Switchgrass (Panicum virgatum L.) has the potential to recover the soil hydrological properties of marginal lands. Nitrogen (N) and landscape position are the key factors in impacting these soil properties under switchgrass. The specific objective of this study was to investigate the responses of N rate (low, 0 kg N/ha and high, 112 kg N/ha) and landscape positions (shoulder and footslope) on near‐surface soil hydrological properties that included: infiltration rate (qs), saturated hydraulic conductivity (Ksat), bulk density (ρb), penetration resistance (SPR), water retention (SWR), pore‐size distribution (PSD), and carbon (C) and nitrogen (N) fractions under switchgrass production. Data showed that, in general, the N and landscape position significantly influenced soil hydrological properties. Higher N rate decreased ρb (1.23 and 1.36 g/cm3 at 0–5 and 5–15 cm, respectively) and SPR (1.06 and 1.53 MPa at 0–5 and 5–15 cm, respectively) at both depths and increased the qs, Ksat and Green–Ampt estimated sorptivity (S) and hydraulic conductivity (Ks) parameters, and SWR (0–5 cm depth) at 0 and −0.4 kPa matric potentials (ψm). Furthermore, footslope position significantly decreased ρb, SPR at 0–5 and 5–15 cm depths, and increased the qs, Ksat, S, Ks, and SWR (0–5 cm depth) at every ψm ranged from 0 to −30.0 kPa. The higher N rate increased the coarse mesopores (60–1,000 μm) and total pores, whereas, footslope position increased the coarse mesopores, micropores (<60 μm), and total pores. Data from this study showed that planting switchgrass with 112 kg N/ha under footslope position helped in improving the soil hydrological properties, those can be beneficial in enhancing the biomass yield under marginal lands.

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Repeated puddling for rice cultivation and extensive tillage during wheat cultivation in the north-west of India has adversely affected soil health. Adoption of resource conservation technologies (RCTs) is required for long-term sustainability of conventional rice–wheat systems. However, the behaviour of these technologies is site-specific. A field study was conducted in 2016 to evaluate the medium-term impact of tillage and residue retention on soil physical and biological characteristics. Four treatments were imposed during 2011: conventionally-tilled (CT) rice followed by CT wheat all without residue retention (–M); zero-tilled (ZT) rice followed by ZT wheat and –M; CT rice followed by CT wheat and all with residue retention (+M); and ZT direct-seeded rice followed by ZT wheat and +M. In the surface layer (0–15 cm) of ZT, soil organic carbon (SOC) stock was higher by 15%, mean weight diameter (MWD) by 31.8% and bulk density (BD) by 4% compared to CT averaged across residue treatments. Irrespective of tillage, SOC stock was increased by 19% and MWD by 39% and BD decreased by 1.8% in +M compared with –M in the 0–15 cm soil layer. Infiltration rate was higher in +M than –M irrespective of tillage. Microbial biomass carbon, basal soil respiration and soil enzymatic activities were higher in ZT and +M than CT and –M respectively. Thus, medium-term adoption of RCTs such as ZT and residue retention enhanced soil physical and biological properties in this dry-seeded rice–wheat system. However, whether retaining wheat residue improves soil physical and biological properties requires further investigation.

Integration of cover crops and livestock (ICLS) in an existing corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] cropping system can be an effective strategy to improve soil physical and hydrological properties. Three on-farm long-term (≥30 yr) sites (Sites 1, 2 and 3) and one short-term (3 yr) experimental site (Site 4) with a randomized block design in eastern South Dakota were selected to evaluate the impacts of ICLS on soil physical and hydrological properties. At Sites 1, 2, and 3, the following long-term management systems were compared: ICLS (corn/grazing-soybean/grazing-cover crop/grazing), control (CNT, corn-soybean with no cover crop and no grazing), and a grazed pasture (GP). At Site 4, the treatments included ICLS (corn/grazing-soybean/grazing-oat [Avena sativa L.]-cover crop/grazing], cover crop (corn-soybean-oat-cover crop with no grazing), CNT (corn-soybean-oat without cover crop and grazing), and GP. Data showed that soil organic carbon (SOC) was higher by 20-26% and bulk density was lower by 18-37% in long-term ICLS compared with CNT. Long-term ICLS also improved soil water retention, macroporosity, infiltration rate, and total porosity compared with the CNT.However, these properties were not affected by short-term ICLS at Site 4. The GP had the lower soil bulk density and higher SOC and infiltration rate compared with ICLS and the CNT except at Site 4. This study showed that long-term integration of cover crops and livestock grazing under ICLS can be beneficial in enhancing soil physical and hydrological properties. However, whether such integration improves other soil quality parameters and crop yield requires further investigation.

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Context Labile soil C and N fractions are strongly influenced by agricultural management practices. Aims This study was conducted on three long-term (≥30 years) on-farm sites (sites 1–3), and one short-term (3 years) experimental site (site 4) to evaluate the impacts of integrated crop–livestock system (ICLS) on labile C and N fractions and β-glucosidase enzyme activity for the 0–5 cm soil depth. Methods Long-term management systems (ICLS, corn (Zea mays L.)/grazing–soybean (Glycine max (L.) Merr.)/grazing–cover crop/grazing), control (CNT, corn–soybean with no cover crop and no grazing), and a grazed pasture (GP) at sites 1–3 were compared. At site 4, the treatments included: ICLS (corn/grazing–soybean/grazing–oat (Avena sativa L.)–cover crop/grazing); CC (corn–soybean–oat–cover crop with no grazing); CNT (corn–soybean–oat–fallow with no grazing); and GP. Key results ICLS had higher hot water extractable organic carbon (HWC), cold water extractable organic carbon (CWC), microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), potential carbon mineralisation (PCM) and potassium permanganate oxidisable carbon (POXC) than CNT under long-term management system. Long-term ICLS also enhanced β-glucosidase activity compared to CNT. ICLS had 72%, 214% and 60% higher glucosidase activity than the CNT at sites 1, 2 and 3, respectively. However, the C and N fractions and β-glucosidase activity were not affected by short-term ICLS (site 4). GP always had higher C and N fractions than ICLS and the CNT. There was a significantly positive relationship between SOC and labile C and N fractions, except POXC. Conclusions and implications Long-term inclusion of cover crops and livestock grazing in corn–soybean system was effective in enhancing labile soil C and N fractions.

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