In castor crop, fresh vermicompost and gliricidia loppings were applied to the soil at rates of 0, 2, 4 and 6 Mg C/ha. The carbon sequestration potential of the soils up to 40 cm depth calculated using measured values of Organic Carbon (OC) in < 20 µm soil fraction ranged from 5.73 kg/m2 in native forest land-use system to 7.72 kg/m2 in the cropping with large C input land-use system.
In maize-pigeon pea crop rotation on conservation agriculture and nitrogen management practices revealed that about 24.1 and 12.8 per cent significantly higher pigeon pea seed yield was recorded in no-tillage and reduced tillage as compared to the conventional tillage. In different aggregate size fractions, 12.2-22.9 and 5.6-10.6 per cent aggregate total carbon increase was observed in no-tillage and reduced tillage, respectively as compared to the conventional tillage.
Experiments on maize crop revealed that zeolite application increased the plant nutrient content and nutrient uptake as compared to control. The application of N @ 120 kg/ha along with zeolite application @ 4 and 8 t/ha improved the N uptake by 46.2 and 57.9 per cent over sole application of N @ 120 kg/ha.
The grain yield of sorghum in sorghum-blackgram rotation was significantly higher with crop residue retention. The treatment with higher crop residue retention recorded 27.5 per cent higher sorghum grain yield and 24 per cent higher straw yield over no residue treatment.
The pearl millet-pigeon pea (and horse gram on residual fertility) based system recorded significantly higher pearl millet grain yield in minimum tillage (2361 kg/ha) as compared to zero tillage and conventional tillage. Similarly, higher yield was observed in 125 per cent of the recommended dose of the fertilizers (2348 kg/ha) as compared to the other recommended dose of fertilizers. The cotton-pigeonpea system, pooled data of 5 years (2016-2020) revealed that significantly higher cotton equivalent yield was obtained under minimum tillage with 125 per cent recommended dose of fertilizers as compared to zero tillage.
In pigeon pea +setaria intercropping system, results revealed that zero tillage recorded 20 and 18 per cent higher pigeon pea equivalent yields as compared to conventional and reduced tillage respectively. The 10 and 30 cm height anchored residues recorded 55 and 54 per cent higher yield as compared to no residue.
Results on maize crop revealed that integration of in-situ moisture conservation practices through permanent bed and furrow, permanent conservation furrow recorded 19 and 10 per cent higher maize yields as compared to conventional tillage without moisture conservation treatment. Among the weed control treatments, pre-emergence+post emergence herbicide application recorded higher yields as compared to other weed management practices. Reduction in crop yield in un-weeded treatment in zero tillage was higher than in conventional tillage.