Effect of biofertilizer and nitrogen on wheal (Triticum aestivuvm) and their after effects on succeeding maize (Zea mays) in wheat-maize cropping system

Abstract

A study was conducted during 1997-98 and 1998-99 to evaluate the efficacy of 2 biofertilizers (Rhizobacteria and Azotobacter) and N in wheat (Tritictrm aesfivum L. emend. Fiori & Paol.) and their after effects on succeeding maize (Zea nlays L.) in wheat-maize cropping sequence at New Delhi, on a sandy loam soil analyzing low in total N and medium in available P and K. Both the biofertilizers being on par caused significant improvement in growth, yield and yield attributes and N uptake in wheat as compared to control. However, no carry over effect of these biofertilizers was observed in the following maize crop.Nitrogen application markedly increased growth and yield attributes, grain (4.30 tonnes/ha) and straw (6.40 tonneslha) yields, N uptake (101.10 kg/ha), net retums (Rs 15 535) and B: C ratio (1.45) in wheat up to 60 kg/ ha only. Application of 120 kg Nha applied to wheat significantly increased the grain yield (3.98 tonnesfha) and N uptake (1 12 kg/ha) in succeeding maize over no N. Direct applied N to maize significantly increased the grain yield (4.55 tomes/ ha) and N uptake (13 1.80 kgha) in maize up to I20 kg/ha. Over the seasons, the grain yield of maize with 60 kg Niha increased by 34.73 %over no nitrogen. The corresponding increase in yield with 120 kg N/haover 60 kg Nha was 13.78 %. Both the biofertilizers, being on par, recorded higher N uptake and net retums over no biofertilizer in wheat-maize cropping system. The uptake of N and net retums in this cropping system increased with increasing levels of residual and direct applied N to maize up to 120 kg N/ha.