The study, conducted by soil scientists Michael Akaninyene Okon and Angelica Ngozichukwu Udi of the Federal University of Technology Owerri and published in BMC Agriculture, focused on three communities — Isingwa, Ngwaukwu and Ntigha — where cassava cultivation dominates the landscape. The team collected fifteen surface soil samples from a depth of 0 to 20 centimetres in March 2023, timed deliberately at the onset of the rainy season, using a free survey approach across randomly chosen points. Each location was geo-referenced with a handheld GPS, and field observations of colour, structure, drainage, stoniness and topsoil depth were paired with laboratory measurements of bulk density, porosity, hydraulic conductivity, water retention and aggregate stability.

The setting matters. Isialangwa North lies in the humid tropics, where annual rainfall of roughly 2,500 to 3,000 millimetres arrives in intense bursts peaking in July and September, and temperatures range from 27 to 35 degrees Celsius. The soils there formed from coastal plain sand of the Benin formation, a parent material that gives the region its characteristically sandy texture. Farming is the principal economic activity, sustained by bush fallowing supplemented with inorganic fertiliser, and practised almost entirely as rain-fed agriculture on ridges and mounds. In such an environment, the physical fabric of the soil — how it stores and transmits water, how it withstands the pounding of tropical storms — largely determines whether a farm thrives or slides toward erosion.

To translate raw measurements into a health verdict, the researchers adopted a rating scheme aligned with the Food and Agriculture Organization’s list of physical soil health indicators, scoring each attribute from 0 to 3, where 0 denotes healthy, 1 sub-healthy, 2 weak and 3 degraded. The framework rests on a simple premise: a healthy soil should hold water well, drain freely, resist compaction, provide sufficient depth for roots and maintain a stable structure. Any significant deterioration in these properties pushes the soil down the scale, with consequences that cascade into nutrient cycling, root development and ultimately crop yield.

On several counts, the news was genuinely encouraging. Bulk density, a measure of how tightly soil particles are packed, ranged from 1.18 to 1.29 megagrams per cubic metre across the three sites — values low enough to indicate the soils are not compacted and will not physically restrict root growth. Total porosity, calculated from bulk density and a standard particle density of 2.65, ranged from 51.09 to 55.62 percent, comfortably in the healthy class. Saturated hydraulic conductivity, measured with the constant-head method, fell between 0.009 and 0.011 centimetres per second, within the range considered ideal for crop production in Nigeria. The soils were also well drained, essentially free of stones, and — in Isingwa and Ngwaukwu — possessed healthy topsoil depths, with only Ntigha slipping to sub-healthy on that measure.

But two indicators told a darker story. Aggregate stability, assessed through water-stable aggregates larger than 0.25 millimetres, ranged from a mere 6.96 to 8.79 percent, earning the soils a degraded rating of 3. In practical terms, when rain hits these soils, the clumps of particles that give soil its sponge-like architecture fall apart — a process known as slaking — leaving fine particles free to disperse, crust and wash away. The mean weight diameter of the aggregates, at roughly 0.012 millimetres for wet sieving, was far below the 0.4-millimetre threshold that marks even the ‘unstable’ category, placing the soils firmly in the very unstable class. Soils with such low values, the literature warns, erode far more readily than those with robust aggregation.

Water retention fared no better. Using Saxton’s hydraulic calculator, the team found the soils could hold only 7.3 to 8.1 percent water — squarely in the ‘low’ band of the standard rating, and thus degraded. Ntigha retained slightly more water than the other sites, a difference the researchers attribute to its higher clay content, but even that advantage was marginal. The culprit is almost certainly the region’s sandy texture combined with chronically low organic matter: sandy soils have few fine pores to capillary-bind water, and without organic matter to act as a sponge, rainfall simply percolates beyond the reach of roots. For rain-fed farmers, that means crops face water stress within days of every dry spell between storms.

The correlation analysis added a revealing layer to the story. Water-stable aggregates correlated positively with clay content, total porosity, organic carbon, total nitrogen, organic matter, microbial biomass carbon, calcium and total exchangeable bases — and negatively with bulk density. Bulk density, in turn, was strongly and negatively linked to organic carbon, nitrogen, organic matter and microbial biomass, and showed a perfect inverse relationship with total porosity. Water retention rose sharply with clay (a correlation of 0.910) and total exchangeable acidity, but fell with sand, silt, pH, organic carbon, nitrogen, calcium, magnesium and base saturation. The pattern is coherent: the same organic matter that feeds soil microbes also glues particles into stable aggregates, and anything that depletes it — continuous cultivation, erosion, removal of residues — simultaneously undermines structure, water storage and fertility.

Soil colour and structure filled in the picture. All three sites showed a fine granular structure, the most desirable arrangement for aeration and root penetration, but its grade was weak, with aggregates barely observable in the field — a rating of 2, or weak. Isingwa and Ngwaukwu soils were brown, a hue associated with humification and the decomposition of plant and animal remains, while Ntigha’s reddish tone pointed to abundant iron oxides inherited from the coastal plain sand parent material and intensified by the region’s climate. Colour, the researchers note, is a quick visual proxy for organic matter content and drainage conditions, and the brown-to-reddish palette here ranked as weak rather than the dark, humus-rich colours of a truly thriving soil.

Averaged across all ten physical indicators, each of the three communities scored 1 — sub-healthy — and the authors are clear about what should happen next. They recommend cover cropping, crop rotation, organic mulching and organic manuring to rebuild aggregation and water-holding capacity, alongside reduced or no-till approaches and integrated nutrient management to protect the structure that remains. They also call for follow-up studies that fold chemical and biological indicators into the assessment, since physical health alone cannot capture the full functional state of a soil. For a region where farming is the economic backbone and the rains arrive with erosive force, the message is urgent: the soils of Isialangwa North are not yet broken, but the glue that holds them together is thinning, and only deliberate conservation can keep them on the right side of the health scale.

Subject of Research: Physical soil health assessment of tropical agricultural soils in Isialangwa North, southeastern Nigeria

Article Title: Assessment of the physical health of tropical agricultural soils in Isialangwa North, Southeastern Nigeria

Article References: Okon, M. A., & Udi, A. N. (2025). Assessment of the physical health of tropical agricultural soils in Isialangwa North, Southeastern Nigeria. BMC Agriculture, 1(1), Article 13. https://doi.org/10.1186/s44399-025-00011-z

Image Credits: AI Generated

DOI: 10.1186/s44399-025-00011-z

Keywords: soil health, tropical soils, aggregate stability, water retention, bulk density, hydraulic conductivity, soil porosity, Nigeria, cassava farming, soil degradation, soil conservation, soil structure

The research team, led by Luiz Henrique Quecine Grande and Moacir Tuzzin de Moraes of the University of São Paulo’s Luiz de Queiroz College of Agriculture, set out to fill a persistent gap in crop modelling. Semi-empirical models that link root elongation to soil penetration resistance and water status exist for soybean, wheat and maize, but no equivalent framework had been built for sugarcane. That omission matters because sugarcane is a semi-perennial crop: its root system is renewed after each harvest and must keep functioning across ratoon cycles lasting three to ten years, exposing it to soil physical constraints far longer than annual crops face. If soil structure shapes how roots respond to stress, then any model that ignores structure risks systematically misjudging how deep and fast sugarcane roots will grow, and therefore how much water they can extract during drought.

To isolate the effect of structure, the team designed an elegant three-way comparison. Soil cores with undisturbed structure were collected from a field trial established in 1993, which compares conventional tillage, last disturbed five years before sampling, with a no-tillage system that had gone 31 years without mechanical disturbance apart from furrow opening at planting. A third treatment consisted of repacked soil, sieved and compressed into cylinders at five bulk densities, deliberately destroying any continuous pore network. The soil itself was a clay-rich Rhodic Eutrudox, an Oxisol with roughly 70 percent clay, typical of Brazil’s premier sugarcane region. Sampling at 0 to 20 centimetres captured the topsoil where most early root activity occurs, and 100 undisturbed cores per tillage system ensured the natural field variability in compaction was represented rather than averaged away.

Each structural condition was then subjected to a matrix of five levels of mechanical stress and five levels of hydric stress. The researchers equilibrated the cores at matric potentials ranging from a wet −5 hPa to a dry −8000 hPa, producing degrees of water saturation between roughly 58 and 95 percent. Pre-sprouted sugarcane seedlings, 60 days old, had their existing root systems carefully removed so that only new, uniform first-order roots of 0.5 to 2 centimetres were transplanted into the cores. After about 95 hours in a growth chamber held at 27 degrees Celsius, the roots were extracted, washed and measured. The elongation rate, expressed in centimetres per day, became the response variable for every combination of structure, compaction and moisture, with a maximum observed rate of 3.62 centimetres per day under stress-free control conditions.

The results revealed a striking hierarchy of vulnerability. In the repacked soil, root elongation collapsed by up to 84 percent as compaction increased, falling from 3.04 to just 0.51 centimetres per day under near-saturated conditions. Conventional tillage soil showed intermediate losses, declining from 2.14 to 0.69 centimetres per day across the same compaction range. The 31-year no-tillage soil, by contrast, lost only about 30 percent of its elongation rate across the entire compactness range from 75 to 95 percent. Under the harshest combination tested, a penetration resistance of about 6.2 megapascals at 95 percent water saturation, roots in no-tillage soil grew 8.2 times faster than in repacked soil and 1.8 times faster than in soil under conventional tillage. Mechanical impedance, the team concluded, was the dominant stress, with water stress acting largely by amplifying it.

The mechanism behind this resilience lies in the pore network. As macropore volume, the fraction of pores larger than 50 micrometres, declined from 0.20 to 0.05 cubic metres per cubic metre, root elongation fell by only 38.5 percent in the no-tillage soil, but by 74.4 percent under conventional tillage and 83.1 percent in repacked soil. Remarkably, roots in no-tillage soil at a macropore volume of 0.05 grew as fast as roots in the other treatments at roughly 0.12, meaning the preserved structure effectively compensated for a loss of more than half the macroporosity. Saturated hydraulic conductivity told the same story: at equivalent macropore volumes, water moved through the structured soils up to 3.3 times faster than through the repacked samples, indicating that the remaining pores in undisturbed soil were better connected and more permeable.

From these data the researchers fitted a three-dimensional Gaussian model expressing root elongation rate as a joint function of penetration resistance and degree of water saturation, one model per structural condition. The models performed well, explaining 47 percent of elongation variability in conventional tillage, 71 percent in no-tillage and 78 percent in repacked soil, with determination coefficients above 0.87 and near-zero bias. The shape of the response surfaces carried the key message: the same nominal physical stress produced very different elongation rates depending on structure. The authors argue this means root elongation functions cannot simply be transferred between soils with contrasting structural histories, a caution that applies directly to the agro-hydrological models, such as Canegro and SWAP, which often assume constant root growth rates regardless of what the soil is doing.

To translate the laboratory measurements into architectural consequences, the team integrated their stress functions into RootBox, a three-dimensional functional-structural root model. Simulating 45 days of growth at a moderate water saturation of 81 percent, they found rooting depth reached 31 centimetres in the no-tillage scenario, 20 centimetres under conventional tillage and only 15 centimetres in repacked soil, roughly half the no-tillage depth. Under completely stress-free conditions, simulated roots reached about 65 centimetres, underscoring how much potential depth is forfeited to physical limitation. Deeper rooting is not an aesthetic detail: it determines access to subsoil water during dry spells, and previous field studies have linked no-tillage to greater sugarcane root biomass at depths of 80 to 100 centimetres.

The findings carry practical weight for one of the world’s largest sugar and bioenergy crops. Conventional tillage temporarily loosens compacted layers, but that loosening is short-lived and can leave subsurface plough pans while degrading load-bearing capacity under heavy harvester traffic. The new results suggest that abandoning disturbance, or simply leaving tilled soil undisturbed for five years as in the conventional treatment here, allows a continuous, biologically generated pore network to re-establish, giving roots low-resistance pathways through otherwise hostile ground. These biopores, left behind by decayed roots, also improve gas diffusion, which matters because waterlogged, compacted soil can suffocate the oxygen-hungry meristem at the root tip. The study notes that roots sense compaction partly through restricted ethylene diffusion, a hormonal signal trapped by dense soil, and that preserved pore continuity appears to blunt this stress perception.

The authors are careful about limits. Their models are calibrated for penetration resistances between 1 and 8 megapascals and water saturations between 50 and 95 percent, so drier conditions and full saturation remain outside their predictive range, and the RootBox simulations were illustrative rather than field-validated. The penetration resistance equation, fitted with the Busscher model, is best suited to soils with similar clay content. Even so, the central conclusion stands firmly: soil structure is not a passive backdrop to root growth but an active buffer against mechanical and hydric stress, and it deserves a place inside the soil–plant–atmosphere models that forecast crop water use. For an industry facing more erratic rainfall and heavier machinery, the message from this Brazilian Oxisol is that the cheapest root growth insurance may simply be to stop disturbing the ground.

Subject of Research: The effect of no-tillage soil structure on sugarcane root elongation under mechanical and hydric stresses in a Brazilian Oxisol

Article Title: No-tillage soil structure increases sugarcane root elongation under mechanical and hydric stresses in an Oxisol

Article References: Grande, L. H. Q., Macedo, M. D., dos Santos, J. K., da Silva, L. H. A., de Alencar, A. A., dos Santos Vianna, M., Bolonhezi, D., & de Moraes, M. T. (2026). No-tillage soil structure increases sugarcane root elongation under mechanical and hydric stresses in an Oxisol. Plant and Soil. https://doi.org/10.1007/s11104-026-09113-2

Image Credits: AI Generated

DOI: 10.1007/s11104-026-09113-2

Keywords: sugarcane, no-tillage, soil structure, root elongation, soil compaction, penetration resistance, biopores, macroporosity, Oxisol, soil physics, root growth modelling, hydric stress

The team’s starting point was a gap in the literature. The link between soil aggregates and soil organic carbon cycling has been documented extensively, yet the combined effects of irrigation regime and exogenous organic carbon additions on aggregate distribution, aggregate-bound carbon and microbial communities in paddy soils remained poorly understood. Paddy soils are an unusual case: they spend much of the growing season saturated, which changes everything from oxygen availability to how particles stick together. As water-saving irrigation schemes spread across rice-growing regions to conserve scarce freshwater, researchers have worried about what drier, more fluctuating moisture conditions do to the physical structures that protect carbon in these soils. The new experiment was designed to answer that question directly.

Methodologically, the study was deliberately gentle with its samples. Rather than subjecting soil to aggressive dry sieving, which can shatter natural aggregates and distort the size distribution, the researchers used an optimal-moisture sieving method, working the soil at a moisture content chosen to preserve aggregate integrity. Soil was separated into size classes, from large aggregates larger than 2 millimeters down to fine fractions smaller than 0.25 millimeters. The treatments compared flooding irrigation with controlled irrigation, and each water regime was crossed with additions of rice straw or with hydrochar produced from that same straw by hydrothermal carbonization — a process that converts wet biomass into a carbon-rich, chemically altered solid using heat and pressure in water.

The first striking result is how lopsided paddy soil architecture turned out to be. Across the treatments, aggregates larger than 2 millimeters dominated the soil mass, accounting for between 67 and 80 percent of the total, while the finest fraction below 0.25 millimeters was the least abundant class at just 7 to 16 percent. That imbalance matters more than it might seem. When scientists calculate how much organic carbon sits in the soil as a whole, the bulk of the number comes from whatever size class holds most of the mass — in this case, the big aggregates — even if smaller fractions are individually richer in carbon per gram. The study confirmed exactly this pattern: the fine fractions were enriched in organic carbon and microbial attributes, yet the larger-than-2-millimeter class made the largest numerical contribution to calculated bulk soil organic carbon simply because of its overwhelming mass proportion.

Water management left a clear fingerprint on this architecture. Compared with continuous flooding, controlled irrigation increased the proportion of large aggregates greater than 2 millimeters and improved aggregate-related structural indices, as reflected in higher values of mean weight diameter and geometric mean diameter — two standard measures that essentially summarize whether a soil is dominated by sturdy, well-formed crumbs or by loose, easily eroded fragments. For a water-saving technique, that is a reassuring outcome. It suggests that the drying and re-wetting cycles inherent to controlled irrigation do not necessarily degrade paddy soil structure; instead, under the conditions of this experiment, they appear to have nudged the soil toward a coarser, better-aggregated state.

Adding exogenous organic carbon raised the amount of organic carbon associated with aggregates in both water regimes, but the two amendments behaved in intriguingly different ways. Rice straw proved the stronger stimulator of microbial biomass, consistent with its role as a fresh, easily decomposable food source for soil organisms. Hydrochar, by contrast, produced a greater increase in the proportion of large aggregates and in the organic carbon concentration within that greater-than-2-millimeter class. In other words, straw fed the microbes, while hydrochar built the structure — and locked more carbon into the biggest, mass-dominant crumbs. The authors conclude that hydrochar amendment under controlled irrigation improved aggregate-related structural characteristics and increased aggregate-associated organic carbon mainly by boosting both the mass share and the carbon concentration of the large-aggregate fraction.

The interaction between the two levers was not simply additive. The study found that controlled irrigation and hydrochar amendment influenced aggregate distribution and aggregate-associated organic carbon independently and, for some aggregate-size responses, interactively. This nuance carries practical weight: it means farmers and researchers cannot assume that the effect of a soil amendment is the same under a flooded field as under a water-saving schedule. The moisture regime sets a context that shapes how organic additions translate into physical structure and carbon stabilization, which is precisely the kind of information needed to design management packages rather than isolated interventions.

Why should carbon cling to large aggregates so effectively when hydrochar enters the picture? The mechanistic story, as the authors and the surrounding literature frame it, involves the way particulate organic materials act as binding agents. Fresh plant residues serve as nuclei around which mineral particles and microbial products accumulate, forming larger and more stable aggregates. Hydrochar, being more chemically recalcitrant than raw straw, persists longer and may act as a durable skeletal component within these crumbs, while its own carbon rides along inside the aggregate structure. Meanwhile, the enrichment of organic carbon and microbial attributes in the fine fractions reflects the reality that microaggregates offer protected microhabitats where decomposers and their substrates are held in close, moisture-buffered contact. Both ends of the size spectrum do important work — they just do it in different currencies.

For rice systems, which cover vast areas of Asia and store substantial carbon in their periodically waterlogged soils, the findings arrive at a moment when water scarcity is pushing irrigation reform and carbon accounting is tightening around agriculture. Controlled irrigation is already valued for cutting water use and, according to related work by overlapping research groups, for mitigating methane emissions from paddies. This study adds a structural dimension to its credentials: the practice did not sacrifice, and in fact improved, the aggregation metrics that underpin soil physical health. Pairing it with hydrochar made from the very straw that rice harvests generate offers a circular route — crop residue is converted off-field and returned as a stable carbon amendment that reinforces soil structure rather than decomposing rapidly and releasing its carbon back to the air.

Cautions remain, as they always do with short-term experiments. The aggregates and microbial responses reported here were measured under experimental conditions, and longer-term field studies will be needed to confirm that hydrochar-driven gains in large-aggregate carbon persist across seasons and soil types, and that microbial stimulation by straw does not simply accelerate carbon loss elsewhere in the system. The researchers also note that datasets from the study are available from the corresponding author on reasonable request, inviting replication. Still, the central message is crisp and actionable: the amount of carbon a paddy soil can bank depends not just on what you add to it, but on how wet you keep it — and the best results come when the two are tuned together.

Subject of Research: Effects of controlled irrigation and hydrochar amendment on soil aggregate-size distribution and aggregate-associated organic carbon in paddy soils

Article Title: Controlled irrigation and hydrocchar amendment alter aggregate-size distribution and aggregate-associated organic carbon in paddy soils

Article References: Controlled irrigation and hydrocchar amendment alter aggregate-size distribution and aggregate-associated organic carbon in paddy soils. (n.d.). https://doi.org/10.1007/s11104-026-09144-9

Image Credits: AI Generated

DOI: 10.1007/s11104-026-09144-9

Keywords: paddy soil, soil aggregates, hydrochar, controlled irrigation, soil organic carbon, rice straw, microbial biomass, aggregate stability, carbon sequestration, water-saving irrigation, soil structure, hydrothermal carbonization

The stakes are considerable. Tillage is among the most energy-intensive operations in crop production, and improper machinery use during land preparation can irreversibly damage soil structure. Deep ploughing demands enormous power to fracture compacted horizons, which is why manufacturers have developed machines that pair a passive subsoiler shank with an active, powered rotary tiller. The rotary component pulverizes the soil the subsoiler cracks open, mixes in fertilizer, crop residues and organic amendments, and reduces the number of field passes needed. Fewer passes mean less compaction, less fuel, less labor and less time in the field. But until now, designers have lacked a reliable way to predict exactly what such combined implements do to the soil profile before the steel ever touches the ground.

DEM offers that window. The technique, pioneered in the geotechnical literature since the late 1970s, treats soil not as a continuous medium but as millions of individual particles, solving the equations of motion for each one as they collide, slide and cohere. In this study, the team modeled the soil bed in Altair EDEM 2022 software using the hysteretic spring with linear cohesion contact model, which adds a cohesion resistance to the normal contact forces between particles to mimic the behavior of real clay. The implement itself was designed in PTC Creo Parametric 3D modeling software and imported into the simulation environment, allowing the researchers to replicate the exact geometry of the subsoiler-cum-rotary tiller used in physical tests.

Calibration was the critical step. Because no universally accepted procedure exists for selecting the micromechanical parameters that govern particle interactions, the team anchored their model to laboratory measurements. They worked with clay soil from the experimental soil bin at Nanjing Agricultural University, containing 47.0 percent clay, 36.5 percent silt and 15.5 percent sand, with an average bulk density of 1.5 grams per cubic centimeter. Direct shear tests under unconsolidated undrained conditions yielded cohesion, internal friction angle and shear strength via the Mohr-Coulomb equation, while a digital penetrometer measured penetration resistance at ten locations. Using the angle of repose method and reverse parametrization, the researchers iteratively adjusted restitution and friction coefficients until the simulated soil formed a natural pile at 36.87 degrees, matching the physical material’s behavior.

The validation results are striking. Across eighteen soil bin experiments, the mean horizontal tillage resistance measured by sensors on the three-point linkage of a motorized trolley was 1,950.474 newtons, while vertical resistance averaged 295.92 newtons. The DEM model reproduced these values with a relative error of just 0.4 percent for horizontal resistance and 4.9 percent for vertical resistance. Horizontal resistance predictions achieved a coefficient of determination of 0.9997 with a normalized root mean square error of 0.04, while vertical resistance reached an R-squared of 0.9. An unpaired t-test found no statistically significant difference between simulated and measured values for either component, meaning the virtual experiment was statistically indistinguishable from the real one.

The model also predicted the shape of the furrow left behind. Soil profilometer measurements of the tilled profile matched the simulation with a relative error of 4.3 percent, an R-squared of 0.9936 and a normalized RMSE of 0.23. Both experiment and simulation produced U-shaped furrows with loose soil at the bottom, a profile considered favorable for seed coverage. The average top width of the soil profile was 0.405 meters in the soil bin versus 0.3875 meters in the simulation, and bottom widths were 0.26 and 0.25 meters respectively, a close correspondence that underscores the model’s fidelity.

Perhaps the most consequential finding concerns soil mixing. By coloring the simulated topsoil and subsoil particles differently, the researchers could watch, in effect, inside the soil as the machine passed through. The L-shaped rotary blades promoted predominantly horizontal and downward soil movement with limited upward throw, allowing topsoil particles to migrate toward deeper layers without wholesale inversion of the profile. Even at a tillage depth of 30 centimeters, the natural layering remained discernible, a critical advantage over conventional rotary systems that churn the profile indiscriminately. The mixing of the two layers increased with cutting depth, as expected given the larger soil volume involved, but the vertical-axis rotation design avoided dragging subsoil to the surface, preserving stratification that underpins fertility and moisture retention.

The study also mapped how operating parameters drive energy demand. Both horizontal and vertical resistance rose as tillage depth increased from 0.15 to 0.30 meters, because deeper operation cuts, disperses and moves a greater volume of soil. Resistance likewise grew when forward speed increased from 1.5 to 2.5 kilometers per hour, since faster-moving soil particles gain acceleration, raising normal loads on the tool and thus frictional resistance. The substantial gap between horizontal and vertical forces, roughly 1,800 to 2,060 newtons versus 264 to 323 newtons, shows that far more energy is spent dragging the implement forward than penetrating downward. Notably, the rotary tiller’s rotational motion generated a forward thrust component that offset part of the draft requirement, one reason combined active-passive implements outperform conventional systems in energy efficiency.

The practical implications reach from the design office to the farm field. For manufacturers, the validated model provides a virtual testing platform to optimize blade shape, operating depth and rotational speed across diverse soil conditions without costly physical prototyping. The evidence points toward vertical-axis rotary tillers equipped with L-shaped blades as the configuration of choice for deep tillage that respects soil architecture. For farmers, the combined implement approach promises reduced operational time and fuel consumption while maintaining soil quality, addressing economic and environmental goals simultaneously. As the authors conclude, DEM can serve as an accurate, consistent and fast method for predicting the final soil condition and the resistances required for tillage operations, and with proper blade selection, deep tillage and soil structure conservation need no longer be opposing goals.

Subject of Research: Discrete element simulation of rotary mixing effects on soil structure and tillage resistance for a combined subsoiler and rotary tiller

Article Title: Evaluation of rotary mixing effects on soil structure and tillage resistance using discrete element method

Article References: Makange, N. R., & Ji, C. (2026). Evaluation of rotary mixing effects on soil structure and tillage resistance using discrete element method. Discover Soil, 3(1), Article 148. https://doi.org/10.1007/s44378-026-00308-8

Image Credits: AI Generated

DOI: 10.1007/s44378-026-00308-8

Keywords: discrete element method, tillage resistance, rotary tiller, subsoiler, soil structure, soil bin experiments, EDEM simulation, blade geometry, deep tillage, soil profile, precision agriculture, soil-tool interaction