Study On Yield And Quality Of Japonica Rice Under Dry Direct Seeding And Transplanting Conditions

High-yield and high-quality cultivation of rice has been a hot research topic in recent years.The rapid development of direct-seeding rice research has been promoted by the development of urban and rural economy,the change of labor force and the breakthrough of cultivation techniques.In this study,Shendao 702,a Medium-maturing semi-erect panicle rice strain,was used as the test material.Two-factor split plot design was adopted in the experiment.The main plot was cultivation mode,including direct seeding and transplanting.The split plot was yield level,including basic fertility yield(BY),farmer yield(FY),high-yield and high-efficiency yield(HH)and Super-high-yield(SH).The changes of grain number,seed setting rate,effective panicle number,primary branch,secondary branch and1000-grain weight,light transmittance of population structure,leaf area index and SPAD,photosynthesis,nitrogen use efficiency and transport rate,processing quality,appearance quality and cooking nutrition quality of rice quality indicators were studied.The change rule of taste quality.The results show that:(1)under transplanting and direct seeding,the number of grains per panicle,the number of effective panicles and yield increased with the increase of nitrogen fertilizer application,but the seed setting rate was on the contrary,and the 1000-grain weight increased and then decreased;the primary and secondary branches were lower under SH treatment.Under the same fertility yield level,compared with transplanting,the number of grains per panicle,effective panicles and yield per Panicle under dry direct seeding condition were lower,while the seed setting rate and 1000-grain weight were the opposite for primary and secondary branches.(2)under the condition of transplanting,the agronomic efficiency of nitrogen and the productivity of partial factors of nitrogen increased first and then decreased with the increase of fertility yield level;under the condition of direct seeding in drought,the agronomic efficiency of nitrogen and the productivity of partial factors of nitrogen increased with the increase of fertility yield level;under the condition of transplanting and direct seeding in drought,the accumulation of nitrogen and the recovery utilization rate of nitrogen increased continuously,while the nitrogen translocation rate increased and then decreased.?(3)under the conditions of transplanting and direct seeding,the SPAD value of rice leaves and leaf area index increased with the increase of fertility yield,while the population light transmittance was just the opposite.The net photosynthetic rate and stomatal conductance increased with the increase of fertility yield under transplanting and direct seeding conditions.(4)under the conditions of transplanting and direct seeding,the processing quality index of rice did not change significantly with the increase of fertility yield,but the appearance quality index changed significantly.The chalky interest rate and chalkiness value increased,protein content increased,amylose decreased,the taste value of transplanted rice decreased,direct seeding rice increased first and then decreased,and the appearance,viscosity and balance of rice increased first and then decreased.Under the same fertility yield level,the chalky interest rate,chalkiness and transparency of dry direct seeding rice were higher than those of transplanted rice,and the contents of protein and amylose were relatively higher.