Soil is a natural capital which supplies valuable ecosystem services including carbon and nitrogen storage. Agroecosystems play an important role in soil organic carbon (SOC) and soil total nitrogen (NT) accumulation. The aim of this study was to analyse SOC stock (SOCS) and NT stock (NTS) in relation to land use (arable land-AL, permanent grasslands-PG), management, soil depth, and selected soil properties of six soil subtypes (Rendzic Leptosol—LPrz, Dystric Cambisol—CMdy, Stagnic Cambisol—CMst, Haplic Fluvisol—FLha, Gleyic Fluvisol—FLgl, Haplic Chernozem—CHha) which are the most widespread in Slovakia. SOCS for a 50 cm deep soil profile ranged from 161 t.ha⁻¹ in CHha to 59 t.ha⁻¹ in FLgl in grasslands, and in arable lands from 111 t.ha⁻¹ in CHha to 38 t.ha⁻¹ in CMst. In grasslands, FLs and CMst showed the significantly lowest SOCS and NTS in comparison to CMdy, LPrz, and CHha. The mean soil NT content in arable land and grasslands was 2.21 g.kg⁻¹ and 2.82 g.kg⁻¹, respectively. ANOVA showed that soil subtype, land use, and site have significantly affected SOCS but not NTS. The correlation analysis revealed correlations between SOCS and NTS. SOCS was also correlated with C:N, pH, P, and K. This study should help to encourage practices to maintain soil C and soil properties and to ensure the sustainability of the functions of many soil types in Slovakia. Full article

The restoration of soil organic matter (SOM, as measured by soil organic carbon (SOC)) within the world’s agricultural soils is imperative to sustaining crop production and restoring other ecosystem services. We compiled long-term studies on the effect of management practices on SOC from Iowa, USA—an agricultural region with relatively high-quality soil data—to highlight constraints on detecting changes in SOC and inform research needed to improve SOC measurement and management. We found that strip-tillage and no-tillage increased SOC by 0.25–0.43 Mg C ha⁻¹ yr⁻¹ compared to losses of 0.24 to 0.46 Mg C ha⁻¹ yr⁻¹ with more intensive tillage methods. The conversion of cropland to perennial grassland increased SOC by 0.21–0.74 Mg C ha⁻¹ yr⁻¹. However, diversifying crop rotations with extended rotations, and supplementing synthetic fertilizer with animal manure, had highly variable and inconsistent effects on SOC. The improved prediction of changes in SOC requires: the use of methods that can identify and disentangle multiple sources of variability; looking beyond total SOC and toward systematic collection of data on more responsive and functionally relevant fractions; whole-profile SOC monitoring; monitoring SOC in long-term studies on the effect of multiple conservation practices used in combination; and deeper collaboration between field soil scientists and modelers. Full article

The rate of change in the relative amount of active and passive carbon (AC and PC) due to the land management practices (cropping systems combined with tillage) may vary with soil types depending on their level of chemical and/or physical protection from the decomposition but has rarely been directly measured. We have quantified the C storage potentiality of different soil types, namely old alluvial Inceptisol of Malda and recent alluvial Entisol of Coochbehar in West Bengal (subtropical eastern India) under the influence of different cropping systems (rice-maize: RM and rice-wheat: RW) and tillage practices (zero-tillage: ZT and conventional tillage: CT). The key objective was to demonstrate the short-term impact of conservation agriculture (CA) on soil C dynamics over the conventional practice. Research revealed that after short-term CA, total organic carbon (TOC), AC, PC, and total nitrogen (TN) showed significant (p < 0.05) improvement under the RM cropping system over the RW. The highest TOC content under the RM cropping system was recorded in the sites of Malda over the Coochbehar sites. The ZT significantly (p < 0.05) enhanced the TOC in the upper layers (0–5 and 5–10 cm) and the CT showed improvements in the lower depths (10–20 cm). We observed some irregular variations in the interactions of the cropping system and tillage with respect to different sites. However, the ZT performed better in improving C fractions under RM and RW as compared to CT. The TOC and TN stocks were maximum in the lower depth which was evident in both soil types. The TOC linearly regressed on TN accounted for 94.2% variability (R² = 0.942) of the C accumulation in soil and vice-versa. The PC was in a significant relationship with TN (R² = 0.943), but AC was moderately regressed (R² = 0.851). Lower stratification ratio values in Coochbehar soils (sandy loam in texture) indicated higher profile distribution of AC and PC in the soil profile; while in the Inceptisol, accumulation of the C fractions on the soil surface due to heavy texture resulted in the higher stratification values. The novelty of this study is that old alluvial Inceptisol showed a comparatively greater amount of AC and PC storage capability in comparison with the new alluvial Entisol. Conclusively, our study demonstrated that the adoption of conservation agriculture (CA practice/ZT) in cropping systems with higher C biomass input would significantly enhance the AC and PC fractions; however, the amount of storage is highly governed by the soil type and climatic factors. Full article

Soils are at the nexus of the atmospheric, geological, and hydrologic cycles, providing invaluable ecosystem services associated with water provision. The immeasurably vital role of water provision is of urgent concern given the intertwined and interdependent challenges of growing human populations, increased agricultural demands, climate change, and freshwater scarcity. Adapting temperate rain-fed cropping systems to meet the challenges of the 21st century will require considerable advancements in our understanding of the interdependent biophysical processes governing carbon and soil-water dynamics. Soil carbon and water are inextricably linked, and agricultural management practices must take this complexity into account if crop productivity is to be maintained and improved. Given the widespread, intensive use of agricultural soils worldwide, it stands to reason that readily adaptable crop management practices can and must play a central role in both soil carbon and water management. This review details challenges and opportunities for utilizing cover crop management to enhance soil carbon stocks and soil water use efficiency in rain-fed cropping systems. A review of the current body of knowledge shows that cover crops can play a more prominent role in soil carbon and water management; however, the more widespread use of cover crops may be hindered by the inconsistencies of experimental data demonstrating cover crop effects on soil water retention, as well as cover crop effect inconsistencies arising from complex interactions between soil carbon, water, and land management. Although these gaps in our collective knowledge are not insignificant, they do present substantial opportunities for further research at both mechanistic and landscape-system scales. Full article