Nutrient uptake appraisal of maize intercropped with legumes and associated weeds under the influence of weed control

Field experiments were conducted during rainy seasons of 2001 and 2002 to evaluate the uptake of major primary nutrients by maize legume intercropping system under the influence of weed control. Maize intercropped with cowpea and soybean produced significantly lower weed dry matter and NPK depletion by them. All intercropping systems produced higher biological yield of crops. Maize + soybean resulted in higher N uptake while all intercropping systems were at par and resulted in significantly higher P uptake than sole maize. While K uptake by crops was unaffected by intercropping systems. Weed control through pre-emergence application of metolachlor 1 kg ha⁻¹, alachlor 2 kg ha⁻¹ and hand weeding at 30 DAS significantly reduced the weed dry matter and NPK uptake by them. These treatments also increased the total biological yield of crop and their total NPK uptake.