Reduced Tillage Research Articles

Changes in Biological and Chemical Soil Properties in an Austrian Long‐Term Tillage Experiment

ABSTRACTConventional tillage, including ploughing after harvest and/or for seedbed preparation, aims to incorporate crop residues and weeds and to loosen, mix and aerate the soil. However, less beneficial effects, such as a loss of soil organic carbon (SOC), are also associated with intensive tillage. This has made reduced and minimum tillage systems without ploughing increasingly popular in agriculture, contributing to soil health and climate change mitigation. We studied the effects of different tillage systems on chemical and microbial soil properties in a long‐term field experiment established on a fine‐sandy loamy Haplic Chernozem in Fuchsenbigl, Austria, in 1988. The tillage treatments include conventional tillage (CT) with a plough and a cultivator down to 30 cm soil depth, reduced tillage (RT) with a cultivator down to 15 cm two to three times a year, as well as minimum tillage (MT) treated with a rotary driller once a year down to 5–8 cm soil depth. In 2016, a soil sampling campaign was conducted, and alkaline phosphatase, phospholipid fatty acids (PLFAs), and the nitrogen (N) mineralisation potential were analysed along with chemical properties including SOC, active C, total nitrogen (Nt), CAL extractable phosphorus (PCAL) and potassium (KCAL). Under MT, these properties were significantly higher compared to CT in 0–10 cm. In deeper soil layers, these parameters showed very few significant differences between the tillage treatments. RT yielded intermediate values but not always significantly different from CT. PLFA indicators significantly correlated with SOC and, even more distinctly, with Nt and active carbon. The high ratio of Gram‐positive to Gram‐negative bacteria indicates more recalcitrant organic matter in the top layer in MT than CT.

Hairy vetch influence on nitrous oxide and nitrate leaching losses during corn growing seasons in reduced and no-till systems

Shifting from reduced tillage (RT) to no-till (NT) often reduces phosphorus (P) runoff by minimizing soil erosion. However, it might increase nitrous oxide (N2O) emissions or nitrate-N (NO3-N) leaching. Including a legume cover crop such as hairy vetch (Vicia villosa L.) before corn (Zea mays L.) is a common practice among growers in the Midwest USA. However, the effects of hairy vetch following soybean (Glycine max L.) harvest on NO3-N leaching and N2O emissions during the following corn season in soil with clay and fragipans are less assessed. This study evaluated the influence of cover crop (hairy vetch vs. no-CC control) and tillage systems (NT vs. RT) when 179 kg ha−1 nitrogen (N) was applied at planting on (i) corn yield, N uptake, removal, and balance; (ii) N2O emissions and NO3-N leaching; (iii) yield-scaled N2O emissions and NO3-N leaching during two corn growing seasons. We also evaluated factors influencing N2O emissions and NO3-N leaching via principal component analysis. Corn grain yield was higher in RT (8.4 Mg ha−1) than NT (6.2 Mg ha−1), reflectingmore available N in the soil in RT than NT, possibly due to the favorable aeration and increased soil temperature in deeper soil layers resulting from tillage. Hairy vetch increased corn grain yield and soil N. However, it led to higher losses of both N2O-N and NO3-N, indicating that increased corn grain yield, due to the hairy vetch’s N contribution, also resulted in higher N losses. Yield-scaled N2O-N emissions in NT-2019 (3696.4 g N2O-N Mg−1) were twofold higher than RT-2019 (1872.7 g N2O-N Mg−1) and almost fourfold higher than NT-2021 and RT-2021 indicating in a wet year like 2019, yield-scaled N2O-N emissions were higher in NT than RT. Principal component analysis indicated that NO3-N leaching was most correlated with soil N availability and corn grain yield (both positive correlations). In contrast, due to the continued presence of soil N, soil N2O-N fluxes were more driven by soil volumetric water content (VWC) with a positive correlation. We conclude that in soils with claypan and fragipans in humid climates, NT is not an effective strategy to decrease N2O-N fluxes. Hairy vetch benefits corn grain yield and supplements N but increases N loss through NO3-N leaching and N2O-N emissions.

Soil metagenomics reveals reduced tillage improves soil functional profiles of carbon, nitrogen, and phosphorus cycling in bulk and rhizosphere soils

Conservation tillage practices (CAT) are known to benefit soil health and soil ecosystem functions relative to conventional tillage (CVT); however, much uncertainty remains concerning microbial functional traits and their subsequent effects on soil nutrients under different tillage practices. We analyzed the functional profiles of the C, N, and P cycles in response to CAT of no-tillage (NT), reduced tillage (RT), and CVT of moldboard plowing (MP) in bulk and rhizosphere soils using shotgun sequencing. CAT induced distinct microbial functional patterns relative to CVT, and these differences were generally more evident in rhizosphere soils than in bulk soils. CAT promotes multiple metabolic pathways such as C and N decomposition, fermentation, CO oxidation, N fixation, nitrate reduction and inorganic-P and organic-P transformations in bulk and/or rhizosphere soils. Variations in these metabolic pathways were mainly driven by Bradyrhizobium, Mesorhizobium, Nitrososphaera, Phenylobacterium, Rhizobium which are affiliated with Proteobacteria, Actinobacteria, Acidobacteria, Bacteroidota and Thaumarchaeota. Furthermore, 24 high-quality metagenome-assembled genomes (MAGs) were reconstructed, of which three novel MAGs (TL100, TL46, and TL57) harbored functional genes regulating all metabolic pathways. In particular, NT-enriched MAGs (such as Sphingomonas) promote fermentation, resulting in the reduction of soil total carbon (TC) relative to MP in bulk soils. RT retained the contents of soil TC and total nitrogen (TN) well and up-regulated the phoR gene carried by Streptomyces, which promoted the regulation of P-starvation concomitantly with the increase in the contents of total phosphorous (TP) and available phosphorous (AP) in bulk soil. Additionally, assimilatory nitrate reduction coupled with organic-P mineralization was facilitated by CAT in rhizosphere soil, leading to the mitigation of N loss and the activation of soil organic-P for crop uptake. Overall, our results revealed that CAT significantly accelerated multiple metabolic potentials, and RT could sustain soil nutrient contents better than NT.

The LTAR Cropland Common Experiment at R. J. Cook Agronomy Farm.

Dryland agriculture in the Inland Pacific Northwest is challenged in part by rising input costs for seed, fertilizer, and agrichemicals; threats to water quality and soil health, including soil erosion, organic matter decline, acidification, compaction, and nutrient imbalances; lack of cropping system diversity; herbicide resistance; and air quality concerns from atmospheric emissions of particulate matter and greenhouse gases. Technological advances such as rapid data acquisition, artificial intelligence, cloud computing, and robotics have helped fuel innovation and discovery but have also further complicated agricultural decision-making and research. Meeting these challenges has promoted interest in (1) supporting long-term research that enables assessment of ecosystem service trade-offs and advances sustainable and regenerative approaches to agriculture, and (2) developing coproduction research approaches that actively engage decision-makers and accelerate innovation. The R. J. Cook Agronomy Farm (CAF) Long-Term Agroecosystem Research (LTAR) site established a cropping systems experiment in 2017 that contrasts prevailing (PRV) and alternative (ALT) practices at field scales over a proposed 30-year time frame. The experimental site is on the Washington State University CAF near Pullman, WA. Cropping practices include a wheat-based cropping system with wheat (Triticum aestivum L.), canola (Brassica napus, variety napus), chickpea (Cicer arietinum), and winter pea (Pisum sativum), with winter wheat produced every third year under the ALT practices of continuous no-tillage and precision applied N, compared to the PRV practice of reduced tillage (RT) and uniformly applied agrichemicals. Biophysical measurements are made at georeferenced locations that capture field-scale spatial variability at temporal intervals that follow approved methods for each agronomic and environmental metric. Research to date is assessing spatial and temporal variations in cropping system performance (e.g., crop yield, soil health, and water and air quality) for ALT versus PRV and associated tradeoffs. Future research will explore a coproduction approach with the intent of advancing discovery, innovation, and impact through collaborative stakeholder-researcher partnerships that direct and implement research priorities.

Evaluating Maize Residue Cover Using Machine Learning and Remote Sensing in the Meadow Soil Region of Northeast China

The management of crop residues in farmland is crucial for increasing soil organic matter and reducing soil erosion. Identifying the regional extent of crop residue cover (CRC) is vital for implementing conservation tillage and formulating agricultural subsidy policies. The Google Earth Engine (GEE) and remote sensing images from 2019 to 2023 were used to obtain spectral characteristics before the maize seedling stage in Northeast China, followed by constructing the CRC estimation models using machine learning algorithms. To avoid the impact of multicollinearity among data, three machine learning algorithms—ridge regression (RR), partial least squares regression (PLSR), and least absolute shrinkage and selection operator (LASSO)—were employed. By comparing the accuracy of these methods, the most accurate model was determined and applied to subsequent CRC estimation. Based on the estimated CRC and Conservation Technology Information Center definitions of tillage practices, the conservation tillage mapping was completed, and the spatiotemporal distribution characteristics were thoroughly analyzed. The following findings were demonstrated: (1) the PLSR-based model outperformed RR (Pearson’s correlation coefficient (r) = 0.8875, R2 = 0.7877, RMSE = 6.99%) and LASSO (r = 0.8903, R2 = 0.7926, RMSE = 6.88%) with higher accuracy (r = 0.9264, R2 = 0.8582, RMSE = 4.93%). (2) Over the five years, the average no-tillage (NT) proportion in the study area was 15.9%, reduced tillage (RT) was 17.8%, and conventional tillage (CT) was 66.3%. In 2020 and 2022, NT rates were significantly higher at 27.5% and 15.5%, while RT were 15.7% and 30.0%, respectively. (3) Compared to the Sanjiang and Liaohe Plains (RT = 1907 km2 and 1336 km2, and NT = 559 km2 and 585 km2, respectively), the Songnen Plain exhibited higher conservation tillage rates (where RT was 3791 km2 and NT was 1265 km2). This provides crucial scientific evidence for the management and planning of conservation tillage, thereby optimizing farmland production planning, enhancing production efficiency, and promoting the development of sustainable agricultural production systems.

Carbon sequestration through conservation tillage in sandy soils of arid and semi-arid climates: A meta-analysis

This meta-analysis assessed soil organic carbon (SOC) percent changes in sandy soils, transitioning from conventional tillage (CT) to conservational tillage (CST) in arid and semi-arid climates. High levels of SOC in sandy soils are difficult to attain especially when precipitation levels are very low, contributing to low biomass production, and increased decomposition of organic matter. While CT practices are known to reduce SOC through the breakdown of soil aggregates, accelerated decomposition of soil organic matter, and promote erosion, CST methods (i.e., mulch tillage, no tillage, reduced tillage, ridge tillage, etc.) offer the potential to preserve soil aggregates and increase SOC concentration. Analyzing 55 peer-reviewed publications in arid and semi-arid climates with ≥ 45 % sand content, this study compared SOC content between CST and CT over short- and long-term periods (349 paired observations). Results showed that CST increased SOC in sandy soils, with an estimated 12.74 ± 1.46 % increase. Specifically, reduced tillage (RdT), mulch tillage (MchT), and no tillage (NT) exhibited the highest increases of SOC by 18.94 ± 2.48 %, 11.45 ± 2.46 %, and 10.06 ± 2.46 %, respectively, compared to CT. Studies with durations of up to 15 years (n = 297) showed a progressive increase in SOC concentrations under CST; however, the long-term stability of the accrued carbon content in sandy soils of arid and semi-arid climates is still uncertain, as studies extending beyond 15 years (n = 52) did not demonstrate significant changes in SOC levels. CST significantly raised SOC concentrations in precipitation up to 600 mm, though no significant changes were observed for precipitation over 600 mm. In soils with over 56 % sand content, CST increased SOC by approximately 13 %. This study highlights both positive and limited impacts of CST practices for soil conservation and climate change mitigation, emphasizing their significance for both existing agricultural areas in arid regions and those in parts of the world where aridity is on the rise.

Fertility and tillage intensity affect weed community diversity and functional structure in long-term organic systems.

Knowledge of how agricultural management interacts with weed seed banks and emergent weed communities is crucial for proactive weed management. Though studies have detailed how differences in disturbance and nutrient applications between organic and conventional herbicide-based systems affect weed communities, few have focused on these same factors in contrasting organic systems. This study assessed the seed banks and emergent weed communities from the most recent crop rotation cycle (2017-2022) of a long-term experiment, which compared four organic grain and forage cropping systems differing in nutrient inputs and soil disturbance. The high fertility (HF) system received high-rate nutrient applications, low fertility (LF) received low-rate applications, enhanced weed management (EWM) focused on weed control through frequent soil disturbance, and reduced tillage (RT) prioritized soil health with less intense or frequent soil disturbance. Soil samples for greenhouse germination assays were collected at the beginning (2017) and end (2022) of the rotation to explore how these four systems influenced seed bank dynamics over time. Weed community biomass was also sampled in each crop during this time. Treatment effects on weed abundance, taxonomic diversity, and community-weighted means and functional dispersion of weed traits were analyzed with generalized mixed-effect models. The RT system had the highest weed seed bank taxonomic diversity, and EWM had the lowest. RT and LF had higher functional dispersion of traits than HF in the seed bank. Weed seed bank communities in HF and RT were characterized by short, small-seeded, and early germinating weed species. However, seed banks were also labile: Differences between systems in seed density and all other mean trait values were dependent on the crop, which preceded seed bank sampling. Likewise, differences among emergent weed communities in the four systems depended on an interaction between crop species and their planting year. Results suggest that resource availability and intensity of disturbance act as weed community assembly filters in organic cropping systems. Organic growers seeking to design systems that balance weed management and production goals can use relatively low soil disturbance and nutrient application to increase weed community taxonomic or functional diversity without necessarily increasing weed biomass or seed bank density.

Long‐term effects of management practices on soil water, yield and water use of dryland wheat: A global meta‐analysis

AbstractSoil water conservation in dryland agriculture mainly depends on precipitation. We chose 35 long‐term experiments and analysed the data by using meta‐analysis to check how fallow management methods affect soil water storage of dryland winter wheat planting (SWS), precipitation storage efficiency (PSE), crop yield and water use efficiency (WUE). No‐tillage (NT), compared to conventional tillage (CT) in the fallow period, increased PSE, SWS, grain yield and WUE by 32.9%, 27.1%, 30.5% and 22.6%, respectively. Reduced tillage (RT) and subsoil tillage (ST) increased PSE by 15.2% and 11.7%, SWS by 17.4% and 15.0% and grain yield by 15.5 and 13.8%, respectively, but these had a non‐significant effect on WUE. The conservation tillage methods interacted significantly with the residue management and fallow mulching practices. Compared to CT, the conservation tillage methods with fallow mulching increased PSE, SWS, grain yield and WUE, but the growing of cover crops (designated as biological mulching) decreased PSE, SWS and grain yield by 17.3%, 13.0% and 32.0%, and had a non‐significant impact on WUE. Under the condition of straw mulching, NT increased PSE, SWS, grain yield and WUE by 43.7%, 38.1%, 40.6% and 42.9%, respectively, compared to CT. NT and RT increased the PSE, SWS and WUE, under normal mean annual precipitation (MAP), however, ST increased these observations under wet MAP, compared to CT. The effects of tillage methods varied with soil texture, and they were highly interrelated with water conservation, wheat yield and water use. We conclude that compared to conventional tillage, the conservation tillage methods increased soil water conservation during the fallow period, which increased wheat yield and water use. Moreover, NT with or without residue retention increased the fallow water conservation and wheat yield. Crop residues should be retained while applying RT and ST to grow winter wheat in dryland regions.

Conservation tillage enhances the sequestration and iron-mediated stabilization of aggregate-associated organic carbon in Mollisols

Conservation tillage practices, which involve minimal or no soil disturbance and crop residue retention, are known to help preserve soil organic carbon (SOC). However, the mechanisms underlying the minerals-mediated chemical and physical stabilization of SOC remain unclear. Here, a long-term field experiment was initiated in 2012 to investigate the effects of tillage managements on the contents and chemical composition of SOC density fractions, iron oxides transformation and aggregate stability in Mollisols. We utilized three treatments: conventional tillage (CT) without crop residue, reduced tillage (RT) and no tillage (NT) with straw mulching. Compared to CT, RT and NT significantly increased SOC content by 13.6 % and 17.9 % in the 0–20 cm soil layer due to an increase in the aromatic compound contents. Furthermore, NT and RT increased the mean weight diameter by 17.7 % and 10.7 %, respectively, indicating increased aggregate stability compared to CT. Additionally, the contents of amorphous iron oxides (Feo) and complex iron oxides (Fep) increased under NT and RT by 10.6–14.4 % and 12.7–41.1 %, respectively, in bulk soil and silt + clay fractions within macroaggregates (>0.25 mm). The contents of Feo and Fep were strongly positively correlated with aggregate stability (p < 0.001, r2 = 0.64), and promote the physical protection of SOC. Both NT and RT enhanced the aromatic-C content and aromatic-C/aliphatic-C ratio by 13.6 %–24.6 % and 16.5 %–38.9 % in macroaggregates compared with CT. Moreover, the aromatic-C/aliphatic-C ratio increased with increasing Feo plus Fep contents (p < 0.001, r2 = 0.73), which led to an increased in the recalcitrant-C proportion, and this shift was benefit for the accumulation of mineral-associated OC. These results indicate that long-term conservation tillage can augment the accessibility of Fe for binding C, possibly by forming organo-Fe complexes, which subsequently improve soil aggregation, and thus promoted the chemical stability and long-term sequestration of SOC in Mollisols of Northeast China.

Soil Microbial Functions Linked Fragrant Rice 2-Acetyl-1-Pyrroline with Soil Active Carbon Pool: Evidence from Soil Metagenomic Sequencing of Tillage Practices

Improved tillage management in fragrant rice cropping systems can enhance soil organic carbon (SOC) and the content of 2-Acetyl-1-Pyrroline (2-AP), a crucial volatile compound contributing to the aroma of fragrant rice. Despite this, the interplay between 2-AP content in fragrant rice and SOC metabolism, alongside the influences exerted by soil microbial functions, remains poorly understood. This study introduces a comprehensive 6-year field experiment which aims to correlate SOC with rice grain 2-AP content by analyzing soil microbial KEGG functions, such as carbon and amino acid metabolism, using metagenomic sequencing. The experiment assessed three tillage practices, conventional tillage (CT), reduced tillage (RT), and no tillage (NT), with soil samples collected on three dates in 2022. The results indicated that NT significantly (p &lt; 0.05) enhanced SOC content and modified carbon metabolism by upregulating the Calvin cycle (K01601) and reducing hemicellulose degradation (K01710). Additionally, NT notably increased the soil levels of alkaline amino acids, such as histidine and ornithine, which were 165.17% and 1218.42% higher, respectively, than those in CT, possibly linked to an increase in soil pH. Furthermore, the 2-AP content in fragrant rice under NT was significantly higher by 52.02% and 13.90% compared to under RT and CT, respectively. NT also upregulated K00250 (alanine, aspartate, and glutamate metabolism) and K00290 (valine, leucine, and isoleucine biosynthesis), leading to significantly higher levels of 2-AP biosynthesis-related amino acids proline and glutamate in fragrant rice grain. This study links SOC and 2-AP biosynthesis via soil microbial functions, presenting a novel strategy for improving the quality of fragrant rice through soil management practices.

Bacterial functions are main driving factors on paddy soil organic carbon in both surface soil and subsoil

Subsoil contains a significant amount of soil organic carbon (SOC) in rice paddies, playing a crucial role in global carbon (C) cycling. However, the mechanisms driving SOC dynamics in topsoil and subsoil remain elusive, as the vertical distribution of soil microbes and their associated functions varies. In our study, we explored the linkages between SOC dynamics and microbial functions across different soil depths (0–10 cm for topsoil, and 10–20 and 20–30 cm for subsoil) within a framework of contrasting tillage managements, including conventional tillage (CT), reduced tillage (RT), and no-tillage (NT). In the topsoil, bacterial biosynthesis and degradation functions negatively contributed (P < 0.05) to SOC accumulation, whereas in the subsoil layers, these functions exhibited a positive effect. Notably, both partial least squares path modeling (PLSPM) and stepwise regression showed that bacterial biosynthesis and degradation functions exert a stronger influence on SOC accumulation than fungal functions. Metagenomic sequencing revealed that the cellulose degradation (K01179) and reductive tricarboxylic acid cycle (rTCA cycle) (K00174 and K00175) were main factors driving SOC variation in topsoil. Starch degradation (K00705 and K01187) and rTCA cycle (K00175 and K00031) contributed to 93 % of the SOC variation in subsoil. Therefore, the rTCA cycle contributed to SOC variation in paddy soil across 0–30 cm soil profile. Moreover, tillage management could influence the abundances of enzymes associated with starch degradation and rTCA cycle. The contrasting driving factors influencing SOC in topsoil and subsoil could be associated with soil microbial functions, which would response differently to tillage managements.

Soil tillage reduction as a climate change mitigation strategy in Mediterranean cereal‐based cropping systems

AbstractAccording to climate change projections, global temperatures would increase by 2°C by 2070, and agriculture is expected to be among the most affected sectors, particularly intensive field crops like cereals. Therefore, researchers need to investigate the most cost‐effective agricultural strategies that can prevent production losses and ensure global food security. This study aimed to identify the limiting factors of durum wheat (Triticum turgidum L. subsp. Durum (Desf.) Husn.) yield production under Mediterranean conditions. Durum wheat yield data of over 5 years (2017–2022), from a 30‐year rainfed long‐term experiment conducted in the ‘Pasquale Rosati’ experimental farm of the Polytechnic University of Marche in Agugliano, Italy (43°32’ N, 13°22′ E, 100 a.s.l.) on Calcaric Gleyic Cambisols with a silt‐clay texture, were analysed and compared with the recorded thermo‐pluviometric trend. The field trial included two soil managements (no tillage vs. conventional tillage) and three Nitrogen (N) fertilization levels (0, 90, and 180 kg N ha−1). The most important driver for durum wheat production was N fertilization. However, in the absence of N fertilization, no tillage showed a higher yield (+1.2 t ha−1) than conventional tillage due to the accumulation of organic matter in the soil. When wheat was fertilized with 90 kg N ha−1, no tillage resulted in 25% yield more than conventional tillage (+1.2 t ha−1), but this occurred only when the increase in temperatures was constant from January until harvest (this happened in 3 of 5 years of monitoring). The non‐constant increase in temperature from January to wheat harvest may hamper crop phenological development and reduce the potential yield. The highest fertilization rate (180 Kg N ha−1) resulted in the highest wheat yields regardless of soil management and thermo‐pluviometric trends (5.78 t ha−1). After N fertilization and soil management, the minimum and maximum temperature in February and the maximum temperature in April were crucial for durum wheat production under Mediterranean condition. When there is non‐constant increase in temperature from January to wheat harvest no‐tillage should be preferred over conventional tillage because wheat yields did not reduce under no tillage. Thus, agricultural policies that support the switch from conventional tillage to no‐tillage management should be promoted to enable food security in Mediterranean environments.

Assessment of techno-economic feasibility of conservation agriculture planter for planting of soybean in south coastal region of Bangladesh

Assessment of techno-economic feasibility of conservation agriculture planter for planting of soybean in south coastal region of Bangladesh

Influence of the Long-Term Application of Management Practices (Tillage, Cover Crop and Glyphosate) on Greenhouse Gas Emissions and Soil Physical Properties

Soil treatments have a significant influence on the agricultural and environmental productivity of agricultural practices. Arable lands are one of the sources of greenhouse gas emissions (GHG) that are influenced by the chemical and physical properties of the soil and are an essential contributor to climate change. We aim to evaluate the long-term management of agricultural practices, such as different tillage systems, cover crops, and glyphosate, on GHG emissions and soil physical properties. The field trial involved three tillage systems (conventional tillage (CT), reduced tillage (RT), and no-tillage (NT)), along with variations in cover cropping (with and without cover crops) and glyphosate application (with and without glyphosate). These treatments were implemented during the cultivation of oilseed rape in 2022 as part of a cropping sequence consisting of five crops: winter wheat; winter oilseed rape; spring wheat; spring barley; and field pea. Greenhouse gas emissions (carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O)) were directly measured using a closed static chamber system. Through the examination of these management techniques, the soil’s physical properties over the studied period were assessed for their impact on GHG fluxes. The findings of the study reveal that N2O emissions were relatively low during the first month of measurement, with significant differences (p &lt; 0.05) observed in the interaction between cover crop and glyphosate treatments. Additionally, N2O emissions were notably elevated in the reduced (0.079 µg m−2 h−1) and conventional tillage (0.097 µg m−2 h−1) treatments at the second month of measurement. Regarding CH4, increased emissions were observed in the reduced tillage and cover crop treatments. CO2 emissions exhibited variability across all of the investigated treatments. Notably, GHG fluxes spiked at the second measurement, signifying the maximum uptake of nutrients by the main plants during the growth phase. Greenhouse gas emissions leveled off across all of the treatments following the harvest, marking the end of the cultivation period. The influence of the deployed techniques varied across the determined physical parameters of the soil. The incorporation of cover crops contributed to improved water content and, further, to electrical conductivity. Glyphosate use showed no direct impact on physical properties of the soil while the different tillage treatments had varying effects on the distribution of the physical properties of the soil with respect to the degree of disturbance or tillage-induced changes. Additionally, GHG emissions were strongly correlated with precipitation at one week and two weeks before sampling, except for CO2, which showed a weaker correlation at two weeks before GHG sampling. The findings indicate that reduced and conventional tillage methods might adversely affect greenhouse gas emissions and plant functionality, particularly concerning nutrient release and uptake, especially in temperate climate conditions.

Rhizome fragment weight and density of competing shoots determine belowground regrowth of Elymus repens

AbstractManagement of perennial weeds has become increasingly complex with the reduction of herbicide use and tillage. Their capacity to store nutrients into vegetative organs and to regenerate to establish new individuals makes them very persistent and hard to control. A key aspect for managing perennial weeds is to minimise storage reserves to reduce vegetative regeneration. For that prospect, better knowledge of the regrowth capacities from storage organs is needed. Our work focused on the mechanistic understanding of belowground regrowth dynamics from fragments of Elymus repens rhizomes by analysing the effect of source and sink factors. The effect of rhizome fragment weight (i.e., source) and the number of regrowing buds and belowground shoots (i.e., sinks) was assessed for four mechanisms: sprouting, belowground shoot elongation, belowground shoot biomass to length conversion and biomass allocation to belowground shoots versus roots. Heavier fragments contributed to faster sprouting, faster belowground shoot elongation and increased the proportion of remobilised biomass allocated to belowground shoots. Higher belowground shoot density increased the proportion of remobilised biomass allocated to belowground shoots but decreased individual elongation rate. In other words, larger reserves resulted in a better regeneration capacity and a higher number of growing belowground shoots increased the competition for reserves among them. The belowground shoot that sprouted first on a fragment grew faster and dominated the other shoots on the same fragment. Dominant belowground shoots were located toward the apical end of the fragment. These findings support the fact that tillage should aim at cutting storage organs into the smallest fragments possible to reduce regeneration capacity. This study also emphasised that belowground regrowth mechanisms are complex, and further studies should investigate other species with different types of storage organs.

Comparison of the effects of five long‐term land use and management practices on runoff, soil erosion, and nutrient loss under natural rainfall in the Mollisol region of Northeast China

AbstractClarifying the effects of various land‐use and management practices on soil erosion and nutrient loss of sloping land can help optimize land use patterns and management strategies. This study assessed the effects of five long‐term land‐use and management practices on runoff, soil erosion, and nutrient losses. Field data from runoff plots established in 2006 in bare land (BL), natural vegetation restoration (NVR), no tillage (NT), reduced tillage (RT), and conventional tillage (CT) were used in two seasons of natural rainfall (from July to September in 2021 and 2022). The results indicated that the runoff depth (RD) was 84.1% and 43.2%–81.7% lower, the sediment yield (SY) was 99.9% and 96.9%–99.8% lower, the total nitrogen (TN) loss was 99.1% and 93.1%–98.6% lower, and the total phosphorous (TP) loss was 99.8% and 96.7%–99.7% lower in the NVR and three tillage practices, respectively than in the BL. The RD, SY, and nutrient losses were significantly lower in NT than in RT and CT. The TN loss in runoff contributed to 88.3% and 87.6% of the TN loss in the NVR and NT, respectively, whereas the TN loss in the sediment (TN‐SL) for BL accounted for 94.7% of the TN loss in BL. Meanwhile, most of the TP loss (56.1%–99.7%) was attributed to soil erosion rather than runoff in the five treatments. Furthermore, the effect of runoff and SY on nutrient losses differed significantly for the five land‐use and management practices. The effects of runoff and SY on the TP loss were negligible in the NVR and three tillage treatments. However, the effects on the TN loss were larger. Rainfall erosivity had the largest effect on runoff, SY, and nutrient loss in the five treatments. Our findings can help land managers to select sustainable measures to control soil and nutrient losses in sloped farmland in Northeast China.

Predicting the spatial variation in cost-efficiency for agricultural greenhouse gas mitigation programs in the U.S.

BackgroundTwo major factors that determine the efficiency of programs designed to mitigate greenhouse gases by encouraging voluntary changes in U.S. agricultural land management are the effect of land use changes on producers’ profitability and the net sequestration those changes create. In this work, we investigate how the interaction of these factors produces spatial heterogeneity in the cost-efficiency of voluntary programs incentivizing tillage reduction and cover-cropping practices. We map county-level predicted rates of adoption for each practice with the greenhouse gas mitigation or carbon sequestration benefits expected from their use. Then, we use these bivariate maps to describe how the cost efficiency of agricultural mitigation efforts is likely to vary spatially in the United States.ResultsOur results suggest the combination of high adoption rates and large reductions in net emissions make reduced tillage programs most cost efficient in the Chesapeake Bay watershed or the Upper Mississippi and Lower Missouri sub-basins of the Mississippi River. For programs aiming to reduce net emissions by incentivizing cover-cropping, we expect cost-efficiency to be greatest in the areas near the main stem of the Mississippi River within its Middle and Lower sections.ConclusionsMany voluntary agricultural conservation programs offer the same incentives across the United States. Yet spatial variation in profitability and efficacy of conservation practices suggest that these uniform approaches are not cost-effective. Spatial targeting of voluntary agricultural conservation programs has the potential to increase the cost-efficiency of these programs due to regional heterogeneity in the profitability and greenhouse gas mitigation benefits of agricultural land management practices across the continental United States. We illustrate how predicted rates of adoption and greenhouse gas sequestration might be used to target regions where efforts to incentivize cover-cropping and reductions in tillage are most likely to be cost -effective.

Influence of Planting Techniques and Integrated Nutrient Management on Soil Health in Rice (Oryza sativa L.)

The study investigated the impact of different planting techniques and nitrogen management at Sardar Vallabhbhai Patel University of Agriculture &amp; Technology, Meerut (UP) during the rainy (kharif) season of 2019-20 on soil health in rice. Soil samples were collected at two depths, air-dried, and analyzed for aggregate size distribution using wet sieving. Particulate organic carbon (POC) was determined through aggregate slaking, while total organic carbon (TOC) content was assessed using rapid titration. Microbial biomass carbon (MBC) was calculated by incubating soil samples, followed by fumigation-extraction methods. Results revealed that soil pH and electrical conductivity remained unaffected by planting techniques and fertility levels. Aggregate size distribution analysis revealed that the Furrow Irrigated Raised Bed (FIRB) treatment promoted larger macro-aggregates (&gt;2mm) at varying soil depths, while Conventional Tillage (CT) encouraged smaller micro-aggregates. Reduced Tillage (RT) combined with Farmyard Manure (FYM) and chemical fertilizer increased POC and TOC content, emphasizing the importance of reduced soil disturbance and organic matter addition. Conversely, CT exhibited lower POC and TOC levels due to intensive soil disturbance. RT with FYM and chemical fertilizer significantly enhanced soil MBC, highlighting their role in improving soil health and fertility.

X-ray computed tomography – Measured pore characteristics and hydro-physical properties of soil profile as influenced by long-term tillage and rotation systems

Soil hydro-physical properties and pore characteristics are crucial for crop production as they determine water, air, and nutrients transfer. Long-term tillage and crop rotation studies provide valuable insights into the effects of management practices on various soil properties. Because of the inherent differences between the surface and sub-surface soils, the impact of management systems can be pronounced differently at different soil depths. Though many studies have reported the tillage and rotation effects on soil hydro-physical properties, their vertical impacts to a depth of 40 cm were less explored. This study aims to assess the impact of long-term tillage and crop rotations on soil hydro-physical properties and pore characteristics to a depth of 40 cm utilizing the X-ray Computed Tomography (XCT) technique. Intact soil cores of 7.6 cm height × 7.6 cm ∅ were collected from tillage [no-till (NT); reduced-till (RT); conventional-till (CT)] and crop rotation [continuous corn (CC) – Zea mays L. and corn-soybean (CS) – Glycine max [Merr.] L.] plots of 0–40 cm depth (each sample for 10 cm increment). The XCT scanning allowed us to investigate the soil pore size distribution, porosity, number of branches, and average branch length. Measured hydro-physical properties in the study include bulk density (ρb), plant available water content (PAW), saturated hydraulic conductivity (Ksat), and water retention. XCT image analysis revealed that NT with CC/CS rotation increased the number of macropores at surface and sub-surface depths. However, the number of mesopores was higher with NT × CS. In addition, NT lowered the ρb by 9.6 % and increased the PAW by 28 % compared to the CT. Ksat was higher under NT × CS at 0–10 cm and had a strong positive correlation with the XCT-measured number of macropores. Therefore, we conclude that NT with CS rotation can potentially improve soil pore characteristics and hydro-physical properties, leading to enhanced soil function.

A comprehensive analysis of resource conservation strategies: Impacts on productivity, energetics, and environmental footprints in rice-based systems of the Eastern Indo-Gangetic Plains

In Eastern Indo-Gangetic Plains, traditional rice-wheat cropping system, reliant on wet puddling for rice and conventional tillage for wheat, has led to the soil degradation and stagnant yields, highlighting the need for sustainable practices. A field experiment (2018–2021) evaluated the impacts of tillage and residue management on productivity, energy efficiency, and soil health across three cropping systems: rice-wheat (RW), rice-maize (RM), and rice-chickpea (RC). Three tillage practices-conventional tillage (CT), reduced tillage (RT), and reduced tillage with 30 % residue retention (RTR30) were arranged in a randomized block design. The results showed that partial conservation agriculture (pCA) practices significantly enhanced the system productivity, with RM under RT achieving the highest yield (12.2 Mg ha−1). Reduced tillage consistently the minimized energy use, while pulses-based systems had the highest energy ratio (3.97). On average, total earthworm counts were 0.92 and 6.5 times higher during the rainy and post-rainy seasons in pCA treatments in comparison to CT. Earthworm species diversity was more in pCA-based production systems (RT/RTR30) than in CT. In rice-wheat cropping system, maximum bacterial and actinomycetes counts were observed in CT/FP followed by pCA production system. Maize-based systems under CT had the highest global warming potential, while the pulse-based systems had the lowest. The RM cropping system under RTR30 demonstrated the greatest increase in the soil organic carbon. In conclusion, adopting pCA management practices and incorporating the pulses can improve crop productivity, soil health, and sustainability, offering a promising path for enhancing food and nutritional security in rice-based production systems.