No-till Soil Research Articles

Applying a Comprehensive Model for Single-Ring Infiltration: Assessment of Temporal Changes in Saturated Hydraulic Conductivity and Physical Soil Properties

Modeling agricultural systems, from the point of view of saving and optimizing water, is a challenging task, because it may require multiple soil physical and hydraulic measurements to investigate the entire crop cycle. The Beerkan method was proposed as a quick and easy approach to estimate the saturated soil hydraulic conductivity, Ks. In this study, a new complete three-dimensional model for Beerkan experiments recently proposed was used. It consists of thirteen different calculation approaches that differ in estimating the macroscopic capillary length, initial (θi) and saturated (θs) soil water contents, use transient or steady-state infiltration data, and different fitting methods to transient data. A steady-state version of the simplified method based on a Beerkan infiltration run (SSBI) was used as the benchmark. Measurements were carried out on five sampling dates during a single growing season (from November to June) in a long-term experiment in which two soil management systems were compared, i.e., minimum tillage (MT) and no tillage (NT). The objectives of this work were (i) to test the proposed new model and calculation approaches under real field conditions, (ii) investigate the impact of MT and NT on soil properties, and (iii) obtain information on the seasonal variability of Ks and other main soil physical properties (θi, soil bulk density, ρb, and water retention curve) under MT and NT. The results showed that the model always overestimated Ks compared to SSBI. Indeed, the estimated Ks differed by a factor of 11 when the most data demanding (A1) approach was considered by a factor of 4–8, depending on the transient or steady-state phase use, when A3 was considered and by a practically negligible factor of 1.0–1.9 with A4. A relatively higher seasonal variability was detected for θi at the MT than NT system. Under both MT and NT, ρb did not change between November and April but increased significantly until the end of the season. The selected calculation approaches provided substantially coherent information on Ks seasonal evolution. Regardless of the approach, the results showed a temporal stability of Ks at least from early April to June under NT; conversely, the MT system was, overall, more affected by temporal changes with a relative stability at the beginning and middle of the season. These findings suggest that a common sampling time for determining Ks could be set at early spring. Soil management affected the soil properties, because the NT system was significantly wetter and more compact than MT on four out of five dates. However, only NT showed a significantly increasing correlation between Ks and the modal pore diameter, suggesting the presence of a relatively smaller and better interconnected pore network in the no-tilled soil. This study confirms the need to test infiltration models under real field conditions to evaluate their pros and cons. The Beerkan method was effective for intensive soil sampling and accurate field investigations on the temporal variability of Ks.

Effect of long-term liquid dairy manure application on activity and structure of bacteria and archaea in no-till soils depends on plant in development.

This study aimed to evaluate the impact of long-term liquid dairy manure (LDM) application on the activity and structure of soil bacterial and archaea communities in two cropping seasons over 1year of a no-till crop rotation system. The experiment was run in a sandy clay loam texture Oxisol, in Brazil, including LDM doses of 60, 120, and 180 m3ha-1year-1, installed in 2005. Soil sampling was conducted during spring 2018 and autumn 2019 at 0-10-cm depth. Microbial biomass carbon and nitrogen, 16S rRNA gene sequencing, microbial respiration and quotient were performed. Over the 14-year period, LDM application increased soil microbial community activity. Analysis of 16S rRNA gene sequencing revealed dominance by Proteobacteria, Acidobacteria, and Actinobacteria phyla (67% in spring and 70% in autumn). Genera Pirulla and Nitrososphaera showed enrichment at LDM doses of 120 and 180 m3ha-1year-1 doses, respectively. During spring, following black oat cropping, shifts in the relative abundance of Bacteroidetes, Proteobacteria, Firmicutes, Gemmatimonadetes, Verrucomicrobia, Chloroflexi, Actinobacteria, and AD3 phyla were observed due to LDM application, correlating with soil chemical indicators such as pH, K, Ca, Mn, and Zn. Our findings indicate that plant development strongly influences microbial community composition, potentially outweighing the impact of LDM. Our findings indicate that the application of liquid dairy manure alters the soil bacterial activity and community; however, this effect depends on the developing plant.

Sowing depth stability analysis and test verification of no-tillage planter parallel 4-bar row unit

The sowing depth stability and consistency of the no-tillage planter, particularly the high-speed operation, are poor. A reason for this is that the structure and parameter selection of no-tillage planter row unit profiling mechanism are unreasonable. The stability and consistency of sowing depth is beneficial when the upper and lower links of the parallel 4-bar profiling mechanism (PFPM) are parallel to the ground, but this principle is not satisfied on the uneven no-till soil. To improve the stability of gauge wheels downforce (GWD) and sowing depth of no-tillage planter row unit. The variation law of spring additional downforce (SAD) with tilt angle of parallel 4-bar profiling mechanism (PFPM) and connection offset of spring is discussed by constructing the steady state analysis matrix equation of PFPM. Additionally, the influence of tilt angle of PFPM and SAD on the stability of the sowing depth was analyzed. Based on the single factor control variable test method, bench and field tests were conducted. The test results show that the SAD increases nonlinearly with the increase in the degree of tilt of PFPM from downward to upward. Under the condition that four springs are installed and the tilt angle of PFPM is between (−20°–20°), the maximum SAD is 485.95 N, 1236.64 N, and 2258.05 N when the spring connection offset is 44 mm, 79 mm, and 115 mm, respectively. When the tilt angle is 8° upward, the GWD increases by 429 N, 575 N, and 984 N, GWD stability increases by 42.31 %, 56.16 %, and 50.29 %, and ditching depth stability increases by 30.00 %, 12.50 %, and 30.00 % compared with that of the control group at the sowing speed of 8, 10, and 12 km/h, respectively. At the sowing speed of 10 km/h, when the PFPM is operated with spring-free and additional springs, the average GWD increases by 353 N, and the stability of GWD and ditching depth increases by 34.38 % and 20.00 %, respectively. The results showed that the tilt upward of PFPM and SAD were beneficial to improve the stability of the GWD and sowing depth of the no-tillage planter row unit. The results not only verify the correctness of theoretical analysis, but also provide theoretical basis for the design and application adjustment of high-speed no-tillage planter.

Strategic tillage of no-till decreased surface and subsurface losses of dissolved phosphorus.

Enrichment of soluble P on the surface layer of long-term no-till (NT) soils, and consequent increase in dissolved P losses, is a concern for which occasional plowing has been suggested as a remedy. We measured the effect of such strategic tillage (ST) on surface and subsurface P losses from 0.5-ha field plots on clay soil for 4years. Two NT plots had discharged threefold dissolved molybdate-reactive P (DRP) losses compared to annually plowed soil conventional tillage (CT). ST by plowing to 20-cm depth was applied on one of the NT plots, whereas the other remained under NT. ST done in July was sown with canola (Brassica napus ssp. oleifera) to establish plant cover before winter. Summed 4-year DRP loss from ST treatment was 60% lower compared to NT (0.78vs. 1.96kg ha-1), accompanied with 11% higher particulate P (PP) loss (4.39vs. 3.97kg ha-1). CT plots produced slightly lower DRP losses (0.53-0.76kg ha-1) than ST, but higher PP losses (6.02-7.96kg ha-1). Bioavailable P (BAP) losses from ST were lower than from the other treatments if >7% of PP turns bioavailable. After ST, soil P stratification first vanished, but started to develop again when NT was resumed. Occasional tillage of NT soils mitigates DRP losses over several years, and it was at the study site the preferred mitigation option in reducing BAP losses.

Changes in the taxonomic composition of soil bacterial communities under different inter-row tillage managements in a sloping vineyard of the Balaton Uplands (Hungary).

The common grape (Vitis vinifera L.) has been cultivated for thousands of years. Nowadays, it is cultivated using a variety of tillage practices that affect the structure of the soil microbial communities and thus the health of the vine. The aim of this study was to explore and compare the effects of tillage (shallow tillage with bare soil) and no-tillage (perennial grass cover) practices on soil physical and chemical properties and soil bacterial community diversities in a small catchment. Soil samples were taken in July and October 2020 at different slope positions of two vineyards exposed to erosion. The two sampling sites were separated by the agricultural inter-row management type: tilled and no-tilled slopes. The taxonomic diversity of bacterial communities was determined using 16S rRNA gene-based amplicon sequencing method on Illumina MiSeq platform. Based on the examined soil properties, the sampling areas were separated from each other according to the positions of the upper and lower slopes and the sampling times. Both the tilled and no-tilled soil samples were dominated by sequences assigned to phyla Pseudomonadota, Acidobacteriota, Bacteroidota, Verrucomicrobiota, Actinobacteriota, and Gemmatimonadota. The results showed that tillage had no significant effect compared to the no-tilled samples in the studied area. Water runoff and seasonally changed soil physical and chemical properties affected mainly the bacterial community structures.

Microbial Proxies for Anoxic Microsites Vary with Management and Partially Explain Soil Carbon Concentration.

Anoxic microsites are potentially important but unresolved contributors to soil organic carbon (C) storage. How anoxic microsites vary with soil management and the degree to which anoxic microsites contribute to soil C stabilization remain unknown. Sampling from four long-term agricultural experiments in the central United States, we examined how anoxic microsites varied with management (e.g., cultivation, tillage, and manure amendments) and whether anoxic microsites determine soil C concentration in surface (0-15 cm) soils. We used a novel approach to track anaerobe habitat space and, hence, anoxic microsites using DNA copies of anaerobic functional genes over a confined volume of soil. No-till practices inconsistently increased anoxic microsite extent compared to conventionally tilled soils, and within one site organic matter amendments increased anaerobe abundance in no-till soils. Across all long-term tillage trials, uncultivated soils had ∼2-4 times more copies of anaerobic functional genes than their cropland counterparts. Finally, anaerobe abundance was positively correlated to soil C concentration. Even when accounting for other soil C protection mechanisms, anaerobe abundance, our proxy for anoxic microsites, explained 41% of the variance and 5% of the unique variance in soil C concentration in cropland soils, making anoxic microsites the strongest management-responsive predictor of soil C concentration. Our results suggest that careful management of anoxic microsites may be a promising strategy to increase soil C storage within agricultural soils.

Studying Methods of No-till in the Garabagh Plain

The research results are presented and a comparative assessment of the methods of no-till soil cultivation in the Karabakh Plain is given. The advantages and disadvantages of moldboard tillage, direct sowing and the effect of hoeing a plowed or milled field on the loss of NPK per 1 ha as a result of erosion were studied. The author concludes that direct seeding is one way to reduce erosion. This must be used along with other soil erosion control methods.

The influence of previous crops and tillage on available moisture reserves of chernozem typical for growing spring barley

The unstable yield of agricultural crops arises due to insufficient soil moisture supply at crucial moments of plant emergence and growth, complicating agriculture and exposing it to the risk of crop losses. The purpose of the study is to determine the impact of the soil tillage system and previous crops on the productivity of spring barley plants. This was a long-term stationary experiment (2021-2023) with the application of statistical data processing. The influence of four previous crops was investigated – grain maize (control), soybeans, winter rapeseed, and sunflower – and three main soil tillage methods. It is established that the highest significant moisture reserves in the 0-100 cm soil layer at the sowing period were formed when spring barley was placed after soybeans, exceeding the control variant (grain maize) by 3.2 mm in 2021, 3.6 mm in 2022, and 3.4 mm in 2023, and after winter rapeseed by 8.5 mm, 6 mm, and 5.7 mm, respectively, over the years. The use of shallow no-till cultivation provided an advantage over the control (ploughing) in all years of observation: by 2.2 mm in 2021, 1.8 mm in 2022, and 8.8 mm in 2023. During the sowing period of the studied crop, the control surpassed only surface no-till cultivation by 2.7 mm in 2022. The optimal option should be considered the combination of soybeans as a previous crop with shallow no-till soil cultivation at 14-16 cm, which ensured moisture reserves during the earing period of the crop in 2021 – 75.1 mm, in 2022 – 93.2 mm, and in 2023 – 92.2 mm, and at the time of harvest, these indicators were 60.7 mm, 67.3 mm, and 60.0 mm, respectively. The grain yield of spring barley under this option was the highest in the experiment, averaging 7.26 t/ha, which is 27.3% higher than the control. The results of the study can be used to realise the genetic potential of spring barley plants to form stable productivity

Long-term soil quality and C stock effects of tillage and cover cropping in a conservation agriculture system

Conservation and regenerative agriculture are widely considered as approaches aiming at addressing challenges in relation to climate change and soil quality. In that respect, no tillage (NT) and use of cover crops (CCs) are seen as key elements in achieving the sustainability goals of these approaches, but the long-term individual and interactive effects of these elements remain unknown. We examined the impact of tillage (NT and mouldboard ploughing) combined with a fodder radish CC in continuous cereal cropping. Soil was sampled in the 0–10 and 10–20 cm layer after two decades of treatments in the CENTS experiment at AU Viborg (Denmark) situated on a sandy loam with 9% clay. We assessed soil structural quality, SOC stocks, clay dispersibility (CD), wet stability of aggregates (WSA) and soil pore characteristics. Neither tillage nor cover cropping affected the SOC stock in the 0–20 cm soil layer. No tillage improved CD, WSA and plant available water capacity in 0–10 cm depth as compared to ploughing. The marked improvement in CD and WSA of NT soils could not be explained by SOC per se, but rather positive effects ascribed to absence of disturbance. In contrast, soil porosity, especially in 10–20 cm depth, the fraction of soil volume represented by >30 µm pores and gas diffusivity decreased, and NT soils resulted in a less good soil structural quality. The inclusion of CCs improved soil structural quality and the functionality of the soil macropore system. Hence, CCs have the potential to alleviate negative effects of NT on pore characteristics at macroscale. Furthermore, we found that the positive effects of NT on CD and WSA and of CCs on pore characteristics at macroscale were much more pronounced after long- (20 yrs NT; 13 yrs CC) than after medium-term (10 yrs NT; 5 yrs CC) underlining the value of long-term conservation agriculture experiments.

Soil organic matter thermal pools as influenced by depth, tillage, and soil texture – A Rock-Eval® analysis study on the cropland soils of the Swiss Plateau

This study investigated the relationships between the soil organic matter content (SOM), SOM thermal pools, soil properties, and tillage practices, on cropland soils of the central plateau of Switzerland. Soil samples were collected in 45 no-till and conventional tillage fields in five layers from 0 to 40 cm depth. Soil organic carbon content (SOC) and hydrocarbon compound (HC) pools were analysed with Rock-Eval® thermal analysis. In addition, the clay content was determined by sedimentation.The SOM contents were highest in 0–5 cm of no-till soils and the plough pan of tilled soils. SOM was less oxygenated and showed lower degradation under conventional tillage then no-tillage. The proportion of the thermo-stable pool was mainly explained by the SOC:clay ratio, regardless of tillage practices. Below a SOC:clay ratio of 0.08, all pools were decreasing nearly equally with decreasing SOC. Above this ratio, thermo-stable pools increased only slightly, while thermo-labile pools increased linearly with SOC:clay on the full SOC:clay range. The 0.08 SOC:clay threshold in the thermo-stable pools content corresponded to the lower threshold of structure stability determined for Swiss and UK soils, below which, on average, severely degraded structures are observed in the field. These findings suggest that a large proportion of thermo-labile pool is necessary for acceptable to high soil structure quality, to protect the thermo-stable forms from degradation, and to reach the carbon sequestration potential of the soil.

Soil aggregate stability governs field greenhouse gas fluxes in agricultural soils

Agriculture is responsible for 30–50% of the yearly CO2, CH4, and N2O emissions. Soils have an important role in the production and consumption of these greenhouse gases (GHGs), with soil aggregates and the inhabiting microbes proposed to function as biogeochemical reactors, processing these gases. Here we studied, for the first time, the relationship between GHG fluxes and aggregate stability as determined via laser diffraction analysis (LDA) of agricultural soils, as well as the effect of sustainable agricultural management strategies thereon. Using the static chamber method, all soils were found to be sinks for CH4 and sources for CO2 and N2O. The application of organic amendments did not have a conclusive effect on soil GHG fluxes, but tilled soils emitted more CO2. LDA was a useful and improved method for assessing soil aggregate stability, as it allows for the determination of multiple classes of aggregates and their structural composition, thereby overcoming limitations of traditional wet sieving. Organic matter content was the main steering factor of aggregate stability. The presence of persistent stable aggregates and the disintegration coefficient of stable aggregates were improved in organic-amended and no-tilled soils. Predictive modelling showed that, especially in these soils, aggregate stability was a governing factor of GHG fluxes. Higher soil CH4 uptake rates were associated with higher aggregate stability, while CO2 and N2O emissions increased with higher aggregate stability. Altogether, it was shown that sustainable agricultural management strategies can be used to steer the soil's aggregate stability and, both consequently and outright, the soil GHG fluxes, thereby creating a potential to contribute to the mitigation of agricultural GHG emissions.

高速耕作条件下土壤离散元参数标定

For the problem of lacking reliable values of soil parameters required for dynamic simulation analysis of soil under high-speed tillage, no-tillage soil was taken as the research object and its parameters were calibrated using the discrete element method in this study. The Edinburgh Elasto-Plastic Adhesion (EEPA) model was determined as the soil contact model by obtaining the loading force-deformation relationship through uniaxial sealing compression tests. The regression equation was established using Plackett-Burman test and quadratic orthogonal rotation test, and the interaction effects were analyzed. The measured values of the pile angle and strain were obtained through the pile angle test and the uniaxial seal compression test, and the optimal solution was carried out. Further, the simulated values and the measured values under the optimal parameters were compared and verified, the result showed that the error values were all less than 1%. Finally, the soil model was used for high-speed tillage simulation analysis, and the obtained soil particle displacement and groove width were compared with the measured values. It was found that the ditch width error value was 3.04% and the soil displacement was basically the same. This study proved that the contact model parameters were relatively reliable, which could provide theoretical reference for the dynamic characteristics of soil during high-speed cultivation of no-tillage soil.

Tillage reversal of long-term no-till soil increases crop yield while mitigating yield-scaled growing season GHG fluxes in a black Chernozem cropped to barley (Hordeum vulgare L.)

Tillage reversal of long-term no-till soil increases crop yield while mitigating yield-scaled growing season GHG fluxes in a black Chernozem cropped to barley (Hordeum vulgare L.)

Earthworms increase soil greenhouse gas emissions reduction potential in a long-term no-till Mollisol

Earthworm activity and plant residues in the soil can strongly influence soil organic carbon (SOC) dynamics. However, studies on how earthworms, especially epigeic and endogeic species alone or together, affect the main soil greenhouse gas (GHG) emissions (CO2 and N2O) and SOC under the long-term no-till (NT) and conventional tillage (CT) in Mollisols in Northeast China are unclear. The effects of two different species of earthworms (epigeic, Eisenia nordenskioldi; endogeic, Metaphire tschiliensis) on the soil GHG emissions and the SOC content were studied in NT and CT soils in a 337-day mesocosm experiment. The presence of earthworms enhanced the soil cumulative CO2 and N2O emissions in both NT and CT soils, and the soil GHG emissions (expressed in terms of the global warming potential, GWP) were increased by 20.43 %–42.99 % in NT soil and by 0–55.62 % in CT soil, respectively. Compared to E. nordenskioldi, the presence of M. tschiliensis (endogeic species) significantly increased soil GHG emissions. Earthworms in NT soil induced less soil GHG emissions than those in CT soil. The presence of earthworms did not increase the SOC content in CT soil but significantly increased the SOC content in NT soil. Our study suggests that earthworms in the long-term no-till soil can contribute to the reduction of soil GHG emissions. This research helps to understand the effects of different ecological categories of earthworms on soil GHG emissions and SOC dynamics under different tillage systems and to mitigate soil GHG emissions.

Water-stable aggregation among untilled and intensively tilled soils with similar contents of aggregating agents in central Ohio, USA

Organic carbon (OC), permanganate-oxidizable carbon (POXC), and autoclaved citrate-extractable (ACE) proteins are utilized as soil quality indicators due in part to their positive relationships with water-stable aggregation (WSA). Tillage-induced losses of WSA are oftentimes attributed to decreases in these soil constituents. The objective of the present study was to explain differences in WSA existing between tilled and untilled cropland soils through comparing the soils in terms of these and other aggregating agents. We examined WSA and a suite of related properties on conventional tillage (CT) and no-tillage (NT) soils of an Epiaqualf-Argiaquoll association along a low-relief hillslope in central Ohio, USA. Overall, WSA was strongly correlated (r > 0.7, P < 0.05) with OC, POXC, and ACE proteins, but when concentrations were similar between NT and CT soils for these constituents, most notably at the toeslope position, WSA was consistently greater for the NT soil. Statistically controlling for the effect of these individual WSA covariates did not change this result. Results suggest that heightened WSA for the NT vs. the CT soil may be due to the greater water repellency of the former when other aggregating agents are equivalent between tillage regimes. These findings suggest that soil quality evaluators should measure WSA directly rather than rely on inferences based on organic constituents, especially when working with CT soils from poorly drained, depositional landscape positions.

CURRENT TRENDS IN THE DEVELOPMENT OF AGRICULTURAL SYSTEMS IN THE UDMURT REPUBLIC

Minimisation of soil tillage is one of the defining trends in the development of agriculture. It allows for a significant reduction in agrotechnical operations in crop cultivation, thereby reducing the technological load on soils, energy, and labour inputs in production and increasing soil resistance to erosion processes. Minimum tillage effectively promotes the restoration of potential and adequate soil fertility and aligns with the principles of adaptive landscape agriculture. Despite numerous positive aspects of minimum tillage, its implementation in production is restrained by certain drawbacks: worsening of crop phytosanitary conditions, increased plough layer density, differentiation of the plough layer by agrochemical and agrophysical indicators, and more. To assess the possibility of implementing minimum tillage in the soil and climatic conditions of the Udmurt Republic, long-term field experiments have been conducted at the Udmurt Research Institute of Agriculture since 1980. Both positive and negative aspects of three types of primary soil tillage have been identified. Moldboard ploughing, throughout the observation period, compared to other types of tillage, provided the highest crop yield (by 0.15 0.50 t per hectare or 5.6 17.5%) and energy efficiency coefficient (by 1.9 16.7%). No-till soil treatment proved to be the most environmentally friendly, increasing the organic matter content in the 0-10 cm layer by 8.1 11.5%. However, it led to a strong differentiation of the plough layer into two sub-layers: 0-10 and 10-20 cm. The lower sub-layer was characterised by higher density and lower content of mineral nutrients and humus. In most cases, combined tillage showed intermediate results. Further scientific research is needed to develop agrotechnologies with more significant minimisation of soil tillage.

Soil Sampling Depth in No-Till Acid Soils

ABSTRACT Ammonia-based fertilizers acidify the soil during the nitrification process. No-till and other reduced till system soils are more susceptible to stratified acidification than conventionally tilled soils as there is little soil mixing. Many long-term no-till soils have acidified in North Dakota, but there is little guidance on soil sampling depth. This project evaluated what soil depth/s should be collected to remediate acid soils. Twelve differing acidic soil types across North Dakota were sampled at the 0–5.1, 5.1–10.2, 10.2–15.2, 0–7.6, 7.6–15.2, and 0–15.2 cm depths and analyzed for pH. The comparison of means procedure determined that the 0–7.6 cm soil pH was the most acidic (p-value < .001). The 0–5.1, 0–15.2, and 5.1–10.2 cm depths were similar. The highest soil pH was observed at the 7.6–15.2 and 10.2–15.2 cm depth. Soil acidity management of no-till soils when acidification is caused by nitrification should be sampled at the 0–7.6 cm depth as that pH was the most acidic and encompasses the soil environment that surrounds relatively shallow and deeply sown North Dakota crops.

Field-scale heterogeneity overrides management impacts following conversion to no-till within an arable system

Crop establishment in no-till arable systems benefits from soil health conducive for growth. Combined with the incorporation of crop residues and manures, no-till can influence soil organic carbon (SOC) and organic matter (SOM) dynamics, crop productivity and nutrient cycling. These processes are shaped by spatial and temporal factors including associated microbial activity. This study aimed to investigate the interaction between microbial and soil physicochemical properties during the transition from full-inversion to no-till soil management. Assessments were conducted over a two-year period and included a combination of soil microbial assays (microbial biomass carbon and nitrogen with physicochemical analyses, SOC, SOM, textural class, pH, gravimetric water content, and macronutrients). Two experiments were established within the same four-hectare field: one on a relatively level area (Experiment-1) and another on a slope (Experiment-2). Experiment-1 treatments consisted of Farmyard Manure (FYM and N-fertiliser), Green Manure (GM, Raphanus sativus and Vicia sp. mix) and Standard Practice (SP = Control, N-fertiliser only). Experiment-2 was a repeat of Experiment-1, but without the FYM treatment. Soil was sampled twice per crop season, in Spring and Autumn, in Experiment-1, and in Autumn only in Experiment-2. The results were influenced by spatial (i.e. where the same was collected from) and temporal (i.e. the time at which the same was collected) variations that were not always linked to management practices. This study demonstrated that the quantification of SOC and SOM were poor predictors of change in management practices over two years, while microbial biomass responded quickly to the incorporation of FYM. SOC and SOM were affected by soil texture, but not significantly by inputs, and were associated with extractable Ca2+ and total-N. Diachronic studies increase our understanding of biological and physicochemical dynamics in response to short-term change in soil management practices. This study emphasises the impact of soil texture within a single heterogenous field, and how it affects management outcomes. It highlights the importance of considering spatial differences to develop effective and sustainable agricultural solutions.

Lime and gypsum application to low-acidity soils: Changes in soil chemical properties, residual lime content and crop agronomic performance

Crop yield gains and improvements in surface and subsurface soil chemical properties are evident when agricultural lime and gypsum are used in high-acidity soils. However, there is scarce information on the effects of lime and gypsum application on no-till tropical soils previously treated with these additives (low-acidity soils). The duration of the effects of lime applied to the soil surface varies according to lime rate, product characteristics, soil conditions, and water and thermal regimes. Such residual effects influence the timing of lime reapplication. This study aimed to investigate the effects of surface application of agricultural lime and gypsum on soil chemical properties, soybean and second-crop corn yields, and lime residual contents. The experiment was conducted on a Red Latosol with a very clayey texture in Floresta, Paraná, Brazil. Four rates of dolomitic lime (0.0, 2.6, 5.4, and 8.1 Mg ha−1) and agricultural gypsum (0, 4, 8, and 12 Mg ha−1) were used. The experimental design was a randomized complete block with subplots and four replications. The experiment lasted for four soybean seasons and three second-crop corn seasons. At 6, 12, 24, and 36 months after treatment, soil samples were collected from the 0.00–0.05, 0.05–0.10, 0.10–0.20, 0.20–0.30, 0.30–0.40, and 0.40–0.60 m layers for chemical analysis. No significant interaction effects were observed on soil chemical properties. Liming resulted in soil alkalization, with a consequent reduction in Al3+ and an increase in Ca, Mg, base saturation, and pH. Residual lime was not detected in layers deeper than 0.05 m, suggesting a lack of physical movement of particles in the soil pore space. Residual lime was detected on surface soil (0.00–0.05 m) up to 36 months after application, demonstrating the low reactivity of lime on no-till soils. At 6 months after gypsum application, there was an increase in Ca2+ levels up to the 0.6 m layer, whereas Mg2+ levels were reduced throughout the soil profile for up to 36 months. In no-till soybean–second-crop corn rotation systems, use of agricultural gypsum alone did not provide consistent effects on crop yield and reduced foliar Mg contents. Under the studied conditions of low acidity, liming did not produce significant differences in crop yield but improved soil chemical properties for plant growth under no-till.

Does no-tillage mitigate the negative effects of harvest compaction on soil pore characteristics in Northeast China?

Optimizing tillage management is one way to reduce the risk of soil compaction due to traffic load in Northeast China. In this study, we aimed to examine the responses of precompression stress (σpc), compression index (Cc), pore morphology (>30 µm), air-filled porosity (εa60), air permeability at matric potential of − 60 hPa (ka60) and saturated hydraulic conductivity (Ks) to harvest traffic on soil from two contrasting tillage practices using a 10-yr old field experiment. After the crop was harvested with a combine harvester, undistributed soil cores were collected in the 0–10 and 10–20 cm layers from non-traffic and traffic zones of no-tillage (NT) and moldboard plough (MP) plots. In the non-traffic zone, the MP management showed greater total porosity (εtotal), εa60 and macroporosity (εX-ray) than the NT. There were no differences in pore connectivity, mean pore size and ka60 of the 0–10 cm layer and in Ks of the 0–20 cm layer between the two tillage practices, however, more biopores were observed under NT. Harvest traffic showed no significant effects on NT soil. In the MP plots, the εtotal, εX-ray, and pore connectivity, were decreased and pores larger than 0.15 mm were preferentially compacted. As a result of traffic, MP soil displayed lower ka60 in the 0–20 cm layer and lower εX-ray and connectivity in the 10–20 cm layer. In the NT management, the pore system had greater water and air conduction efficiencies and stable properties. Thus, compared to MP, NT can mitigate the negative effects of harvest compaction on soil in Northeast China.