| Effects of nitrogen fertilizer application on yield, quality and characters of nitrogen absorption in double-cropping rice were studied in the farm of Agricultural Institute of Ganzhou in Jiangxi Province during 2005~2006. The study took early rice Jinyou 463 and late rice Xieyou 46 and Tianyou 998 as test materials. The total amount of nitrogen application was 15 kg/667m2 in whole growing stages, nitrogen application at the earlier stage (basic-tilling fertilizer) and middle-later stage (stem-booting fertilizer) respectively were in a ratio of 10:0, 8:2, 7:3, 6:4(1), 5:5(1), 6:4(2) and 5:5(2). The main results were as follows:1. Under the same total amount of nitrogen fertilizer with different ratio, the treatment 7:3 achieved the highest yield both in early rice and late rice. It was 517.83 kg/667m2 and 536.75 kg/667m2 respectively. The yield of the treatment 6:4 was the second, those were all more than that of conventional nitrogen pattern (early rice yield of 10:0 was 473.12kg/667m2 while late rice yield of 10:0 was 498.47kg/667m2). The yield of treatment 5:5 increased a little more than 10:0, the yield of treatment 6:4 and 5:5 which stem-booting fertilizer was used one time were slightly higher than that of twice used. The sequent of the yield of Jinyou 463 and Tianyou 998 from high to low in different proportion of nitrogen treatment was as follows 7:3, 6:4, 5:5, 8:2, 10:0.2. The result of this test showed that the effect of nitrogen application mode on grain quality was in accord with past conclusion. Increasing proportion of nitrogen in later stage could improve the milling quality. It was complex that nitrogen fertilizer proportion affected external quality. With the nitrogen ratio of later stage increasing, chalkiness and chalkiness ratio declined gradually. The effect on amylose and protein content were insignificantly, with increasing nitrogen ratio of middle-later stage, the protein content increased, while the amylose showed the opposite tendency, gel consistency increased slightly. When the proportion of nitrogen treatment was 7:3 and 6:4, every index of quality was relatively excellent.3. Reasonable tiller dynamic development and high ratio of spikes to tillers were the important index of group quality. The treatment with higher proportion of nitrogen application in the earlier period had large number of maximum of tillers, but its yield wasn't high because of little nitrogen fertilizer at later stage. Smaller proportion of nitrogen application in earlier stage, the colony of plant developed smaller, with the large percentage of panicle nitrogen on later stage, it promoted the emergence of the invalid tillers, its yield was also not high. The colony of 7:3 and 6:4 were relatively rational, the ratio of spikes to tillers were also relatively high.4. Study showed that there existed significant linear correlation between the distribution of nitrogen fertilizer and dry matter of stage of remaining leaf primordium number 3, and quadratic correlation with the dry matter of heading stage and maturity stage. Dry matter of treatment 7:3 was higher than other treatments at heading stage and maturity stage, its dry matter of maturity stage was that early rice was 932.85kg/667m2 and late rice was 1009.43 kg/667m2. Under the high yield condition, there existed significant linear correlation between dry matter from heading stage to maturity stage and its yield, its relevant degree was higher than other stages. The ratio of dry matter from heading stage to maturity stage to dry matter of maturity stage of the treatment 7:3 was higher; the percentage of dry matter from heading stage to maturity stage to yield was also high.5. With the nitrogen proportion at earlier stage increasing, nitrogen content of stage of remaining leaf primordium number 3 was gradually greater, while that of heading stage and maturity stage decreased gradually in both early rice and late rice. The amount of nitrogen absorption of plant had the same tendency as nitrogen content.There existed parabola correlation between the amount of nitrogen absorption from heading stage to maturity stage and its ratio to total nitrogen absorption in maturity stage and the proportion of nitrogen application at earlier and later stage, however linear correlation with the amount of nitrogen absorption from stage of remaining leaf primordium number 3 to heading stage. The treatment 7:3 had suitable nitrogen absorption in stage of remaining leaf primordium number 3 to heading stage and heading stage to maturity stage, its amount of nitrogen absorption of maturity stage was that early rice was 10.46kg/667m2 and late rice was 10.99kg/667m2.With the decreasing of the nitrogen application proportion at earlier stage, the nitrogen utilization efficiency and the N-agronomy efficiency increased. Under this experimental condition, the double-cropping rice with the nitrogen treatment of 7:3 and 6:4 would get higher yield, nitrogen utilization efficiency and the N-agronomy efficiency. As the treatments had the same amount of phosphorus and potassium application, the tendency of different treatment was insignificant. The higher nitrogen absorption was beneficial to the absorption of phosphorus and potassium.6. The result showed that, in the period of spike differentiation of the double-cropping rice, studying qualitative analysis on the fourth and the third leaf from the top and quantitative analysis on the nitrogen content of leaf blade, determining the corresponding period SPAD value of the blade, they were all consistent with the changes of the leaf color, it would be the basis of the using panicle fertilizer. A large amount of non- structural carbohydrate of plant were formatted and hydrolysised in period of spike differentiation and then the material and energy for bud differentiation were constantly offered, the content of the soluble sugar of the stem sheath played an important role in starting and promoting the grain filling. The nitrogen application had an important influence on coordinating the carbon and nitrogen metabolism.
|
PDF Full Text Request