Yield Formation, Absorption And Utilization Of NPK Of Conventional Japonica Super In Yangtze River Area

In order to identify the yield formation, NPK elements content, accumulation and utilization, the accumulation and transfer amount at late growth stage of the conventional japonica super rice. A field experiments were carried out with8conventional japonica super rice varieties representative in the region of Yangtze River under seven nitrogen applying levels (0、10、12.5、15,17.5,20,22.5kg/667m2) in2011and2012on the farm of Yangzhou university. And seedlings were raised with plastic plate (3.5leaf). On this basis, the correlation between yield formation and absorption and utilization of conventional japonica super rice varieties was studied. The result could be provided theoretical and practical basis for breed improvement and selection of varieties. The main results were as follows:(1)With the increase in the amount of nitrogen fertilizer, the yield if different super rice varieties showed a trend of first increased and then decreased, the yield were highest in the rang of19.43-22.37kg/667m2N, the CK were17.49-19.92kg/667m2N respectively. The average of highest yield in two years was8.50%higher than non super japonica rice. Compared with the CK, the tillers of super rice reached the peak with an appropriate value, then decreased gently, ultimately arriving at a significantly higher rate of productive tillers to total tillers (above78%). The leaf area index, photosynthetic, potential, growth rate and net assimilation rate were low before jointing, but there was no significant difference with control; and after jointing stage were higher, the difference was significant or extremely significant. The dry matter accumulation was no extremely significant between the super rice and CK before the jointing stage, after the super rice was all higher than CK, were7.31%and6.55%higher than CK from jointing through heading and from heading through maturity, which the correspondingly proportion of dry matter accumulation were also higher than CK. The results showed that super rice could get the higher yield with the high nitrogen fertilizer.(2)Compared with the CK, the ratio of N accumulation and N accumulation of super rice before jointing stage were lower, but the difference wasn’t significant; then super rice was higher than CK at heading and maturity. The ratio of super rice were2.12%and3.16%higher than CK, accumulation were9.19%and9.26%respectively. The rate of N accumulation of super rice plant was lower than CK before jointing stage, but the difference wasn’t significant; then the super rice was higher than CK from jointing through heading and heading through maturity, was9.55%and37.04%higher than CK respectively, and the differences was significant or very significant. The N accumulation of super rice was higher than CK from jointing through heading and heading through maturity, the differences were significant or very significant. The accumulation and transformation of the leaf and stem-sheath of super rice were higher than CK, and the accumulation of panicles was also higher than CK, but the translocation conversation rate of vegetative organ of which were smaller than CK. The N utilization of super rice was highest under20N, which was42.55%, and the average of super rice was higher than non super rice, the difference was very significant. N absorption of100kg seeds of super rice was2.05kg under20N, the average was1.79(1.38-2.12) kg, it was higher than CK. Calculating the amount of N fertilizer under the machine transplanted, adjusting the ratio of the basic and tiller N fertilizer, increasing the panicle fertilizer and advancing the time was very important to improve the N uptaking and utilization of super rice.(3) Compared with the CK, the ratio of P accumulation of super rice was higher, but the P accumulation of super rice was lower at jointing stage, and the difference wasn’t significant; then super rice was higher than CK at heading and maturity. The ratio of super rice were8.82%and7.14%higher than CK, accumulation were9.43%and10.42%respectively. The rate of P accumulation of super rice plant was lower than CK before jointing stage, but the difference wasn’t significant; then the super rice was higher than CK from jointing through heading and heading through maturity, was15.79%and20.41%higher than CK respectively, and the differences were significant or very significant. The P accumulation of super rice was higher than CK from jointing through heading and heading through maturity, the differences were significant or very significant. The P accumulation and transformation of the leaf and stem-sheath of super rice were higher than CK, and the accumulation of panicles was also higher than CK, but the translocation conversation rate of vegetative organ of which were smaller than CK. The field capacity utilization of phosphorus showed super rice<CK, and the difference was significant, P absorption of100kg seeds of super rice was0.706kg under20N, the average was0.502(0.346～0.706) kg, it was significantly higher than CK. It was very important to apply the amount of nitrogen fertilizer for improving P uptaking and utilization of super rice.(4) Compared with the CK, the ratio of K accumulation of super rice was higher, but the K accumulation of super rice was lower at jointing stage, and the difference wasn’t significant; then super rice was higher than CK at heading and maturity. The ratio of super rice were5.24%and2.53%higher than CK, accumulation were4.41%and6.86%respectively. The rate of K accumulation of super rice plant was lower than CK before jointing stage, but the difference wasn’t significant; then the super rice was higher than CK from jointing through heading and heading through maturity, was7.91%and50.00%higher than CK respectively, and the differences were significant or very significant. The K accumulation of super rice was higher than CK from jointing through heading and heading through maturity, the differences were significant or very significant. The K accumulation and transformation of the leaf and stem-sheath of super rice were higher than CK, and the accumulation of panicles was also higher than CK, but the translocation conversation rate of vegetative organ of which were smaller than CK. The field capacity utilization of potassium showed super rice>CK, and the difference was significant, K absorption of100kg seeds of super rice was2.881kg,2.467(2.001～2.881) kg, it was significantly higher than CK. It was very important to apply the amount of nitrogen fertilizer for improving K uptaking and utilization of super rice.