Effect of tillage and weed management on productivity and nutrient uptake of maize (Zea mays)

An investigation was carried out at Palampur during rainy season of 2002 and 2003 to assess the influence of three tillage methods (zero tillage, conventional tillage and raised seed-bed) and four weed-control methods (unweeded check, acetachlor 0.75 kg/ha, acetachlor 1.25 kg/ha and atrazine 1.5 kg/ha) on nutrient uptake and productivity of maize (Zea mays L.). Zero tillage resulted in significantly higher soil-moisture content and bulk density than conventional tillage and raised seed-bed. Raised seed-bed resulted in significantly lowest count and dry matter of weeds. Compared with zero tillage, the conventional tillage and raised seed-bed methods being statistically at par, resulted in significantly higher N, P and K uptake by maize crop (18.1, 25.0 and 20.2% by the former and 16.1, 36.2 and 16.7% respectively by the latter method) and lower depletion of these nutrients by weeds (13.5, 15.6 and 10.8% by the former and 30.3, 30.3 and 29.0%, respectively by the latter method), increasing the average grain yield of the crop by 16.9 and 13.7% by these methods. Among weed-control methods, atrazine 1.5 kg/ha, being statistically on a par with acetachlor 1.25 kg/ha, significantly reduced the population and dry matter of total weeds. Compared with the unweeded check, atrazine 1.5 kg/ha and acetachlor 1.25 kg/ha, being statistically at par, significantly increased the N, P and K uptake by the crop (93.3, 105.3 and 95.4% by the former and 87.0, 88.8 and 88.9%, respectively by the latter) and lower depletion of N, P and K by weeds (79.4, 87.2 and 81.5% by the former, and 81.9, 88.7 and 83.5% respectively by the latter herbicide), increasing in the grain yield of maize by 75.2 and 71.7% by these two herbicides.