Nitrogen use and rice yield formation response to zeolite and nitrogen coupling effects: Enhancement in nitrogen use efficiency

Objective of the article was to assess the coupling effects of zeolite (Z(0), 0 t ha(-1); Z(0.9) and Z(0.22), 10 t ha(-1) in different diameter of 0.45-0.9 mm and 0.17-0.22 mm) and Nitrogen (N-0, N-52.5, N-105, N-157.5 kg ha(-1)) application on N use, leaf area index (LAI) and rice grain yield in 2014 and 2015. Results showed that both Z(0.9) and Z(0.22) at N-105 and N-157.5 application rates could greatly enhance the biomass, dry weight of root, LAI and N uptake. However, at initial tillering stage of rice, Z decreased N content in plant for its high absorption capacity and hence lowered biomass and N uptake. The highest value of N recovery efficiency (NRE) and N use efficiency (NUE) was obtained from N(105)Z(0.22). Z input contributed to higher NRE and NUE. At N-157.5 application rate, Z(0.9) and Z(0.22) significantly increased rice grain yield by 14.6% and 15.3%, respectively. However, Z mattered little to rice grain yield at N-0 and N-52.5. There was no significant difference in rice grain yield between Z(0.22) and Z(0.9). Z(0.22) and Z(0.9) clearly increased the 1000-grain weight. N application significantly lowered unfilled grain percentage and 1000-grain weight.