Nodulation, nutrient uptake and yield of maize + blackgram intercropping system in Vertisols under rainfed condition

A field experiment was conducted during kharif season of 2004 and 2005 at Instructional Farm of Indira Gandhi Krishi Vishwavidyalaya, Raipur (Chhattisgarh) to evaluate the nodulation pattern, nutrient uptake and yields of maize (Zea mays L.) and blackgram (Vigna mungo L. Hepper) as influenced by planting geometry and weed management in intercropping system. Number and dry weight of nodules were highest with sole blackgram. Grains plant⁻¹, pods plant⁻¹, grain yield and uptake of N, P and K of blackgram were also higher in the sole planting. The highest grain yield of maize was recorded in maize + blackgram (2: 1) system; however, maize equivalent yield and land equivalent ratio were highest under maize + blackgram (1: 1). Among the weed management practices, significantly highest number and dry weight of nodules were registered with the application of alachlor @ 2.0 kg a.i. ha⁻¹, which was followed by alachlor @ 1.5 kg a.i. ha⁻¹ + one hand weeding (HW) at 40 days after sowing (DAS). However, grain yield of both the component crops, uptake of N, P, K for blackgram and maize equivalent yield were recorded significantly higher with application of alachlor @ 1.5 kg a.i. ha⁻¹ + HW at 40 DAS.