The Effects Of Straw Returning And Nitrogen Fertilizer On The Growth,yield And Its Composition Of Japonica Rice

Wheat straw mulching has important influence on soil structure and fertility,rice dry matter production/distribution,microbial characteristics,agriculture ecology and rice yield.In this experiment,we selected the conventional japonica rice Xudao 5,and hybrid japonica rice 9 You 418 as test cultivars,there were 12 treatments,each of which was planted with 3 replicates.In order to provide the use of wheat straw mulching technology in the production of japonica rice,we measured the yield and its components,the change of dry matter production/distribution.The results are as Follows:1.Effect of straw retaining and nitrogen fertilizer on plant height and stem pod dynamics of Japonica rice:2 control of conventional Japonica rice and 4 straw returned to the field treatment,with the application of nitrogen and half of the field treatment yield is the highest,the total amount of land than nitrogen application conditions control reduction is not significant,because half of the field caused by straw return to the field,the full amount of straw returned to the field is feasible 2 control of Japonica hybrid rice and 4straws were treated with the highest yield in the field of fertilization,and the production of straw returning to field under fertilization was not significant,and it was feasible for hybrid Japonica rice to be in full quantity.2.Effect of wheat straw retaining and nitrogen fertilizer on rice yield and its components:(1)Without nitrogen fertilizer,the yield of conventional japonica rice was remarkably reduced in the half straw retaining field,but the yield was of little affected in that of total straw retaining field.With nitrogen fertilizer,yield increase was trivial compare with that of control field in half straw retaining field;the total yield was not significantly lower than that of the control field in total straw retaining field.Without nitrogen fertilizer for the case of hybrid japonica rice,the yields of the two mulching fields were lower than that of the control,and the difference was distinguishable.With nitrogen fertilizing,the yields of the two straw retaining field were lower than that of the control,but the difference was small.(2)In case of conventional japonica rice without nitrogen fertilizer,the increase or decrease of yield components to rice production in half straw retaining field was small.Under the conditions of full straw retaining,the panicles per unit area decreased compared with the control,and the difference was remarkable.The other yield components did not increase or decrease compared with the control.With nitrogen fertilizer,the component of the yield was not meaningfully increased or decreased by either half or full straw retaining when compared with the control.(3)Without nitrogen fertilizer,the yield components of hybrid japonica rice in half or total straw retaining field had no significant increase or decrease compared with the control.With nitrogen fertilizer,the increase or decrease of the yield component of the half straw retaining was not significant compared with the control.The number of spikelets per panicle reached a substantial level in total straw retaining field,while the change was not little compared with the control fields with respect to other aspects.3.Effect of wheat straw retaining and nitrogen fertilizer on dry matter weight of Japonica riceFor conventional japonica rice,its dry matter did not increase significantly during heading period,and the dry matter accumulation at maturation stage increased significantly under nitrogen-free conditions in half straw retaining field.In total straw retaining field dry matter weight did not change at the heading stage,and decreased significantly during maturation.With nitrogen fertilizer,in the heading period the dry matter increased significantly,but did not increase much in maturation stage for half straw retaining field.The dry matter weight increased significantly during heading period but there was no significant decline at maturation stage for total straw retaining field.4.Effect of straw retaining and nitrogen fertilizer on material distribution of Japonica rice plantsIn conventional japonica rice,no significant changes in total leaf,stem and sheath,panicle,and rootbiomass accumulation were observed in half or full straw retaining field without nitrogen fertilizer;dry matter accumulation at the total leaf area of the half straw retaining field was significantly increased under nitrogen fertilizing conditions.No significant increase or decrease was observed in other parts;for total straw retaining field,there was no obvious change in material accumulation in its total leaves,stem sheaths,panicles,and roots.In case of hybrid japonica rice,for both half and full straw retaining field under condition of no nitrogen fertilizing the weight of dry matter in total leaf or leaf sheath is increased,although not significantly;and the dry matter accumulation in the panicle does not increase much.The reduction of root dry matter for half straw retaining field was not obvious and in the meantime the increase for full straw retaining field is not significant either.With nitrogen fertilizer,dry weight of total leaves and leaf sheaths decreased for both partial and total straw retaining field,but not significant,and dry matter weight at the panicle and roots increased,which was not significant.