Nutrient uptake and yield of maize (Zea mays L.) in rice-maize system under tillage and weed management and impact on soil health

A field experiment comprising three different tillage methods i.e. conventional tillage (CT), minimum tillage (MT) and zero tillage (ZT) and six different weed management practices i.e. atrazine @1.25 kg/ha pre-emergence, 2,4-D @0.5 kg/ha post-emergence, atrazine @1.25 kg/ha pre-emergence + 2,4-D @0.5 kg/ha post-emergence, atrazine @1.25 kg./ha pre-emergence + hand weeding at 30 days after planting (DAP), two hoeing and weeding at 15 and 30 DAP and weedy check was conducted in split plot design with three replications during summer season of 2014 at Agronomy Main Research Farm, Odisha University of Agriculture and Technology, Bhubaneswar, Odisha, India. The crop was planted and harvested, respectively, on 21 January and 05 May in zero tilled plots and 05 February and 15 May in both minimum and conventionally tilled plots. Zero tillage gave the maximum grain yield of 6.73 t/ha and atrazine + one hand weeding gave the maximum grain yield of 7.62 t/ha, but atrazine + one hand weeding under zero tillage gave the grain yield of 8.08 t/ha. The maximum stover yield under zero tillage, atrazine + one hand weeding and atrazine + one hand weeding under zero tillage were 8.78, 9.62 and 10.10 t/ha, respectively. Among tillage practices, zero tillage recorded the maximum uptake of N, P and K by the crop and improved physico-chemical and biological properties of soil after harvest. Among weed management practices, atrazine + one hand weeding recorded the maximum uptake of N, P and K by the crop and weedy check recorded the maximum microbial biomass carbon, macro-aggregates (%), population of bacteria, actinomycetes and fungi and minimum electrical conductivity and bulk density of soil after harvest.