Effects of N Fertilization on Yield and Dry Matters of High Quality Rice, Tianyou 3301

Effects of nitrogen (N) fertilization on yield and dry matter content of the high quality rice, Tianyou 3301, were studied. The results showed that the grain yield correlated to N application. The optimal N application was determined to be 205.06 kg穐m-2 for the highest yield of 10 350.83 kg穐m-2. The economical N application was 192.70 kg穐m-2 that would provide an estimated yield of 10 341.37 kg穐m-2. To produce 100 kg of the grains, the highest and the most economical N application rates were 1.98 and 1.86 kg, respectively. An optimum N application could produce more and bigger spikes, more total spikelets per m2 as well as higher seed set than otherwise. Either higher or lower application rate would result in lowered yields. Furthermore, moderate levels of the N fertilization could increase the dry matter productivity during the middle and later growth period, as well as the stored substances accumulated before the heading and the photosynthetic substances produced after the heading. The crop growth rate (CGR) had a linear correlation with the N application in field vegetative growth period. They had a parabolic correlation in the middle and late growth period. Consequently, in order to improve CGR in the middle and late growth period, heavy N fertilization needed to be implemented.