Tillage and Weed Management on Yield and Nutrient Uptake of Greengram under Maize-greengram Cropping System in Conservation Agriculture

Background: The cropping systems in any agro-ecological zone in the globe are driven by a number of critical issues, including rising food demands, the depletion of land and the degradation of land resources. The goal of traditional cropping methods has been to maximise crop yields. Cropping systems that take into account the new social, economic and ecological or environmental considerations are urgently needed nowadays. Due to their adaptability to diverse cropping patterns and capacity to fix nitrogen, legumes can offer prospects for continuous increases in productivity. Legume-based crop rotations help to maintain of organic matter, increase of soil nitrogen, nutrient balance, maintenance of soil physical qualities and disruption of soil-borne disease cycles. Conservation tillage is centered on minimum tillage, permanent raised beds, zero tillage with low soil disturbance and the preservation of protective plant cover or plant residues on the soil surface to prevent soil losses, stimulate microbial population and retain moisture and nutrients. Methods: Field experiment were conducted during 2019-20 and 2020-21 at the Main Research Station (MRS), GKVK, University of Agricultural Sciences, Bangalore On sandy loam soil to study the performance of Weed management in maize-based cropping system in conservation agriculture. The experiment was laid out under split plot design with five main plots on different tillage treatments i.e., Conventional tillage, Zero Tillage, Minimum Tillage, Minimum Tillage and Permanent raised bed and three sub plots of different weed management practices i.e., Chemical weed management practices, Integrated weed management practices and Unweeded Control replicated thrice. Result: Among tillage practices, permanent raised bed recorded the least total weed density and weed dry weight at harvest when compared to other tillage practices and also high seed yield, haulm yield and B: C ratio due to less weed infestation, good root growth, adequate aeration and nutrient availability compared to other tillage practices. Permanent raised beds had significantly higher nitrogen, phosphorus and potassium uptake than zero tillage. Among weed, management practices, Integrated weed management (Pendimethalin-750 g/ha (PE) + Hand weeding at 30 DAS) recorded the least total weed density and weed dry weight at harvest compared to unweeded treatment and also high seed yield, haulm yield and B: C ratio due to less weed infestation, compared to unweeded treatment. Integrated weed management resulted in significantly higher nitrogen, phosphorus and potassium uptake compared to unweeded (control).