Crop yield stability and sustainability in a rice-wheat cropping system based on 34-year field experiment

Abstract

Abstract Little is known about the effects of different fertilizers and manure use on the yield stability and sustainability of crop in a rice-wheat cropping system. Therefore, a 34-year field experiment (conducted from 1982 to 2015) was used to evaluate the effect of continuous application of inorganic fertilizers and organic manure, supplied at different combinations, on the stability and sustainability of rice and wheat yields. Eight treatments consisted of unfertilized control (CK), inorganic fertilizers (N, NP, NPK) and organic manure (M) either alone or in combination (MN, MNP, MNPK). There was no significant trend of rice grain yield over time for any of the treatments. Wheat yield had an increasing tendency in all the fertilization treatments, including the unfertilized control. Organic manure in combination with chemical fertilizer supported high rice and wheat yields and sustainable yield index (SYI), with decreased coefficient of variance (CV) of rice and wheat yields. The SYI value clearly indicates that rice yield was more sustainable than wheat yield. In conclusion, the combined use of both organic manure and inorganic fertilizer can improve not only crop grain yield but also yield stability and sustainability.