The Effect Of Nitrogen Fertilizer Application Rate On The Rice Quality In Different Varieties

The study was conducted in the experimental farms of Yangzhou University during 2005-2006 following wheat stubble. The experiment was carried out by using 57 japonica cultivars and 13 indica cultivars, originated mostly from the single season rice cropping region in the south China, as materials under under 4 N levels including zero (0 N/666.7m2), low (10 N/666.7m2), medium (15 N/666.7m2) and high (20 N/666.7m2) to study the effect of the amount of Nitrogen fertilizer application on the physico-chemical characters and taste value of different variety rice. Based on these results, evaluation and classification of indexes were done. The main results were as follows:(1)With the increment amount of nitrogen, the brown rice rate, white rice rate and head rice rate of Indica and Japonica were all improved to some extent. Under different N levels, with extension of the growth duration, the brown rice rate,white rice rate and head rice rate were all increased.Compared to the effect of nitrogen, genotypes have a significant effect on the indexes of processed quality. Seen from the coefficient of variation, the difference during varieties was evidently under zero N level and decreased with increasing of N level.On the basis of their response to N levels, varieties could be roughly classified into three groups: insensitive genotype, intermediate genotype and sensitive genotype. Under this experiment condition, the varieties with insensitive response to nitrogen and high head rice rate were shuijing3, huaidao8, zhengdao99, zaofeng9, ninghui8, guanglingxiangjing,â…¢you98, nanjing39, R254, wanjing4003, yangfujing4928, yanyou2, xiangjingT31, wujing13, wuyunjing7, zhengdao196, zhengdao158, suxiangjing1, xiangjing20-18, 9746, 99-295, wuyu2105, 99298-2, changyou1, changyou02-6.(2) When increasing the amount of nitrogen, the chalkiness size and chalkiness degree of Indica and Japonica were all increased, chalkiness rate increased at first, and reached the highest value at medium nitrogen level, then decreased at high nitrogen level. Seen from the growth type genotype, the Indica genotypes exhibited higher chalkiness than Japonica genotypes. Three indexes of Japonica change tendency were not consistent with delaying of growth type. The chalkiness rate and chalkiness degree increased with delaying of growth type at first, and the value of early-maturing late Japonica(EMLJ) reached the highest, then the value decreased. The chalkiness size presented a tendency of medium-maturing medium Japonica(MMMJ)> late-maturing medium Japonica(LMMJ)> early-maturing medium Japonica(EMMJ)> medium-maturing late Japonica(MMLJ)> early-maturing late Japonica(EMLJ).Compared to genotypes, the nitrogen had a significant effect on the indexes of appearance quality. So varieties with good appearance quality could be acquired from using appropriate nitrogen fertilizer.Under this experiment condition, the varieties with insensitive response to nitrogen and good appearance quality were zhengdao210, wujing13, wu2401, wanjing97, suxiangjing1, xiangjingT31, 99-295; The varieties with sensitive response to nitrogen were P88S/0293,â…¡youming86, liangyoupeijiu, 381, nanjing16, fengyouxiangzhan, wu99-2, nongyu1898,wanjing4003,nanjing39, ninghui8, ningjing1, changyou02-6, T118.(3) When increasing the amount of nitrogen, the gel consistency and protein content of Indica and Japonica were all increased, and the amylase content were decreased; Seen from the growth type genotype, the Indica genotypes exhibited higher amylase content and protein content shouter gel consistency than Japonica genotypes. Among Japonica genotypes, the gel consistency and protein content decreased with delaying of growth type. The amylase content increased at first, and the value of early-maturing late Japonica(EMLJ) reached the highest, then the value decreased with delaying of growth type.Under this experiment condition, the varieties with insensitive response to nitrogen and soft gel consistency were jingdao7, yanjing204, yueguang, yanjing93538, shuijing3, yangfujing4901, ningjing1, wu2401, wanjing97; The varieties with sensitive response to Nitrogen were wu99-2, huangjingqing, nongyu1898, nanjing40, huajing2, huaidao8, zhengdao99, siyang1382, yanjing5, xujing2000, zhengdao5, yanyou1, xinghua2001-4, 863B, zhengdao196, xiangjing20-18, wujing15, zhengdao158, 99-295.By using amylase content as an index, the varieties with insensitive response to nitrogen were 381, fengyouxiangzhan, yangdao6, nanjing16, jingdao7, wu99-2, zhengdao99, 863B, wu2401, 99298-2; the varieties with sensitive response to nitrogen were wuyu2105, yueguang, huaidao8, nongken57, guanglingxiangjing, nanjing39, zhengdao210, changnongjing4, wujing15, 9746, wuxiangjing14, wanjing97, xiangjing20-18, 99-295, suxiangjing1, wuyu2105, T118, kunnong8.(4) The order of influence degree by N-fertilize of quality of rice indexes was chalkiness degree> head rice rate> gel consistency> amylase content> chalkiness rate> chalkiness size> protein content> brown rice rate> white rice rate.