously for rapid decomposition of crop residues. Methods: A field experiment was conducted during 2020-21 and 2021-22 with eight residue-management treatments and three fertility levels to zero till maize at college farm, Rajendranagar, PJTSAU using strip plot design and the residual effect on the succeeding greengram was studied. Result: Greengram growth and yield were significantly higher under residual effect of incorporation of residues treated with microbial consortia consisting of Trichoderma viridae, Aspergillus awamori and Phanerocheate spp. along with 300:100:100 kg ha-1 of N, P2O5 and K2O (125% RDF) and P supplied in the form of single super phosphate (SSP) under zero tillage during summer, 2021 and 2022. Growth parameters like plant height, leaf area index, dry matter production and yield attributes like number of pods plant-1, pod length and number of seeds pod-1 in greengram were higher under residue incorporated plots compared to residue burning, removal and retention plots with 125% RDF.

Nutrient Balance and Soil Fertility of Rainfed Maize-Wheat Cropping System Under Different Seed Priming, Tillage and Nutrient Management Practices

ABSTRACT Crop productivity, soil quality and fertility have been degraded due to intensive conventional tillage and poor crop management practices. Conservation tillage along with proper crop establishment methods (including seed priming, integrated nutrient management) helps in sustaining the productivity of crops, especially under rainfed conditions. A field experiment was carried out to evaluate the effect of seed priming, tillage and nutrient management practices on nutrient balance; chemical and microbial properties of soil; and productivity of maize-wheat cropping system in rainfed conditions. The experiment was laid out in factorial randomized block design with three factors (tillage, seed priming and nutrient management) and control as independent treatment for general comparison of results. The findings showed that chemical and microbial properties of soil were enhanced under zero tillage+ mulch as compared to other tillage practices. However, crop productivity was higher in conventional tillage+ mulch (70.28 q/ha (maize), 35.27 q/ha (wheat)). Under nutrient management practices, integrated nutrient management proved to be better as compared to recommended dose of fertilizers. Highest production efficiency (32.8 kg ha−1 day−1) was found under CT+M,Hydro,Int. Nutrient balance (N, P, K) was found higher in treatments with integrated nutrient management.

Combine Application of Zinc and Boron Improves Pearl Millet (Pennisetum glaucum) Performance Under No Tillage and Plough Tillage

No-tillage (NT) and crop rotation with green manure crops is a best alternative to plough tillage because it sustains environmental health, conserves natural resources and also improves crop growth and yield Conventional tillage practices result in losses of soil, water, and nutrients in the field, as well as degraded soils with low organic matter content and unstable physical structures, resulting in low crop yields and inefficient water and fertilizer usage. Micronutrient deficiencies, such as zinc (Zn) deficiency, is becoming more common in various annual crops as a result of continuous tillage. Zn has specific and essential physiological functions in plant metabolism, influencing yield and quality. Boron (B) plays an important role in the physiological process of plants, such as cell elongation, cell maturation, meristematic tissue development, and protein synthesis. To evaluate the role of Zn and B this experiment was performed in College of Agriculture BZU Bahaddar Sub Campus Layyah. Experiment was comprised of two tillage systems (No tillage and plough tillage) and three treatments application including (Zn, B, Zn+B) compared with control. These treatments were arranged according to RCBD split plot arrangement with net plot size of 1.8×4m. Findings of this study revealed that combine application of Zn and B boosted pearl millet growth and yield under no-tillage. Maximum relative water contents (RWC), membrane stability index (MSI), chlorophyll pigment, plant height, tillers per plant, leaf area index (LAI), stem diameter, length of ear head, seeds per ear, grain mass, grain yield, biological yield and 1000 grains were recorded when combine application of Zn and B was done under no-tillage. From the results it was concluded that pearl millet growth and yield can be maximized through combine application of Zn and B under no tillage.

Evaluation of different tillage and intercropping systems in castor under rainfed conditions

The field experiments were conducted in 2020-21 and 2021-22 at Tapioca and Castor Research Station, Tamil Nadu Agricultural University, Yethapur. The pooled result of the two-year study of different tillage practices in castor based legume intercropping systems in rainfed, there was no significant difference among tillage practices relevant to growth, yield attributing characters, seed yield and biomass yield, numerically higher values were registered under conventional tillage practices over minimum tillage. The higher seed yield of both base (1152 kg/ha) and inter crop (481 kg/ha) were recorded in conventional tillage practices over minimum tillage. With respect to inter cropping, higher base crop (castor) yield of 1058 kg/ha was recorded under castor + groundnut inter cropping system which was observed to be on par with sole castor (1020 kg/ha) and castor + greengram (907 kg/ha). The highest. Moreover, the maximum benefit-cost ratio was recorded in castor + groundnut (1:3) intercropping, over solecastor cropping.

Effect of conservation tillage on soil and water conservation, yield and yield components of Maize (Zea mays L.) in South Ari District, Southern Ethiopia

Reduced tillage is one of the options to combat land degradation problems. The study aims to examine the impacts of tillage practices on selected soil physicochemical properties, soil loss, and maize yield and yield components. Four treatments—zero, twice, and strip tillage—as well as farmers' practices, were set up in a randomized complete block design with five replications. Then, soil moisture, soil loss, and yield and yield components of maize data were collected. The findings show that, when compared to conventional tillage, conservation tillage improves soil moisture and decreases soil loss during and after crop development. The study found that implementing reduced, or zero tillage practices resulted in higher maize yields and long-term economic benefits for farmers compared to conventional and strip tillage practices. In addition, the current research demonstrated that, in comparison to strip tillage and conventional tillage, adopting reduced tillage and zero tillage increased maize yield and yield components with greater long-term economic benefits to farmers. The current findings also showed that adopting reduced tillage and zero tillage boosted maize yield and yield components, with higher economic benefits to farmers in the long run as compared to strip tillage and conventional tillage. Although zero tillage attributed to less grain yield, it resulted in higher economic benefits to farmers and saved 44.84% of soil loss relative to conventional tillage. The outcome of the economic evaluation unequivocally demonstrated that reduced tillage is the best approach, but zero tillage, strip tillage, and reduced tillage are all superior and advised for farmers. Hence, farmers can use either zero tillage or reduced tillage, depending on their investment capital. But to get considerable changes in soil and water balances, other soil physicochemical properties, and crop yield. Similar studies must be carried out on permanent field plots for longer than 2 years in the future.

Techniques for Conservation Tillage under 15–25% Slope: Soil and Water Conservation, Maize Yield and Yield Components in Basketo Zone, Southern Ethiopia

In steeply sloping regions of Ethiopia, water erosion is the primary cause of soil erosion and land degradation. Poor management of watersheds, inappropriate farming practices, and heavy rainfall all contribute to a continuous process of soil nutrient depletion in mountainous places. A quick loss of soil organic matter, soil deterioration, and a decline in environmental quality could result from the main farmer practice restrictions during plowing. To maintain agricultural productivity and environmental quality, a better farming system is therefore a significant method. This study was conducted in 3 farmer’s fields to investigate the significance of different cultivation practices on soil loss and maize yield under a slope of 19 % during cropping season in 2016 and 2018 at Motkesa Kebele of Basketo Zone, southern Ethiopia. The trial was laid out using a randomized complete block design through four treatments replicated three times on run-off plots. Experimental treatments used in the area were (strip tillage, zero tillage, reduced tillage and farmer practice) with maize planting at a spacing of 25cm by 75cm between plants and between rows respectively. According to the research result zero tillage decreased mean soil loss by 70% -74 % compared with conventional tillage (P < 0.05) and zero tillage has a great potential of controlling soil erosion on steep lands. Additionally, zero tillage was effective in conserving soil moisture increased (36-42%) compared with conventional tillage practices. According to the results of our research data, we advise that in smallholder household farms, the implementation of conservation agriculture has a cost-effective production management method, saves raw materials, increases yield, and reduces manual labor. Further studies are also encouraged in the same agroecology to promote the conservation agriculture system.
 Keywords: Conservation tillage; maize yield and yield components; soil moisture, soil loss

Subsoiling before winter wheat alleviates the kernel position effect of densely grown summer maize by delaying post-silking root-shoot senescence

Intensified kernel position effect is a common phenomenon in maize production under higher plant density, which limits the crop productivity. Subsoiling is considered as an effective agronomic practice to improve crop productivity. In order to clarify the effect of subsoiling before winter wheat on kernel position effect of densely grown summer maize and its regulatory mechanism, field experiments were conducted during 2020-2021 and 2021-2022 growing seasons by using a split-plot design. Main plot include two tillage practices: conventional tillage practice (CT) and subsoiling before winter wheat (SS); subplot consist three plant densities (D1-D3, 6.0×104, 7.5×104, and D3, 9.0×104 plants ha-1). Compared with CT, SS alleviated the kernel position effect by increasing the weight ratio of inferior to superior kernel (WR) of D2 and D3 treated plants. The higher WR of SS treated plants attribute largely to the improved filling of inferior kernel. Under the same plant density, SS significantly improved the root dry matter accumulation (DMA) and antioxidant enzyme activities (SOD and POD), and reduced malondialdehyde (MDA) concentration, especially for the plants grown under higher plant densities. These result indicated that SS delayed the root senescence, which is associated with the reduced soil bulk density. In addition, by comparison with CT, SS increased the leaf chlorophyll content from 20 days after silking to physiological maturity and post-silking leaf area duration, and decreased post-silking leaf chlorophyll reduction rate and leaf area reduction rate, reflecting the post-silking leaf senescence is alleviated. Under the same plant density, the post-silking DMA of SS was obviously higher than that of CT, which is probably related to the improved leaf area duration and photosynthetic enzyme activity (PEPC and Rubisco). The correlation analysis revealed that the main mechanism of SS in alleviating kernel position effect of densely grown summer maize is: SS delayed the post-silking root-shoot senescence by regulating soil physical properties, and further improved the post-silking DMA and filling of inferior kernel, ultimately alleviated the kernel position effect and improved grain yield. The present result will provide a new theoretical support for the promotion of summer maize yield by subsoiling before winter wheat.

Short Crop Rotation under No-Till Improves Crop Productivity and Soil Quality in Salt Affected Areas

Soil productivity and crop yield were examined in response to legume-based short crop rotation under conventional (CT) and no-till (NT) tillage practices in saline meadow-alluvial soils of the arid region in Bukhara, Uzbekistan. Compared with the CT treatment, crop yield was consistently higher under NT, i.e., winter wheat 9.63%, millet 9.9%, chickpea 3.8%, and maize 10.7% at the first experiment cycle during 2019–2021. A further crop productivity increase was observed at the second experiment cycle during 2021–2023 under NT when compared to CT, i.e., winter wheat 17.7%, millet 31.2%, chickpea 19.6%, and maize 19.1%. An increase in total phyto residue by 20.9% and root residue by 25% under NT compared to CT contributed to the improvement in soil structure and played a vital role in the sustained improvement of crop yields. In turn, the increased residue retention under NT facilitated soil porosity, structural stability, and water retention, thereby improving soil quality and organic matter content. Soil salinity more significantly decreased under NT than in CT, reducing salinity buildup by 18.9% at the 0–25 cm and 32.9% at the 75–100 cm soil profiles compared to CT. The total forms N and P were significantly increased under NT when compared to CT, while the efficiency of the applied crop rotation was essential. This study showed the essential role of the NT method with legume-based intensive cropping in the maintenance of soil health and crop yield, thereby touching on recent advances in agro-biotechnology and the sustainable land management of drylands.

An economic review of conservation tillage practices: select case studies from the eastern Prairies of Canada

This study reviewed the literature on soil conservation practices and analyzed four case studies in different soil zones and diverse cropping systems of Manitoba (MB), western Canada, to show the potential impacts of no-till/reduced tillage practices on field crop economic performance. Primary and secondary data, such as tillage type, input cost, crop price, crop yield, and net revenue (NR), were used to assess the tillage practices in each of the case studies. Based on crop economic analysis, over 9 years (1998–2006) in southern Manitoba, cereal-based (spring wheat ( Triticum aestivum L.) and barley ( Hordeum vulgare L .)) cropping systems were more profitable under conservation tillage than conventional tillage practices, whereas the opposite was true for oilseed crops (e.g., canola, Brassica napus L.). In plot-scale studies at Portage, MB, low intensity tillage increased NR for soybean ( Glycine max L.) in 1 of 3 years when compared to high intensity tillage, and there appeared to be lower NRs for canola as tillage intensity increased. However, in studies near Brandon, MB, NRs for a 4-year wheat-pea ( Pisum sativum L .) rotation were lower in low disturbance seeding than high disturbance seeding systems for a clay loam soil but similar for a loam soil. While no single tillage system was found to consistently provide the highest NR based on these case studies, these findings provide insights into some of the factors behind decisions surrounding tillage management and the rationale for the continued use of a combination of conventional, reduced, and zero-till systems in the eastern Prairies of Canada.

Long-term economic impacts of no-till adoption

No-till has long been considered a sustainable agricultural practice because of its potential to provide on-farm productivity benefits as well as off-site environmental benefits. However, “economic concerns” have been identified as one of the largest barriers to adopting no-till (i.e., costs associated with adoption possibly being greater than the returns in the short term). This study evaluates the long-term economic impact of no-till adoption using rich plot-level data from a long-term field experiment over the period 1996–2019. Linear fixed-effect models and partial budgeting techniques are used in the empirical analysis. Estimation results reveal that there are generally no statistically significant differences between long-term yields from no-till relative to the conventional tillage practice when considering corn, soybean, and wheat. Nonetheless, the partial budgeting analysis using the long-term data suggests that net returns (or profits) per acre tend to be greater for no-till compared to conventional tillage for all three crops. This is primarily due to the statistically lower farm operation costs associated with no-till. Moreover, our analysis also suggests that relative profitability of no-till increases as the practice is used longer over time. This insight supports suggestions from previous studies that long-term adoption of continuous no-till is important to best realize the benefits from the practice.

Effect of Tillage Management and Soil Slope on Annual Soil Loss under Cereal Crops in Central India

The negative impacts of soil erosion on productivity are mainly attributed to the decline in soil fertility and water availability. Continuous tillage practices combined with removal of crop residue from the soil surface greatly increase the risk of soil erosion and nutrient depletion. Soil erosion creates many adverse impacts on the environment and soil health which influence the food security and the quality of life. In present study the effect of three tillage management (conventional tillage, ridge and furrow system and no tillage system) and soil slopes (1%, >1% to < 3%, >3 to <5% and >5%) on soil loss in twelve different soil series under cereal cropping in central India has been studied. The results of the study indicated that the tillage management plays an important role to reduce soil loss. No tillage system found showed minimum annual soil loss whereas the conventional tillage practice recorded the most. The soil loss found decreased with decrease in slope and vice-versa. The Bararia soil series found most vulnerable to the soil loss whereas the Dhodar soil series found resistant to soil loss across the slopes and tillage management practices studied under cereal cropping in central India.

A Meta-Analysis Approach to Estimate the Effect of Cover Crops on the Grain Yield of Succeeding Cereal Crops within European Cropping Systems

Farming practices such as cover cropping, crop rotation systems, and soil tillage practices, along with climate conditions and soil type play important roles in determining final crop production. Numerous empirical studies have documented the heterogeneous effects of cover crops on the yield of successive crops, exhibiting variations across diverse regions, climate regimes, soil characteristics, cover crop types, and agricultural management practices. A meta-analysis was conducted to comprehensively summarize and evaluate the impact of cover crops (CCs) in the agroecosystem. The main goal of the study is to promote a transition towards more sustainable cereal crop production by exploring the potential of currently unexploited CCs in Europe. The study demonstrated that the incorporation of legume CCs resulted in the most pronounced and statistically significant increase in grain yield among cereal crops. CCs from the Brassicaceae family also demonstrated a positive impact on grain yield under southern European climates. Cover cropping had a positive effect on the subsequent cash crop under conventional tillage practice. A positive, but not significant impact, was detected under both conservation tillage practices, which include reduced tillage (RT) and no-till (NT). The result of the study suggests that NT practices are more suitable for Northern Europe, while RT practices are preferable for Southern Europe zones. This study indicates that the adoption of cover cropping represents a viable and effective agronomic strategy for enhancing grain yield in cereal crops cultivated across European agricultural systems.

Deriving Surface Water Storage and Curve Numbers from Rainfall–Runoff Relationships in Conventional and Minimum Tillage Systems in Gwanda, Zimbabwe

Soil water availability is one of the major constraints limiting crop productivity under semi-arid conditions in sub-Saharan Africa. Crop models are tools that can be used to explain and predict the effect of improved technologies on runoff and soil water availability, and their impact on crop productivity. The study hypothesized that minimum tillage treatments (planting basins and ripper) retain more rainwater and reduce runoff generation compared to conventional tillage treatments in maize-based cropping systems. Runoff plots were established on-farm and surface runoff was collected after each daily rainfall event. Surface water storage and curve number for each conventional and minimum tillage treatment were derived from the runoff and rainfall amounts measured over two growing seasons. Daily rainfall events of 9–76 mm generated runoff in both conventional and minimum tillage treatments. Planting basins retained more rainwater (12–19%) and reduced runoff generation (40–51%) than the conventional and ripper tillage treatments. Runoff generation in the tillage treatments varied with soil texture. Conventional and double ploughing treatments recorded more runoff (11–12%) in loamy sands than in sandy soil. Surface water storage and curve numbers from tillage treatments were consistent with runoff results and with conventional treatments, having higher curve numbers than minimum tillage practices. Conventional and ripper tillage practices have similar runoff potential as demonstrated by their curve numbers generated in this study. Curve numbers of 75–76 for conventional and 72–74 for minimum tillage systems are practical under light-textured soil and a land slope of <2% when conventional and minimum tillage practices are implemented.

In-Field Rainwater Harvesting Tillage in Semi-Arid Ecosystems: I Maize-Bean Intercrop Performance and Productivity.

The purpose of this study was to monitor and compare the growth and productivity of maize/beans sole and inter-cropping systems under conventional (CON) and in-field rainwater harvesting (IRWH) tillage practices. During the typical drought conditions of the 2018/19 growing season, seven homestead gardens of smallholder farmers (four in Paradys and three in Morago villages) in the Thaba Nchu rural communities of South Africa were selected for on-farm demonstration trials. Two tillage systems CON and IRWH as the main plot and three cropping systems as sub-treatment (sole maize and beans and intercropping) were used to measure crop growth and productivity parameters. The results showed that IRWH tillage had significantly higher above-ground dry matter for both sole maize (29%) and intercropped maize (27%) compared to CON treatments. The grain yield under both tillage systems showed that IRWH-Sole >> IRWH-Ic >> CON-Sole >> CON-Ic, with values ranging from 878.2 kg ha-1 to 618 kg ha-1 (p ≤ 0.05). The low harvest index values (0.21-0.38) could have been due to the effect of the drought during the growing season. The results of precipitation use efficiency (PUE) showed that the IRWH tillage was more effective at converting rainwater into maize biomass and grain yield compared to CON tillage. However, the different cropping systems did not show a consistent trend in PUE. During the growing season, the PUE for AGDM varied for different tillage and cropping system treatments in Morago and Paradys. For maize, it ranged between 10.01-6.07 and 9.93-7.67 kg ha-1, while for beans, it ranged between 7.36-3.95 and 7.07-3.89 kg ha-1 mm-1. The PUE for grain yield showed similar trends with the significantly highest values of PUE under IRWH tillage systems for the Morago sites, but there were no significant differences at the Paradys site in both tillage and cropping systems. There is a critical need, therefore, to devise alternative techniques to promote an increase in smallholders' productivity based on an improved ability to capture and use resources more efficiently.

Optimization of goat manure against use of N-Minjingu Nafaka Plus fertilizer for improved lablab growth and yield in semi - arid areas of Northern Tanzania

The study was conducted in Northern Tanzania from the 2022–2023 cropping seasons to develop a cropping model that farmers can use to improve their lablab production. The field experiments were conducted at the Tanzania Agricultural Research Institute, Selian station and was laid down in a Split Plot Designs with main factor being tillage system and sub-factor being fertilizer type (Goat manure and Minjingu Nafaka Plus). The trials consisted of three treatments (goat manure, Minjingu Nafaka Plus and the control-no fertilizer) replicated thrice. There were significant differences (p=<0.001) among the number of pods per plant, plant height and lablab grain yield. The highest grain yield (3952 g and 3933 g) with net benefit of (1,290,210Tshs and 1,249,175Tshs) was recorded in a plot treated with (Minjingu Nafaka Plus) fertilizer in Conventional and Zero tillage system compared with (Goat manure) which had (3944 g and 3928 g) with net benefit of (1,306,710Tshs and 1,292,675Tshs) in Conventional and Zero tillage practices. Conclusively, the study revealed that there were high net benefits under zero tillage compared to conventional tillage based on input-output costs analysis at both TARI - Selian and Saweni sites. Zero tillage was more economically viable than conventional tillage practices as becomes more friendly for the resource-constrained farmers in increasing their potential yield.

Long‐term conservation and conventional tillage systems impact physical and biochemical soil health indicators in a corn–soybean rotation

AbstractAgricultural management practices tend to influence soil structure stabilization, mediating many physical, chemical, and biological processes in soils. Therefore, understanding the long‐term effects of management practices on various soil health indicators is crucial to develop sustainable agricultural practices. This study aimed to assess the long‐term conventional and conservation tillage effects on soil physical (aggregates) and biochemical (soil organic carbon [SOC], enzymes, and microbial biomass) parameters under a range of tillage practices in a corn–soybean rotation in Nebraska. The experiment was conducted at two locations as follows: (1) Concord site (36 years) with the three treatments: no‐till (NT), disk, and moldboard plow; and (2) Lincoln site (40 years) with four tillage treatments: NT, double disk, chisel, and moldboard plow. Results showed that NT at both sites significantly increased SOC concentration by 24%–66% compared to moldboard plow. Similarly, double disk tillage increased SOC by 54% compared to the moldboard plow at the Lincoln site. Arylsulfatase, β‐glucosidase, hot‐ and cold‐water extractable carbon, microbial biomass carbon, and nitrogen concentrations significantly decreased with the increased tillage intensity at both sites. This implies that the NT increased these parameters compared to the disk and moldboard plow. However, aggregate size fraction 0.053–0.25 mm was the only parameter higher under moldboard plow (20.8%) than NT. Overall, the results from these long‐term studies indicate that NT, and to a lesser extent the reduced tillage practice of disk till, can improve soil health more than conventional tillage practices under a corn–soybean cropping system, suggesting the adoption of sustainable agricultural practices to improve soil health.

Ammonia-oxidizing bacteria are the primary N2O producers in long-time tillage and fertilization of dryland calcareous soil

Human intervention in agriculture, such as tillage and fertilization, could result in major changes of N2O emissions that understanding the N2O emission mechanism is of great significance in reducing the N2O emissions of the agricultural system. In this work, we focused on the conventional tillage practice and straw return practice used in the spring maize production system of this region and compared them by the addition of 3,4-dimethylpyrazole phosphate (DMPP) to explore the N2O emission mechanism of the farmland. Compared with conventional farming, straw return significantly increased the N2O emissions from the soil. Soil pH had important effects on soil N2O emissions through its influence on the ammonia oxidizer community. In addition, DMPP was used to distinguish N2O emissions driven by ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB), and the results showed that AOB were the dominant factor regulating N2O emissions after receiving nitrogen from an external source in dryland farming calcareous soil. Through the analyses of soil AOB community composition and the aggregated boosted tree (ABT) model for N2O emissions, Nitrosospira Cluster 3a.2 was found to be the main driving force of soil N2O emissions in AOB communities. These findings will help better understand the physiochemical and biological mechanisms underlying the N2O emissions of agricultural soils and provide insight for reducing the negative impact of agricultural production systems on the ecological environment.

The impact of conservation tillage intensities on mean yields and yield risk

Understanding the productivity and production risk effects of conservation tillage practices are important so that growers can make better decisions about tillage systems appropriate for their farm operations. This study investigates the mean yield and yield risk effects of conservation tillage practices with varying levels of tillage intensity and timing. Long-term field trial data for corn (Zea mays, L.) and soybeans (Glycine max, L. Merr.) in the North Carolina Piedmont, together with moment-based regression models, were used to achieve the objective of the study. Our empirical analysis suggests that conservation tillage treatments (with lower tillage intensities and higher residue levels) consistently have higher mean yields than conventional tillage practices in the sandy loam soils of the North Carolina Piedmont. However, we find that conservation tillage practices with lower intensities (and higher residue levels) do not generally have a consistent statistically significant risk reducing effect based on the higher-order moments of the yield distribution (e.g., variance, skewness, and kurtosis). This indicates that conservation tillage does not consistently result in statistically lower production risk relative to conventional tillage methods.