Components of nutrients-use efficiency as influenced by legume-wheat (Triticum aestivum) sequences

A field experiment was conducted during 1993-95 to evaluate the components of nutrients-use efficiency under legume-wheat sequences involving 4 legume and 1 rice-based wheat cropping systems. Sequences having legumes resulted in higher N-use efficiency (32. 3 %), N-uptake efficiency (95.5%), N utilization efficiency (34.9%), available N- use efficiency (53%) and N available efficiency (90%) than its corresponding values under rice (Oryza sativa L.)-wheat (Triticum aestivum L. emend. Fiori and Paol.) system. Levels of N enhanced the all efficiency parameters significantly with exception to N utilization and available N-use efficiencies. P-use efficiency of legume-based systems was 11.5% more than that of rice-wheat system but P uptake efficiency of legume-wheat sequence was 2.6% less compared with the rice-wheat sequence. P available efficiency was 9.4%, more under legume base than under cereal based-Increasing levels of N, enhanced the P-use, P-uptake and available P-use efficiencies significantly K use, K uptake, available K-use and K available efficiencies of legume-based sequences were 45.7, 73.5, 57.3 and 81.5%, respectively which were more than their respective values under rice-wheat system. However, K utilization efficiency was higher in rice-wheat system (54.0%) than that under legume-wheat one (52.8%). The N application to these sequences had positive effect on K use and K uptake efficiencies.