Effect Of Different Cultivation Modes On The Yield And Grain Quality Of Double Season Rice

Rice (Oryza saliva L.) is the main food crop in China. The grain yield and grain quality are equally important for rice cultivation. There are lots of studies about the effect of single cultivation factor on rice grain yield and quality, but the comprehensive effect of cultivation factors on grain yield and quality was rare. In the study, an early rice variety'Zhongjiazao 17', two late rice varieties'Yongyou 8'and 'Tianyouhuazhan'were grown under five different treatments including no nitrogen fertilizer treatment (T1), local farmers'practice treatment (T2), and 3 comprehensive treatments with integrated agronomic practices including the higher yield and higher profits treatment (T3),the super high yield treatment (T4), and the further more yield and profit treatment (T5). Field experiments were conducted continuously during the early season and late season of 2013-2014 at Yongan town in Liuyang County, Hunan Province. The main results are as follows:(1) Different cultivation patterns significantly affect rice grain yield and yield components of double season rice. The yield under T3-T5 by integrating agronomic practices was significantly higher than that under T2 (farmers' practice). The yield of Tianyouhuazan' under T3, T4 and T5 were 12%,23.6%,13.3% higher than that under T2 in 2013, respectively; the yield of'Zhongjiazao 17'and'Yongyou 8'under T3, T4 and T5 were 10.1%,16.2%.23.3% and 10.8%,16.8%,7.5% higher than that under T2 in 2014. respectively. The results of yield component analysis showed that the yield improvement under T3?T5 was due to significantly increased panicles m-2 and stable grain-filling percentage and 1000 grain weight.(2) Grain quality traits were different under different cultivation patterns. The eating and cooking quality traits including amylase content, gel consistency and gelatinization temperature and appearance quality were not significantly affected among T3?T5 in double season rice. However, milling quality including brown rice rate and head rice rate was significantly increased under T3-T5, compared with T2. Protein content was also increased significantly. Three rice varieties under T4 with higher nitrogen fertilizer application had the highest protein content, while protein content under T1-T3 with lower nitrogen application was lowest.In conclusion, T3, T4 and T5 which intergrated agronomic practices can increase grain yield significantly. For grain quality, their effect on eating and cooking quality and appearance quality was not obvious, but can improve the milling quality and protein content significantly.