Triple-zero tillage and system intensification lead to enhanced productivity, micronutrient biofortification and moisture-stress tolerance ability in chickpea in a pearlmillet-chickpea cropping system of semi-arid climate

Productivity, soil health, and carbon management index of soybean-wheat cropping system under double zero-tillage and natural-farming based organic nutrient management in north-Indian plains

Conservation-agriculture and organic-farming are two sustainable-agriculture approaches to ensure food security and environmental-sustainability. Hence, a field study assessed the productivity, soil-health and carbon-dynamics of soybean-wheat cropping system (SWCS) under four tillage and residue-management practices (TRMPs) viz., Conventional-tillage without residues (CT-R), conventional-tillage with residue-retention in both crops at 3 t ha-1 each (CT + R), zero-tillage without residues (ZT-R), and zero-tillage with residue-retention in both crops at 3 t ha-1 each (ZT + R); and five organic-nutrient-management-practices (ONMPs) in both crops viz., 100 % RDF (N1), 100 % RDN through FYM (N2), 100 % RDN through VC (N3), 100 % RDN through FYM + Biofertilizers + Cow-urine + Panchgavya + Jeevamrut (N4), and 100 % RDN through VC + Biofertilizers + Cow-urine + Panchgavya + Jeevamrut (N5), in split-plot-design replicated-thrice. Among TRMPs, ZT + R enhanced system-productivity (SEY) by ∼17.2 % over CT-R, besides improved soil available-N, P, K by 6.4, 6.5 and 6.5 %, respectively. SMBC, SMBN and SMBP were higher under ZT + R by 16.2, 21.5 and 10.8 % over CT-R, respectively. ZT + R had higher soil enzyme activities of DHA, Acid-P, ALP, URA, and FDA over CT-R by 19.4, 20.7, 21.5, 20.7 and 15.2 %, respectively. ZT + R also had higher VLC, ACP, LI and CMI over CT-R. Among ONMPs, the natural-farming based ONMP, N5 considerably improved SMBC, SMBN, SMBP, FDA, DHA, Acid-P, URA, and ALP by 12.7-12.9 % over N1 (100 % RDF). ONMP-N5 improved the available-N, P, K content over N1 by 6.6, 5.8 and 6.7 %, respectively. ONMP-N5 had higher (p < 0.05) microbial-count, VLC, APC, LI and CMI; however, system-productivity was ∼4.1 % lower than N1 in this two-years' short-study which further need investigation in multi-location long-term experiments. Overall, the dual-crop basis ZT + R at 6 t ha-1 year-1 + NF-based ONMPs (N5) may harness higher and sustained productivity under SWCS besides advancing soil-health and soil carbon-pools in sandy-loam soils of north-Indian plains and similar soils across south-Asia.

High-value crops' embedded groundnut-based production systems vis-à-vis system-mode integrated nutrient management: long-term impacts on system productivity, system profitability, and soil bio-fertility indicators in semi-arid climate

The current study identified two new climate-resilient groundnut-based cropping systems (GBCSs), viz., groundnut-fenugreek cropping system (GFCS) and groundnut-marigold cropping system (GMCS), with appropriate system-mode bio-compost embedded nutrient management schedules (SBINMSs) for semi-arid South Asia. This 5-year field study revealed that the GMCS along with leaf compost (LC) + 50% recommended dose of fertilizers (RDF50) in wet-season crop (groundnut) and 100% RDF (RDF100) in winter-season crop (marigold) exhibited the highest system productivity (5.13-5.99 t/ha), system profits (US$ 1,767-2,688/ha), and soil fertility (available NPK). Among SBINMSs, the application of 5 t/ha leaf and cow dung mixture compost (LCMC) with RDF50 showed the highest increase (0.41%) in soil organic carbon (SOC) followed by LC at 5 t/ha with RDF50 and RDF100. Legume-legume rotation (GFCS) had significantly higher soil microbial biomass carbon (SMBC) and soil microbial biomass nitrogen (SMBN) than legume-non-legume rotations (groundnut-wheat cropping system (GWCS) and GMCS). Among SBINMSs, the highest SMBC (201 µg/g dry soil) and SMBN (27.9 µg/g dry soil) were obtained when LCMC+RDF50 was applied to groundnut. The SMBC : SMBN ratio was the highest in the GWCS. LC+RDF50 exhibited the highest SMBC : SOC ratio (51.6). The largest increase in soil enzymatic activities was observed under LCMC+RDF50. Overall, the GMCS with LC+RDF50 in the wet season and RDF100 in the winter season proved highly productive and remunerative with better soil bio-fertility. SBINMSs saved chemical fertilizers by ~25%' in addition to enhanced system productivity and system profits across GBCSs in semi-arid regions of South Asia. Future research needs to focus on studying the potential of diversified production systems on water and environmental footprints, carbon dynamics, and energy productivity under semi-arid ecologies.

Elucidating the interactive impact of tillage, residue retention and system intensification on pearl millet yield stability and biofortification under rainfed agro-ecosystems

Micronutrient malnutrition and suboptimal yields pose significant challenges in rainfed cropping systems worldwide. To address these issues, the implementation of climate-smart management strategies such as conservation agriculture (CA) and system intensification of millet cropping systems is crucial. In this study, we investigated the effects of different system intensification options, residue management, and contrasting tillage practices on pearl millet yield stability, biofortification, and the fatty acid profile of the pearl millet. ZT systems with intercropping of legumes (cluster bean, cowpea, and chickpea) significantly increased productivity (7-12.5%), micronutrient biofortification [Fe (12.5%), Zn (4.9-12.2%), Mn (3.1-6.7%), and Cu (8.3-16.7%)], protein content (2.2-9.9%), oil content (1.3%), and fatty acid profile of pearl millet grains compared to conventional tillage (CT)-based systems with sole cropping. The interactive effect of tillage, residue retention, and system intensification analyzed using GGE statistical analysis revealed that the best combination for achieving stable yields and micronutrient fortification was residue retention in both (wet and dry) seasons coupled with a ZT pearl millet + cowpea-mustard (both with and without barley intercropping) system. In conclusion, ZT combined with residue recycling and legume intercropping can be recommended as an effective approach to achieve stable yield levels and enhance the biofortification of pearl millet in rainfed agroecosystems of South Asia.