Disentangling the effect of environmental factors on yield and nitrogen uptake of irrigated rice in Asia

With normalized root mean square errors (RMSEn) of 6-16%, ORYZA2000 satisfactorily simulated crop biomass, yield, N uptake, and INUE, that strongly varied among genotypes and locations. Environmental factors contributed differentially to yield, N uptake, and INUE, and their contributions were modified by N management. Indigenous soil N supply affected yield and INUE more strongly than weather conditions at low fertilizer N rates, but its influence was less pronounced at higher fertilizer N rates. Under both, low and high fertilizer N rates, indigenous soil N supply affected N uptake more than weather conditions did. Temperature contributed more than radiation to the variation in yield, N uptake, and INUE. Results suggest that N fertilizer management should take into account indigenous soil N supply, while temperature is the major factor in the selection of genotypes and sowing dates in maximizing rice yield.