Agroforestry deliberately combines trees with crops and/or livestock. The review reports that these systems can act as buffers against runoff and soil erosion, potentially limiting sedimentation and pollution entering nearby water bodies. Diverse practices and vegetation structures may also reduce chemical discharge and nutrient leaching. These are potential water-quality benefits rather than a universal outcome, and the review emphasizes that systems must be suitably designed and managed to deliver them.

The analysis also identifies possible water-conservation gains. Synergistic interactions between appropriately chosen tree and crop species may improve water-use efficiency, reduce irrigation requirements and promote groundwater recharge under suitable environmental conditions. Together with their capacity to buffer runoff and erosion, these mechanisms position agroforestry as a land-management approach that could support both clean-water goals and more resilient agriculture. The strength and transferability of the effects, however, would depend on climate, soils, species, crop choices and management practices.

Poorly implemented agroforestry can produce trade-offs. Dense tree cover may increase competition for water and reduce crop or pasture yields, while unsuitable combinations of species can limit productivity. Where livestock are integrated, inadequate management may also create risks of water contamination. The central finding is therefore conditional: agroforestry has potential to advance water management, but planting trees alone does not guarantee better water outcomes or lower agricultural demands.

Reported following PRISMA 2020 guidance, the review synthesizes records identified through Scopus and Web of Science and evaluates agroforestry as a water-management strategy, including its contribution to SDG 6, conditions associated with trade-offs or failure, and barriers to adoption. The authors identify policy constraints, technical skill gaps and land-tenure concerns as obstacles to wider use. They also point to legislative backing, capacity training and financial incentives as measures that could help overcome these barriers, supporting further consideration of agroforestry in efforts to improve water management and agricultural resilience.

Subject of Research: Systematic review of agroforestry practices for water management and Sustainable Development Goal 6.

Article Title: A systematic review of agroforestry practices for achieving the clean water sustainable development goal

Article References: Rachana, P. M., Murthy M, S., Kumaran, K., & Parthiban, K. T. (2026). A systematic review of agroforestry practices for achieving the clean water sustainable development goal. Discover Sustainability. https://doi.org/10.1007/s43621-026-05008-5

Image Credits: AI Generated

DOI: 10.1007/s43621-026-05008-5

Keywords: agroforestry, clean water, SDG 6, water quality, soil erosion, runoff, nutrient leaching, irrigation efficiency, groundwater recharge, systematic review, systematic, review

China’s experience spans landscapes with very different erosion processes and restoration constraints, including the Loess Plateau, northern deserts and the Qinghai-Tibet Plateau. The review divides national efforts into three stages. During the “Exploration Stage” from the 1950s through the 1980s, conservation focused on terracing, sediment-trapping dams, grass planting and afforestation. In the “Integrated Management Stage” from the 1980s through the 2000s, efforts expanded to manage small watersheds while linking erosion control with farming, rural livelihoods and economic development. Since the 2000s, the “Ecological Restoration and Sustainable Development Stage” has emphasized ecological restoration and sustainability, supported by stronger legislation, nationwide projects and closer oversight of construction. The review portrays this progression not as the result of one successful technique, but as a gradual expansion in the scale, coordination and monitoring of conservation policy.

National soil-conservation projects have spread across China since 2005, while satellite observations and other data systems have increasingly been used to identify erosion and track project development. The review’s central lesson is that durable results depend on combining engineering measures, ecological restoration, legal frameworks and attention to local livelihoods. Corresponding author Xing Yang said China’s experience shows that soil conservation succeeds when these elements are addressed together because no single measure can address the different forms of erosion found across varied landscapes. The reported decreases in affected area and eroded-soil volume are national-scale observations associated with decades of intervention; the review does not isolate the effect of any individual policy or restoration method.

Timing remains a defining feature of the evidence. Yang noted that the strongest decline in erosion area occurred years before the largest reduction in erosion volume, indicating a delay between intervention and its full effect. Restoration in fragile environments can be technically demanding, and unresolved erosion is increasingly concentrated in arid, high-altitude and otherwise vulnerable areas. The review also identifies competition among governments, farmers, businesses and the public as a potential complication in implementation. It therefore emphasizes ongoing monitoring and policy adjustment alongside long-term funding, scientific assessment and public participation. The findings offer transferable principles for countries confronting land degradation, but the scale and duration of China’s program—and its decades of national coordination—limit direct comparisons with shorter interventions elsewhere. The central conclusion is that launching conservation projects may begin a recovery process, whereas meaningful reductions in erosion generally require sustained implementation, local adaptation and patience.

Subject of Research: Historical review of China’s soil-conservation policies, erosion trends and long-term restoration outcomes

Article Title: China’s 70-year soil conservation journey shows why environmental recovery takes time

Article References: China’s 70-year soil conservation journey shows why environmental recovery takes time. Original publication (Bibliographic details unavailable.)

Image Credits: AI Generated

DOI: Not provided

Keywords: soil conservation, soil erosion, China, land restoration, environmental monitoring, ecological recovery, policy coordination, climate adaptation, year, soil, conservation, journey

The highest long-term values were concentrated in northern Kerala, while the smallest erosion-potential domain covered much of southern and parts of central Kerala. Rainfall erosivity describes the capacity of rainfall to detach and transport soil, while erosivity density expresses that erosive potential relative to the amount of rainfall. The two measures help distinguish the effect of how much rain falls from the effect of how intensely it falls.

For the analysis, the researchers converted daily gridded rainfall observations into monthly totals for each year and applied the Arnoldus empirical approach, a monthly-rainfall method widely used for long-term regional assessments. They calculated annual erosivity density as annual rainfall erosivity divided by annual rainfall. Trend significance was evaluated with the modified Mann–Kendall test, which adjusts for serial correlation, and trend magnitude was estimated with Sen’s slope method.

Agglomerative hierarchical clustering with Ward’s linkage then grouped grid cells with similar 120-year mean rainfall erosivity and erosivity density. The analysis identified a pronounced north–south gradient. Northern Kerala contained the highest minimum, maximum and mean rainfall erosivity, as well as the highest erosivity-density values.

The largest values occurred in and around Kasaragod, Kannur, Wayanad, Kozhikode and parts of eastern Palakkad, with additional high-erosivity areas in parts of Thrissur, Ernakulam and Kottayam. Most of central and southern Kerala had low to moderate values. The mapped patterns broadly followed rainfall totals, but rainfall erosivity had a higher coefficient of variation than rainfall, indicating that the erosive potential of Kerala’s rainfall was more variable across space and time than precipitation amount alone.

Four statistically distinct erosivity domains emerged from the clustering. The largest, C1, contained 23 cells and represented comparatively low conditions, mainly across southern and parts of central Kerala. Its mean rainfall erosivity ranged from 1,291 to 7,044 MJ mm ha⁻¹ h⁻¹ y⁻¹, and its erosivity density ranged from 1.34 to 3.38 MJ ha⁻¹ h⁻¹.

The intermediate C2 domain comprised 17 cells across much of central Kerala, with rainfall erosivity from 8,375 to 12,685 MJ mm ha⁻¹ h⁻¹ y⁻¹ and erosivity density from 2.45 to 3.99 MJ ha⁻¹ h⁻¹. Eight northern cells formed the high-erosivity C3 domain, reaching 21,643 MJ mm ha⁻¹ h⁻¹ y⁻¹ for rainfall erosivity and 5.76 MJ ha⁻¹ h⁻¹ for erosivity density. Two northern cells formed C4, the extreme domain, with rainfall erosivity of 26,974 to 29,987 MJ mm ha⁻¹ h⁻¹ y⁻¹ and erosivity density of 6.54 to 7.38 MJ ha⁻¹ h⁻¹.

Long-term averages nevertheless concealed substantial temporal variability. The 1991–2000 decade showed the widest spread in rainfall erosivity, from 1,269 to 38,824 MJ mm ha⁻¹ h⁻¹ y⁻¹, and the widest spread in erosivity density, from 1.26 to 10.53 MJ ha⁻¹ h⁻¹. Those ranges did not coincide with the highest average values: the decade with the greatest mean rainfall erosivity was 1921–1930, at 12,224 MJ mm ha⁻¹ h⁻¹ y⁻¹, and the highest mean erosivity density was 3.74 MJ ha⁻¹ h⁻¹.

Inter-decadal comparisons showed alternating periods of increase and decrease rather than a smooth progression. Rainfall erosivity rose most strongly between the second and third decades, while pronounced decreases occurred in several later transitions, particularly between 1991–2000 and 2001–2010. Comparing the first and last decades likewise showed that declines predominated statewide.

Statewide linear analysis confirmed the general direction of change. Mean annual rainfall decreased at a rate of 3.53 mm per year, with an R² of 0.1119. Mean rainfall erosivity declined by 34.34 MJ mm ha⁻¹ h⁻¹ y⁻¹ per year, with an R² of 0.1302, while erosivity density fell by 0.0074 MJ ha⁻¹ h⁻¹ per year, with an R² of 0.0947.

Grid-level results were more varied. For rainfall erosivity, 39 of 50 cells showed decreasing trends, including 33 statistically significant declines; 10 showed increases, five of them significant, and one showed no trend. Sen’s slopes ranged from −171.72 to 38.79 MJ mm ha⁻¹ h⁻¹ y⁻¹ per year.

For erosivity density, 40 cells declined, including 34 significant decreases, nine increased, including four significant increases, and one showed no trend. The strongest declines occurred in northern districts, whereas increases were confined to a few eastern highland locations. Elevation did not explain the regional pattern by itself.

In an analysis using 300 spatially distributed points sampled from interpolated surfaces, elevation had a moderate negative relationship with mean rainfall, with r = −0.49 and R² = 0.2418. Its relationships with rainfall erosivity and erosivity density were much weaker: r = −0.24 and R² = 0.0589 for erosivity, and r = −0.18 and R² = 0.0325 for erosivity density. Low-elevation locations generally received more than 3,000 mm of annual rainfall and often had greater erosivity, whereas high-elevation sites commonly received 1,000–1,500 mm, but considerable variation occurred within every elevation band.

The results indicate that monsoon circulation, rainfall intensity, seasonal distribution, topographic position and local atmospheric conditions jointly shaped erosivity rather than altitude acting as a simple control. The coexistence of declining long-term averages and episodic high-erosivity periods is an important feature of the record. A reduction in mean rainfall erosivity does not necessarily imply a proportional reduction in erosion hazard, because average conditions and extreme events represent different parts of the rainfall regime.

The monthly-rainfall method also cannot resolve the kinetic energy, duration or within-storm intensity of individual short-duration storms. Although this approach provides a consistent century-scale comparison, it may under- or overestimate local annual erosivity where extreme storms make a disproportionate contribution. The estimates describe climatic potential for soil detachment, not observed soil loss, which also depends on soil properties, vegetation, land use, slope, infiltration and sediment connectivity.

Likewise, the annual erosivity-density calculation describes long-term rainfall aggressiveness per unit rainfall rather than seasonal concentration or event-scale behavior. The spatial divergence also carries implications for erosion modelling. Because Kerala’s rainfall erosivity varies sharply over a comparatively small and topographically diverse area, applying one statewide R-factor could obscure localized high-erosivity conditions.

The four-domain classification provides an alternative framework for parameterizing Revised Universal Soil Loss Equation models, prioritizing watersheds and supporting spatially differentiated conservation planning. It does not by itself establish current erosion rates, however, and the four-cluster solution was selected through dendrogram interpretation rather than quantitative validation with indices such as silhouette width. High-temporal-resolution rainfall observations, climate projections and further analysis of extreme events will be needed to clarify future erosion susceptibility, but the current evidence shows that Kerala’s erosive rainfall has been highly variable despite its broad long-term decline.

Subject of Research: Century-scale analysis of rainfall erosivity and erosivity density across Kerala, India

Article Title: Century-scale spatiotemporal variability and trends of rainfall erosivity and erosivity density in an ecologically sensitive tropical monsoon region of India (1901–2020)

Article References: Valappil, N. K. M., Yusup, Y., Dewi, J. R., Huda, N., & Hamza, V. (2026). Century-scale spatiotemporal variability and trends of rainfall erosivity and erosivity density in an ecologically sensitive tropical monsoon region of India (1901–2020). Environmental Earth Sciences, 85(17), Article 437. https://doi.org/10.1007/s12665-026-13119-5

Image Credits: AI Generated

DOI: 10.1007/s12665-026-13119-5

Keywords: rainfall erosivity, erosivity density, Kerala, monsoon rainfall, soil erosion, Western Ghats, climate variability, Mann–Kendall test, hydroclimatology, RUSLE, spatial analysis, long-term trends

Researchers compared zero tillage, mulch tillage, reduced tillage, strip tillage and conventional tillage on clay loam soil. The study assessed sorghum grain yield and rainwater use efficiency alongside soil physical, chemical and hydrological properties, including soil organic carbon, total nitrogen, moisture retention, surface runoff and sediment loss. Its scope was the experimental field in the semi-arid environment of northern Ethiopia, so the findings concern the tested crop, soils and management systems rather than establishing the same ranking across all agricultural settings.

Strip tillage was the leading treatment in the reported comparison. Its mean grain yield of 3,771 kilograms per hectare exceeded the yields recorded under the other four systems, and it registered the best rainwater use efficiency. These were direct observations from the field experiment, not model projections or forecasts.

Together, the measures suggest that the strip-tillage treatment retained more effective use of rainfall while maintaining the experiment’s highest mean crop output, addressing two central constraints identified for farming in the region: water scarcity and soil degradation. The other systems showed distinct strengths and weaknesses. Mulch tillage was most effective at increasing soil organic carbon and total nitrogen and at retaining soil moisture, making it the strongest treatment for those particular indicators.

Zero tillage reduced sediment loss but generated the highest surface runoff, and that combination hindered crop performance. The comparison therefore did not show that minimizing soil disturbance was uniformly advantageous: under the experimental conditions, zero tillage limited sediment movement but did not minimize every pathway of water loss. Conventional tillage performed least well on the linked conservation measures.

It recorded both the highest runoff and the greatest sediment loss, with sediment reaching 28.2 tonnes per hectare. Overall, the findings identify strip tillage as the best measured compromise among the five options and mulch tillage as the leader for soil organic carbon, total nitrogen and moisture retention. They support targeted tillage management as a potential route to greater smallholder agricultural resilience in Tigray, while remaining specific to the conditions and indicators evaluated in the field trial.

Subject of Research: Field comparison of five tillage systems for sorghum yield, soil properties and water conservation in northern Ethiopia.

Article Title: Different tillage systems impact crop productivity and soil conservation parameters in the northern Ethiopian highlands

Article References: Kebede, M., Brhane, N., Haile, G. G., & Hagazi, N. (2026). Different tillage systems impact crop productivity and soil conservation parameters in the northern Ethiopian highlands. Discover Sustainability. https://doi.org/10.1007/s43621-026-04804-3

Image Credits: AI Generated

DOI: 10.1007/s43621-026-04804-3

Keywords: strip tillage, sorghum yield, rainwater use efficiency, soil conservation, soil erosion, surface runoff, mulch tillage, zero tillage, Ethiopian highlands, Tigray, Different, tillage

The study, published in Frontiers in Soil Science, compared Joniškis in northern Lithuania with Molėtai in the east. Joniškis is a 1,151.6-square-kilometre lowland district with a mean slope of about 1 degree, fertile loamy soils and extensive mechanized production. Arable land covered 71.9% of the district, and within the agricultural areas represented in the crop-declaration data, arable land accounted for 96.1%. Molėtai, by contrast, is a 1,366.8-square-kilometre moraine upland with a mean slope of about 3.3 degrees. Forests covered 38.6% of it, arable land 33.5%, and grasslands 9.6%. Among its declared agricultural areas, perennial grasslands and pastures were the largest category at 51.4%, compared with 26.4% arable land.

The differing terrain produced markedly different spatial structures. The Nature Frame occupied 610.9 square kilometres, or 53.0%, of Joniškis and 785.3 square kilometres, or 57.5%, of Molėtai. In Joniškis, geoecological divides represented 37.5% of the framework, migration corridors 37.6% and internal stabilization areas 24.8%, producing a comparatively balanced arrangement associated with broad watersheds and developed river valleys. In Molėtai, geoecological divides dominated at 63.0%, compared with 23.3% for migration corridors and 13.7% for internal stabilization areas. The hillier landscape contained extensive watershed and ridge systems dissected by valleys, lake basins and other hydrologically active forms.

Spatial overlay showed that 348.0 square kilometres of declared agricultural land in Joniškis fell within the Nature Frame, equivalent to 44.3% of the district’s declared agricultural area. Almost half of the arable land inside the framework lay in migration corridors, while 31.0% lay in geoecological divides and 20.8% in internal stabilization areas. This distribution raised a potential mismatch: the lowland setting favours intensive cultivation, but its corridors and divides also participate in the movement, accumulation and stabilization of water, sediment, nutrients and organic matter. The study did not directly measure degradation caused by this arrangement, but it identified where land-use intensity and geoecological role could be in tension.

Molėtai’s declared agricultural land within the framework covered 180.3 square kilometres, or 41.7% of its declared agricultural area. Its land-use pattern was substantially more diversified. Perennial grasslands and pastures occupied 97.8 square kilometres, natural grasslands 21.8, arable land 40.2, landscape elements 10.5 and temporary grasslands 10.0. The first three perennial and natural categories were concentrated in geoecological divides, where they accounted for 54.8%, 53.9% and 76.2%, respectively. Arable land was distributed among divides, corridors and stabilization areas at 35.9%, 40.3% and 23.8%. The contrast indicates that environmental heterogeneity in the upland district had already shaped a land-use structure more closely differentiated by landscape position than that of Joniškis.

To interpret the patterns, the authors developed a conceptual matrix linking agricultural categories with four soil-related criteria: tillage intensity, erosion potential, soil organic carbon accumulation potential and biodiversity conservation. The criteria were scored on the same ordinal scale and added without differential weighting. For arable land, scores for each criterion could be −1 or 1, producing a possible total from −4 to 4. Natural grasslands and landscape elements received the highest overall compatibility scores, followed by perennial grasslands, while temporary grasslands were intermediate and arable land received the lowest score. The assessment was expert-based and conceptual: the resulting map expressed the matrix spatially rather than independently validating soil-function compatibility.

The conceptual results nevertheless point to distinct management roles for the three types of Nature Frame zone. Geoecological divides, commonly positioned on elevated terrain where runoff is generated, were assigned priorities of reducing erosion risk, increasing soil organic carbon accumulation and maintaining soil stability. Migration corridors, including valleys and drainage systems that transmit water, sediments, nutrients and organisms, were linked to water regulation, reduced nutrient leaching, ecological connectivity and biodiversity. Internal stabilization areas were presented as potentially better suited to balanced agriculture that preserves soil fertility, landscape structure and long-term agroecosystem stability. Agricultural land outside the framework was not excluded from farming, but the model suggested that conventional management might be more compatible there while retaining general soil-conservation principles.

The authors say this is a decision-support concept rather than a territorial plan or a mandatory set of measures. Its central proposition is that management intensity should correspond not only to productivity conditions but also to a location’s role in the wider landscape. In intensively farmed, relatively homogeneous lowlands, the framework may reveal mismatches that are hidden by district-wide land-use statistics and provide a basis for targeted differentiation. The authors further propose that its value may be greater where agricultural intensification has simplified natural heterogeneity, while already diversified upland landscapes may require less additional spatial differentiation. That proposition remains a hypothesis requiring validation in other agricultural settings.

Several limitations constrain the findings. The study did not quantify erosion rates, soil organic carbon stocks or nutrient fluxes, and it did not test whether a particular field practice improved a measured soil function. Its conclusions depend on generalized expert scores and on the scale and resolution of the soil, cadastral, crop-declaration and landscape datasets, which can smooth local variation. The analysis was also limited to two Lithuanian districts and therefore cannot establish that the same pattern or management response will occur elsewhere. Future work would need direct soil measurements, quantitative spatial analysis, process-based modelling, remote sensing and testing in additional geomorphological settings, as well as more reproducible methods for delineating Nature Frame territories.

Within those bounds, the study offers a way to connect soil management with the larger organization of agricultural landscapes. Its contribution is not a finding that one crop or land-use category always protects the soil, nor a demonstration of improved yields or environmental outcomes. It is a spatial framework for asking where agricultural intensity may conflict with the functions assigned to a landscape position and where those functions may already be supported. The clearest mismatch occurred in Joniškis, where arable land frequently occupied migration corridors and other sensitive zones in an otherwise favourable landscape for intensive farming. Further field validation will determine whether applying the framework can translate that mapped mismatch into measurable gains in soil conservation, carbon retention, water regulation and landscape resilience.

Subject of Research: A conceptual GIS framework for aligning agricultural intensity with soil functions across contrasting Lithuanian landscapes.

Article Title: The Nature Frame as a landscape-based framework for integrating soil functions into agroecosystem management

Article References: Mačiulaitis, J., & Volungevičius, J. (2026). The Nature Frame as a landscape-based framework for integrating soil functions into agroecosystem management. Frontiers in Soil Science, 6, Article 1946432. https://doi.org/10.3389/fsoil.2026.1946432

Image Credits: AI Generated

DOI: 10.3389/fsoil.2026.1946432

Keywords: soil functions, agroecosystems, landscape ecology, Nature Frame, soil organic carbon, soil erosion, agricultural land use, spatial planning, land management, Lithuania, Nature, Frame

The results are model estimates for the catchment, rather than direct measurements of sediment exported from every slope. RUSLE estimates mean annual soil loss as the product of five factors: rainfall erosivity, soil erodibility, slope length, slope steepness, cover and management, and support practices. Rainfall erosivity, denoted R, was derived from 20 years of daily rainfall data in the NASA database and calculated with an empirical equation calibrated for East African highland conditions.

The resulting R values ranged from 527.507 to 888.624 megajoules per millimetre per hectare per hour per year, with the highest values in the eastern and southern catchment and lower values in central and northwestern areas. Station values were distributed across the landscape through inverse-distance weighting in ArcGIS, producing a continuous raster of rainfall erosivity. Soil erodibility, or K, was calculated from global FAO soil-texture and organic-carbon data.

It ranged from 0.239 to 0.688 tonnes per hectare-hour per hectare-megajoule per millimetre, with the highest values generally found in the south and northeast. These light-textured sandy and silty soils with relatively little organic matter were modeled as more susceptible to detachment and transport than clay-rich or organically enriched soils in the central and northwest. The K layer was constructed pixel by pixel with a raster calculator, while a 30-metre digital elevation model supplied the terrain information needed to estimate the combined slope-length and slope-steepness factor.

The study therefore combined regional climate records, global soil information and digital topography rather than relying on a single erosion gauge. The topographic factor, LS, ranged from zero to 1.678. It increased on long, steep slopes, where runoff has more opportunity to gather speed and transport detached particles, particularly in the northeastern and central catchment.

The cover-management factor, C, was derived from Landsat 8 near-infrared and red reflectance through the Normalized Difference Vegetation Index, or NDVI. Values ranged from 0.0004 in dense forest to 0.5237 in bare or degraded areas. This more than 1,300-fold range made vegetation cover one of the model’s most spatially variable controls.

The support-practice factor was fixed at 1.0 because the study found few formal soil-conservation structures in the catchment, so the mapped losses represent conditions without effective terracing, contour farming or comparable erosion-control practices. Multiplying the five raster layers produced the study’s estimated soil-loss range of zero to 51.4391 tonnes per hectare per year. The highest values occurred where the model combined high rainfall erosivity with high C and LS values, rather than in a single uniform zone.

In the northeastern Akanyaru Hills, annual cropland occupied steep, elongated slopes with locally more than 30-degree gradients. C values of roughly 0.25 to 0.52 represented limited protection during land preparation and early crop development, while R values reached the catchment’s upper range. The most degraded slope units in this zone had estimated losses approaching or exceeding 40 to 51.4 tonnes per hectare per year.

The model thus identifies the intersection of intense rainfall, topographic amplification and incomplete vegetation cover as a defining combination in the northeast. A second major hotspot lay in the southwest, where persistently bare and severely degraded land coincided with C values of approximately 0.45 to 0.524 and K values reaching 0.55 to 0.688. In model terms, this zone lacked even the partial canopy protection present in annual cropland, allowing rainfall and runoff to act directly on exposed mineral soil.

The southern forest margin formed a third vulnerable landscape: a shifting mosaic of remnant forest, newly cleared plots and pioneer grassland. Here, R values approached 888 megajoules per millimetre per hectare per hour per year, and clearing abruptly removed the very low C values associated with intact forest. These are spatial model patterns, not a measured time series of erosion before and after forest clearing.

Not every high-loss location depended on the same combination of conditions. Smallholder fields in the Gisagara and Nyaruguru southern uplands sat on moderately sloping terrain, with LS values around 0.5 to 1.0, but underlain by the catchment’s most erodible sandy and silty soils. The study attributed this pattern to depleted organic carbon and weak aggregate stability, showing why land cover alone cannot provide a complete erosion assessment.

In the Bugesera and Cyohoha transitional zone, modeled per-hectare losses were generally lower, often 5 to 20 tonnes per hectare per year, because slopes were gentler. However, drainage networks connected this mixed agricultural and expanding residential landscape to Cyohoha Lake, increasing the potential delivery of detached sediment to wetlands and a transboundary lake system. The distinction between erosion on a slope and sediment delivery downstream is important: the mapped estimate concerns soil loss across the landscape, while the lake connection identifies a pathway of potential transport rather than a measured sediment load.

The study recommends geographically targeted measures because its model identifies different dominant controls in different parts of the catchment. For steep agricultural slopes, it calls for bench terracing, grass and legume waterways and contour practices that interrupt runoff. Bare and degraded southwestern areas require rapid revegetation, including pioneer grasses, shrubs and agroforestry systems, while agricultural intervals with exposed soil could be protected with fast-establishing cover crops.

In the erodible southern uplands, the authors emphasize sustained organic-matter inputs, residue retention, reduced disturbance of soil structure and cross-slope contour bunds. Around Cyohoha Lake, riparian buffers, sediment-retention structures and controls on bare construction surfaces are proposed to reduce downstream sediment connectivity. These are conservation proposals based on the modeled vulnerability patterns; the research did not test their effectiveness in field experiments.

These findings should be read with the model’s limitations in mind. The analysis also relies on interpolated rainfall erosivity, global soil-texture information, satellite-derived vegetation cover and a constant support-practice factor; the accuracy of individual pixel estimates therefore depends on those inputs. The catchment’s different sub-catchments, including the Akanyaru Hills, Akanyaru Valley Left Bank and Akanyaru Cyohoha, also have different topographic and land-cover conditions, so the relative contribution of each factor varies across the landscape.

The 30-metre output provides a common spatial reference for identifying where modeled risk is concentrated, but it does not establish the amount of soil physically measured at a particular farm, nor does it demonstrate that land-cover change alone caused a measured increase in erosion. It offers a detailed baseline for comparing future conservation outcomes and targeting monitoring where steep slopes, exposed soil, erodible materials and intense rainfall overlap.

Subject of Research: Spatial modeling of soil loss across four land-cover types in Rwanda’s Akanyaru Catchment

Article Title: Quantification of soil loss by using RUSLE model under different land use and land cover conditions in AKANYARU catchment in Rwanda

Article References: Ntirenganya, J. B., Bugenimana, E. D., Niyonkuru, R., Iragena, A., Uwamahoro, P. C., Bosco, T. J., & Uwihirwe, J. (2026). Quantification of soil loss by using RUSLE model under different land use and land cover conditions in AKANYARU catchment in Rwanda. Discover Soil, 3(1), Article 191. https://doi.org/10.1007/s44378-026-00347-1

Image Credits: AI Generated

DOI: 10.1007/s44378-026-00347-1

Keywords: soil erosion, RUSLE, Akanyaru Catchment, land cover, rainfall erosivity, soil erodibility, agricultural slopes, GIS, Rwanda, erosion hotspots, Quantification, soil

The study, published in the open-access journal One Ecosystem, used the InVEST (Integrated Valuation of Ecosystem Services and Trade-offs) geospatial model suite to simulate two versions of the same 147-square-kilometre landscape. In the first scenario, the terrain was mapped exactly as official land-cover datasets record it — dominated by non-irrigated arable land and pastures, with hedgerows and similar features folded invisibly into those categories. In the second scenario, the researchers overlaid a high-quality federal dataset of officially mapped linear elements, which together cover roughly five per cent of the study region, so that hedgerows, wooded strips, isolated trees and field copses appeared as distinct habitat features in their own right.

The contrast between the two maps was striking for two of the four services tested. Mean pollinator abundance across the entire study region rose by 21.4 per cent once the linear elements were counted, and the share of land classified as having very high pollinator supply jumped from 20 per cent to 38 per cent. Nutrient export, the model’s measure of nitrogen and phosphorus losses from land to water, fell by 25 per cent on average — equivalent to a substantial rise in the landscape’s capacity to keep fertiliser runoff out of ground- and surface waters. By comparison, water flow regulation shifted only marginally, and erosion regulation barely responded at all.

What makes the pollination result particularly compelling is its spatial fingerprint. The benefit was not confined to the hedgerows themselves: pollinator abundance rose by 37 per cent within 50 metres of the linear elements and was still elevated by 27 per cent at 100 metres. Avoided nutrient export followed the same gradient, climbing 36 per cent next to the features and 30 per cent at 100 metres. In other words, a thin ribbon of semi-natural vegetation acts as a service-dispensing engine whose influence spills well out into the adjacent cropland — precisely the area where farmers need wild bees to visit their flowers and where nutrient losses are most damaging.

The mechanism behind the pollination effect is well understood from field ecology. Hedgerows supply nectar throughout the season, along with nesting sites and overwintering habitat for wild bees and other insects. Because the vegetation is permanent, unlike a crop that is harvested and tilled under, these structures act as stable reservoirs from which pollinators disperse into surrounding fields. Previous work has shown that hedgerows can function as net exporters of native bees into adjacent crops, and that landscapes rich in hedgerows enhance flower visitation and seed set regardless of the quality of local field margins. The new modelling results are consistent with that body of evidence, and with an earlier hierarchical assessment of pollination potential in the same study area.

The muted response of erosion and water flow regulation is more surprising, because hedgerows are famous for exactly those functions. Planted perpendicular to a slope, they shorten the effective slope length over which runoff water can accelerate, reduce wind speed and evaporation, and trap soil that would otherwise wash downhill. Field studies in northern Germany have even uncovered colluvial deposits built up behind historic hedgerow lines. The authors point to a likely explanation hidden in the geography: in the Bornhöved Lakes District, the steepest ground is largely under forest or grassland rather than cropland, and the linear elements are scarcest precisely in the hillier north where erosion risk is highest. A hedgerow can only interrupt runoff where there is runoff to interrupt.

There is also a technical caveat worth taking seriously. The InVEST models are transparent and widely used, but their outputs depend heavily on input data quality, resolution and minimum mapping unit. Narrow linear features are especially vulnerable: the official dataset records them as polylines, which had to be rasterised for the analysis, introducing some loss of precision. If a model cannot fully resolve a feature only metres wide, it risks underestimating the services that feature provides — which is, in a sense, the very bias the study set out to expose. The researchers mitigated this by comparing only relative changes between the two scenarios of the same landscape, classifying outputs into five quantile supply classes and removing statistical outliers before evaluation.

The policy implications reach directly into how the European Union builds its green infrastructure. EU strategy explicitly recognises that the network’s environmental features operate on very different scales, from small streams, ponds and hedgerows up to entire functional ecosystems. Yet in practice, national green infrastructure inventories — including Germany’s — typically exclude linear semi-natural elements on the grounds that they lack the critical mass and connectivity to contribute meaningfully. This study quantifies what that exclusion costs: five per cent of the landscape, properly accounted for, lifted pollination supply on agricultural land by 15.4 per cent and avoided nutrient export there by 22.9 per cent, with smaller gains in avoided quickflow.

For farmers, the arithmetic is unusually favourable. Planting or retaining a hedgerow occupies a sliver of land, yet the modelled returns — more pollinators visiting crops, less fertiliser bleeding into waterways, a more resilient soil base — accrue to the neighbouring fields that remain in production. The gains are largest within 50 metres of the feature, which gives land managers a concrete design rule: distribute linear elements so that no large block of cropland sits far from one. The regional biodiversity strategy of Schleswig-Holstein already praises structurally rich historic hedgerow landscapes; this study supplies the quantitative backing for treating those ribbons of wildness as infrastructure in the full, engineered sense of the word.

The authors are careful about the limits of a single model test. Four regulating services were assessed; cultural services, habitat provision and the condition of the elements themselves were not. Future work, they suggest, should layer in additional services, alternative models of higher hydrological complexity, and field data on the actual state of the hedgerows, since a degraded hedge supplies fewer services than a thriving one. But the central message survives every caveat: the thin green lines stitched through Europe’s farmland are not decoration. They are functional components of the landscape’s service infrastructure, and planning systems that cannot see them are managing some of the continent’s most valuable ecological assets as if they were not there.

Subject of Research: Effects of linear semi-natural landscape elements on regulating ecosystem services in agricultural landscapes

Article Title: As green infrastructure, linear semi-natural habitats boost regulating ecosystem services supply in agriculturally-dominated landscapes

Article References: Lange, S., Mockford, A., Burkhard, B., Müller, F., & Diekötter, T. (2023). As green infrastructure, linear semi-natural habitats boost regulating ecosystem services supply in agriculturally-dominated landscapes. One Ecosystem, 8, Article e108540. https://doi.org/10.3897/oneeco.8.e108540

Image Credits: AI Generated

DOI: 10.3897/oneeco.8.e108540

Keywords: hedgerows, green infrastructure, ecosystem services, pollination, nutrient regulation, agricultural landscapes, InVEST, Schleswig-Holstein, landscape ecology, soil erosion, water flow regulation, biodiversity

Forests cover roughly a third of Bulgaria’s territory and supply about 85 percent of the country’s water flow, making them central to national well-being. Yet detailed, municipality-level knowledge of forest ecosystems has been scarce. Before this study, only two papers had ever addressed the forest vegetation of Breznik, both dating back decades. The new work set out to close that gap by producing a complete habitat map following the European Nature Information System, or EUNIS, the classification framework used across Europe for habitat inventories, monitoring and protected area management.

The research combined old records with fresh fieldwork. The team started with data from the Ministry of Environment and Water and from Forestry Management Plans, then processed forest habitat polygons spatially using ArcGIS 10.8.1 software. During the 2021 field season, they collected 150 vegetation relevés following the classic Braun-Blanquet approach and verified vegetation types at an additional 135 GPS points, recording coordinates with a Trimble Juno device and checking everything against the latest orthophoto imagery. The final map was drawn at a scale of 1:5000, with polygons merged, deleted, created and redrawn as the evidence demanded. Habitat types were assigned using the EUNIS-ESy expert system integrated into the JUICE 7.1 software.

The result: eight distinct EUNIS forest habitat types, mapped across 322 polygons covering 147.51 square kilometers. The dominant tree species across the municipality’s natural and semi-natural forests are sessile and Hungarian oaks, European beech and hornbeam, the classic broadleaved combination of the Bulgarian semi-mountains. But the single most widespread habitat type turned out not to be natural forest at all. Coniferous plantations of site-native trees, mainly Austrian pine and Scots pine, cover 64.9 square kilometers, spread across 189 polygons in the northern, western and southern parts of the municipality.

Those pine plantations tell a story of mid-twentieth-century desperation. Planted in the 1950s through 1970s to battle soil erosion, they now occupy terrain that had been cleared for pastures decades earlier. On eroded carbonate terrains with shallow soils, the black pines struggle, averaging just three to five meters in height and forming semi-open stands. Some polygons have burned or been heavily logged and are transitioning into woodland-shrub complexes dominated by downy oak, manna ash and cornel. The second-largest habitat type, the Carpinus and Quercus mesic deciduous forest at 35.2 square kilometers, occupies northern and western slopes between 600 and 1000 meters, forming closed-canopy stands of hornbeam and sessile oak with a characteristically sparse herb layer.

Beech forests split into two ecologically different worlds. On the limestone and dolomite substrates of the southwest, beech woods on non-acid soils cover 32.3 square kilometers and shelter a species-rich herb layer that includes orchids such as bird’s-nest orchid, lady orchid and white helleborine. On the acidic magmatic and volcanic rocks of Viskyar Mountain in the northwest, beech forests on acid soils cover just 4.6 square kilometers, with wood anemone relatives and sweet woodruff characterizing the ground flora. Thermophilous oak forests dominated by Turkey oak, Hungarian oak and downy oak occupy the warm, dry southern and eastern exposures, complete with a distinct layer of bryophytes and lichens.

The most sobering finding concerns the plantations of non-native species. Artificial forests, both with site-native and non-native trees, occupy roughly 45 percent of the municipality’s total forest area, a legacy of intensive afforestation campaigns in the 1960s through 1980s. Among them are stands of black locust and northern red oak, planted in the last 50 to 70 years to stop erosion but now recognized as problematic. Black locust in particular is invasive, and the researchers found it degrading riparian zones along the Konska River, where it crowds into floodplain forests of brittle willow and black alder alongside other invaders like false indigo and Canadian horseweed. A single 0.11-square-kilometer stand of Douglas fir, another North American import, represents the rarest habitat type in the municipality.

The fieldwork delivered a blunt verdict: most of Breznik’s forest habitats are not in favorable condition. The pressures are both human and natural. Cutting, afforestation with non-native and invasive species, and pollution have altered stand structure and composition, while fires, erosion, pest outbreaks and climate-driven droughts compound the damage. Xerothermic oak forests are turning into shrublands or mixing with invading black pine, and the riverine willow forests are damaged almost everywhere. In some areas, prolonged exploitation has converted once-productive forests into coppice stands or shrubland grazed by livestock, echoing observations from the 1980s that only remnants of natural forest survived on eastern Viskyar Mountain.

The authors argue that the remedy lies in updated forestry practice. They call for measures to sustain natural forest regeneration, for afforestation programs to switch from non-native to native species, and for the introduction of invasive trees to be halted outright. Reducing pressure on forests, they note, is essential to curb degradation and the loss of species richness. Even the maligned black locust plantations have a silver lining, providing honey resources for wild pollinators, but the researchers are clear that ecosystem services do not offset the ecological cost.

Beyond its local significance, the study demonstrates a method that could be replicated across Bulgaria and beyond. Municipality-scale habitat maps at 1:5000 are an essential foundation for modeling and assessing ecosystem condition and services, and for giving policymakers the fine-grained evidence that coarse national maps cannot provide. For Breznik, the map is both a diagnosis and a baseline: a precise record of what grows where today, against which the recovery, or continued decline, of these forests can be measured in the decades to come.

Subject of Research: Forest habitat diversity and EUNIS-based mapping of Breznik municipality, western Bulgaria

Article Title: Forests of Breznik municipality

Article References: Grigorov, B., Velev, N., Assenov, A., Nazarov, M., Genova, B., & Vassilev, K. (2022). Forests of Breznik municipality. BioRisk, 17, 367-377. https://doi.org/10.3897/biorisk.17.77388

Image Credits: AI Generated

DOI: 10.3897/biorisk.17.77388

Keywords: forest habitats, EUNIS classification, Breznik municipality, Bulgaria, habitat mapping, beech forests, oak forests, pine plantations, invasive species, black locust, soil erosion, biodiversity conservation

The research, conducted in 2023, focused on Dhurkot rural municipality, a mandarin-growing zone lying between latitudes 28°04’08.76″N and longitudes 83°18’24.84″E at an average altitude of 1,000 to 1,500 meters. The team surveyed 80 households drawn by simple random sampling from a registered sampling frame of 385 mandarin farmers listed in the database of the Prime Minister Agriculture Modernization Project, the largest undertaking of Nepal’s Ministry of Agriculture and Livestock Development. Sample size was calculated using Cochran’s formula at a 95 percent confidence level with a 5 percent margin of error. Data collection combined structured interviews with key informant interviews and focus group discussions, and the resulting dataset was analyzed descriptively using MS Excel and SPSS version 23.0. To prioritize the problems farmers face, the researchers computed an index of importance from farmers’ ranked perceptions of each constraint.

The demographic picture that emerged is one of an aging, experienced and predominantly male farming population. Men made up 76.2 percent of respondents, and the largest age cohort, 41.3 percent, fell between 46 and 60 years old. Only 7.5 percent of those surveyed were between 18 and 30, a striking signal that young people are largely absent from the orchards. Farming experience ran deep: 62.5 percent of respondents had worked their mandarin groves for more than 15 years, while just 1.25 percent had entered the enterprise within the past five years. Educational attainment was modest, with 71.3 percent reporting only primary schooling and 2.5 percent education beyond class 10. Agriculture was the primary income source for 78.8 percent of households, and the average land holding of 0.72 hectares exceeded the national average of 0.55 hectares, though 83.75 percent of farms covered more than 0.25 hectares.

Understanding the soils themselves proved central to the study. Farmers reported three dominant soil types across the orchards: luvisols, reported by 61.25 percent of respondents; cambisols, reported by 36.25 percent; and sandy gravel soils, reported by 2.5 percent. All three are highly prone to erosion under the intense monsoon conditions of the mid-hills. Despite this, soil testing was strikingly rare. Some 72.5 percent of farmers had never conducted a soil test in their orchards, only 18.8 percent tested occasionally, and a mere 1.3 percent determined fertilizer doses based on soil tests and formal analysis. Just 15 percent had measured soil pH and only 2.5 percent had performed nutrient analysis. Instead, 21.3 percent of farmers relied on personal experience to decide fertilizer rates and 20 percent followed the recommendations of agro-input dealers, practices that risk both under- and over-application of nutrients.

Nutrient management in the orchards leaned heavily toward organic inputs. A majority of farmers, 58.75 percent, applied only organic manure, while 40 percent used an integrated nutrient management approach combining organic and inorganic sources; just 1.25 percent relied exclusively on chemical fertilizers. Farmyard manure doses rose steadily with tree age, from an average of about 4 kilograms per plant in the first year to nearly 47 kilograms per plant by the sixth year and beyond. Among chemical fertilizers, urea was the universal nitrogen source, while diammonium phosphate, single super phosphate and muriate of potash supplied phosphorus and potassium in escalating annual doses. Notably, farmers reported that organic fertilizers improved yield, fruit quality and shelf life, an observation consistent with soil nutrient trials on other crops. Micronutrients were also widely used, with 91.3 percent of respondents applying them, foliar zinc being the most common, reflecting the well-documented importance of micronutrient nutrition in citrus productivity.

The headline finding of the study is the remarkably high adoption of soil conservation practices. Fully 96.2 percent of respondents had adopted at least one conservation measure in their orchards. Terracing and cover cropping led the list at 95 percent, followed by sod culture and liming at 40 percent each, minimum tillage at 36.2 percent, contour farming at 31.3 percent, and integrated plant nutrient system adoption at 31.2 percent. Traditional techniques persisted alongside modern ones: stone bunds, mulching, terrace ditches, bamboo fencing and the planting of local trees and grasses remained common features of the hillside orchards. Mulching was overwhelmingly organic, with 85 percent of practitioners using maize straw, grasses or forest litter, applied most often yearly and timed to the dry months from December to April when soil moisture is low. Only 1.3 percent used plastic mulch, and hand-hoeing dominated weed control at 98.8 percent, with synthetic herbicides nearly absent.

Farmers themselves reported tangible payoffs from these practices. Some 55.84 percent said conservation measures had visibly reduced soil erosion on their land, 41.56 percent reported increased yields, and smaller shares noted reduced moisture stress and lower labor requirements. A strong majority, 81 percent, agreed that soil conservation practices delivered concrete economic benefits through reduced production costs and higher farm income while curbing erosion, landslides and localized fertility decline. Awareness was similarly high: 95 percent of respondents recognized soil degradation and its consequences for mandarin production, identifying heavy monsoon rainfall as the principal driver, and noting outcomes such as short-term fertility losses and higher yields of poorer fruit quality. Yet only 31.2 percent were familiar with the negative effects of chemical fertilizers on soil health, pointing to a knowledge gap in nutrient stewardship.

Adoption, however, was far from frictionless. A striking 78 percent of respondents described soil conservation practices as time-consuming and cumbersome, and only 21.3 percent, typically the more educated farmers, expressed willingness to adopt new conservation technologies. When problems were ranked, the lack of proper irrigation and quality inputs such as planting materials, fertilizers, pesticides and tools emerged as the most serious constraint, followed by diseases and pests, poor extension services regarding soil conservation, inadequate marketing facilities and annual fruit drop. Water scarcity plagued 88.2 percent of respondents, who coped through traditional drip irrigation, rainwater harvesting and improved drainage. The study also identified weak links in the wider value chain: mandarin marketing in the area was described as unorganized and prone to seasonal gluts, lacking systematic post-harvest technology, transportation and storage infrastructure.

The analysis made clear that awareness and adoption of conservation practices were shaped by a cluster of factors, including farming expertise, education, training participation, landholding size and contact with extension agents. These findings echo earlier research on technology adoption in smallholder systems, which consistently finds that extension contact and capacity building are decisive in shifting farmer perceptions. The authors conclude that strengthening the frequency and quality of extension services, delivering knowledge through radio, television, newspapers and social media down to the grassroots level, and formulating strategic plans to address the constraints farmers face are essential steps. They also recommend blending indigenous practices such as mulching, stone bunds and contour farming with modern approaches including scientific orchard layout, sod culture, sloping agricultural land technology and integrated plant nutrient management.

The stakes extend well beyond Gulmi. Citrus contributes about 21.61 percent of Nepal’s total fruit production, and mandarins alone accounted for 185,346 metric tons from 19,481 hectares nationally in the 2021/22 fiscal year, with Gulmi producing 7,164 metric tons from 597 hectares. Yet the Nepal Agriculture Research Council has warned of a broad citrus decline affecting orchards nationwide, driven in part by neglected soil and poor orchard management that stunt tree growth and invite pests and disease. With agriculture employing 57.1 percent of Nepal’s population and contributing nearly 24 percent of GDP, the fate of hillside mandarin orchards is a matter of national economic weight. This study suggests that the knowledge and the practices needed to sustain them already exist among farmers; the challenge now is to close the extension gap so that conservation becomes the rule rather than the exception across Nepal’s citrus hills.

Subject of Research: Adoption of soil conservation practices among mandarin farmers in Gulmi district, Nepal

Article Title: Adoption of soil conservation practices by mandarin ( Citrus reticulata B.) farmers in Gulmi, Nepal

Article References: Khang, K., Yadav, M., & Jha, M. K. (2024). Adoption of soil conservation practices by mandarin (Citrus reticulata B.) farmers in Gulmi, Nepal. Innovations in Agriculture, 7, 1-9. https://doi.org/10.3897/ia.2024.134984

Image Credits: AI Generated

DOI: 10.3897/ia.2024.134984

Keywords: soil conservation, mandarin orange, Nepal, citrus farming, soil erosion, Gulmi district, extension services, orchard management, terracing, mulching, integrated nutrient management, smallholder farmers

The study, published in the Spanish Journal of Soil Science, was led by Mistral Van Oudenhove of the Soil and Water Conservation Research Group at CEBAS-CSIC in Murcia, together with Pedro Pérez-Cutillas of the University of Murcia and Carolina Boix-Fayos of CEBAS-CSIC. The researchers set out to answer a deceptively simple question: was the money spent on soil conservation actually going where it was needed? To find out, they mined 54 policy documents spanning three programming periods—2000–2006, 2007–2013, and 2014–2020—covering Spain’s national Rural Development Programme plus the 17 regional programmes administered by Spain’s autonomous communities.

The CAP rests on two pillars. Pillar one covers direct agricultural payments, while pillar two funds rural development, including the agri-environmental and climate measures and forestry measures that carried most soil conservation spending. From 1992 onward, the CAP progressively decoupled subsidies from production, shifting toward environmental goals. Spain’s rural development programmes, approved by the European Commission and audited throughout their execution, became the principal vehicle for structuring these environmental policies. The researchers identified ten soil conservation measures common to all regions, mostly forestry, afforestation, and agri-environmental measures, and tracked their executed public spending through the ex-post evaluations published by the Spanish Ministry of Agriculture.

The headline numbers tell a striking story. Overall rural development budgets collapsed by 78 percent over the two decades, partly because several Spanish regions were reclassified as no longer underdeveloped relative to the EU average after the first programming period. Yet executed public spending on soil conservation measures rose by 13 percent between the first and last periods, peaking during 2014–2020 with an 18 percent increase in commitment. Soil conservation measures grew steadily heavier within shrinking rural development budgets, signaling a rising environmental perspective even as the overall rural development pot dwindled—a trend that continues under the 2023 reform, which plans 1.76 billion euros per year for rural development, of which 48.7 percent targets environmental measures.

Execution rates were generally high, with most measures close to 100 percent of programmed spending, which the authors read as evidence that farmers were willing to adopt soil conservation when measures were available and adequately funded. But the audit also exposed glaring regional failures. During 2000–2006, the Balearic Islands reported zero execution on a measure for protecting and regenerating the natural environment after initially programming over 3 million euros, and spent only 37.64 percent of programmed forestry funds. Eleven regions failed to adopt afforestation of non-agricultural lands during 2007–2013, making it the most unsuccessful measure of that period. In some cases regions skipped a measure entirely during one programming period only to program it with high execution rates in the other two, without clear justification—effectively denying their farmers access to those funds.

To test whether spending followed need, the team built a 24-variable matrix combining spending data with land use, soil condition, socio-economic, and political indicators. They applied canonical correlation analysis, a multivariate technique that finds linear combinations of variables maximizing correlations between two subsets, after checking normality with Shapiro-Wilk tests, homoscedasticity with Breusch-Pagan tests, and removing redundant variables with variance inflation factors above 5. The results showed executed public spending was moderately correlated with land use—driven mainly by irrigated utilized agricultural area and meadows—and weakly but significantly correlated with soil condition, where severe erosion and overall weighted average soil loss carried the strongest coefficients. No significant correlations emerged with socio-economic variables.

The correlations strengthened over time in an instructive pattern. The association between spending and land use peaked during 2007–2013 before easing in the last period, while the link between spending and soil condition remained stable through the first two periods and then jumped to a strong significant correlation during 2014–2020. The authors attribute this shift to the availability of national soil condition cartography, published mostly during the second programming period, including the National Soil Erosion Inventory and the Map of Land Condition in Spain. Once regions could see the data, they adapted and strengthened their spending associations—a finding the authors say underscores the importance of soil health monitoring. The problem is that much of this information is now obsolete: some regions have not had an erosion inventory update since 2002, and the desertification risk cartography relies on an aridity index calculated from 1989–2000 data.

Political influence, by contrast, proved minimal. The researchers tested days in power for the Spanish Socialist Workers’ Party, the People’s Party, and regionalist parties using Spearman’s correlation, since the exclusionary nature of governance made canonical correlation unsuitable. Neither major party showed any statistically significant correlation with soil conservation spending, suggesting the CAP’s main environmental goals remain mostly apolitical. Regionalist governments, present in only six regions, showed a positive correlation with forestry measures during the first period but negative correlations with soil conservation effort in the second and third periods—partly explainable because most regionalist-governed regions sit in northern Spain where soil conditions are better.

The 2023 CAP reform, aligned with the European Green Deal and its Farm to Fork, Biodiversity, and Soil Strategies, has folded all rural development actions into national CAP strategic plans and moved soil conservation largely into pillar one. Enhanced conditionality now makes certain practices compulsory for receiving payments, including the Good Agricultural Environmental Conditions on maintenance of permanent grassland, protection of wetlands and peat bogs, and non-productive features. Voluntary eco-schemes and agri-environmental measures remain mandatory for member states to offer but optional for farmers. In Spain’s strategic plan, only four regions—Aragon, the Canary Islands, Castile and Leon, and Navarra—have implemented the intervention on soil improvement and erosion control, while nearly half the regions have ignored reforestation and agroforestry investments. The compulsory approach has sparked conflicts in many regions, as small and medium-sized farms that are largely uncompetitive without CAP subsidies feel obliged to comply out of fear of going out of business, and the cost of adopting new techniques is identified as a major barrier to sustainable soil management.

The lessons from two decades of voluntary pillar-two spending are clear, the authors argue: when comprehensive environmental spending was made available through voluntary schemes, uptake was generally positive. They recommend that conditionality be flexible enough to adapt to regional conditions, which can be very restrictive in Spain’s semi-arid areas, and that soil conservation eco-schemes be promoted, made available, and properly funded in regions with higher soil degradation. Above all, they stress that updated soil condition databases are essential—the most recent national data is over ten years old, and some datasets rest on figures more than two decades old. Without monitoring, the information that helped regions align spending with need will quickly become useless, and the challenge of harmonizing the European Green Deal with agricultural reality will only grow harder.

Subject of Research: Soil conservation policy in Spain under the Common Agricultural Policy

Article Title: Legislating for Soil Conservation: A 20-Year Review and the New Approach of the CAP in Spain

Article References: Van Oudenhove, M., Pérez-Cutillas, P., & Boix-Fayos, C. (2025). Legislating for Soil Conservation: A 20-Year Review and the New Approach of the CAP in Spain. Spanish Journal of Soil Science, 15, Article 14733. https://doi.org/10.3389/sjss.2025.14733

Image Credits: AI Generated

DOI: 10.3389/sjss.2025.14733

Keywords: soil conservation, Common Agricultural Policy, Spain, soil erosion, European Green Deal, rural development, agriculture policy, Legislating, Soil, Conservation, Year, Review