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 (Z0, 0 t ha-1; Z0.9 and Z0.22, 10 t ha-1 in different diameter of 0.45-0.9 mm and 0.17-0.22 mm) and Nitrogen (N0, N52.5, N105, N157.5 kg ha-1) application on N use, leaf area index (LAI) and rice grain yield in 2014 and 2015. Results showed that both Z0.9 and Z0.22 at N105 and N157.5 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 N105Z0.22. Z input contributed to higher NRE and NUE. At N157.5 application rate, Z0.9 and Z0.22 significantly increased rice grain yield by 14.6% and 15.3%, respectively. However, Z mattered little to rice grain yield at N0 and N52.5. There was no significant difference in rice grain yield between Z0.22 and Z0.9. Z0.22 and Z0.9 clearly increased the 1000-grain weight. N application significantly lowered unfilled grain percentage and 1000-grain weight.