Study On The Quality And Formation Difference Of Rice With Different Nitrogen Use Efficiency Under Organic Cultivatin

Organic agriculture as an environment-friendly agricultural production system is developing and expanding in China.Organic rice production in China has many favorable conditions and larger development space.At present,there are many studies on the quality of rice and formation at home and abroad.However,there are few studies on the quality of organic rice and its formation.This study was conducted in an organic farm in Gaoyou city in 2016.The study used yangjing4227,zhendaol5,nanjing46(with high NUE under organic cultivation,H-type)and huaidao5,suxiangjingl,yinyu2084(with low NUE under organic cultivation,L-type),with three treatment included blank control(CK),organic cultivation(OF)and conventional cultivation(NF).The plant samples were taken every 10 days after the flower,and 6 times were taken.and the sampling time was recorded as T1-T6;the soil was taken the first sample at 10 days after the flower,and the sampling time was recorded as ST1,and then the sample was taken every 20 days,3 times,and the sampling time was recorded as ST2?ST4.Compared different nitrogen use efficiency under OF and NF,which provided theoretical and technical basis for the grain quality control of organic rice.The main results are as follows:1.With the grain filling process,the content of soil organic matter increased and then slightly decreased under OF and NF;the content of soil organic matter in different stages under OF were higher than that under NF.Cultivation methods had little influence on soil total nitrogen content and content of alkaline nitrogen during ST 1?ST2 stage,and had significant influence on alkaline nitrogen during ST3?ST4 stage.2.Nitrogen efficiency and cultivation methods have significant effects on nitrogen content of rice stem,and the cultivation method has very significant effect on nitrogen content of leaves.By compared the nitrogen content in stem,leaf and panicle,it showed the stem nitrogen content at T6 stage in H-type were higher and that in H-type were lower than T1 stage under OF and NF.The leaf and panicle nitrogen content at T6 stage in two types were lower and higher than T1 stage under OF and NF,respectively.3.With the grain filling process advancing,the content of protein in grain basically showed a downward trend,and the rate of decline gradually slowed down.The accumulation of protein showed a gradual upward trend,and followed an"S" curve increase.The accumulation rate of protein in H-type reached the maximum at T3-T4 stage,while that in L-type reached the maximum at T2-T3 stage.The content and accumulation of amylose,amylopectin,total starch all followed an "S" curve increase.At T6 stage,the content and accumulation of amylose starch in Nanjing46 under OF were higher,while other rice varieties were lower than that under NF;the content of amylopectin starch in Yangjing4227,Nangjing46 and Huaidao5 under OF were lower,while other rice varieties were higher than that under NF;the content of total starch in Zhendao15 was contrary with the content of amylopectin starch,whereas a consist trend with the content of amylopectin starch in other rice varieties;the accumulation of amylopectin and total starch in Suxiangjingl under OF were higher,while other rice varieties were lower than that under NF.4.The theoretical yields of all varieties were lower under OF than that under NF.The main reason for the decrease of yield under OF was the decrease of panicle number less than NF.Organic farming significantly reduced the 1000-grain weight of H-type.And the 1000-grain weight of L-type under OF decreased slihgtly.5.Compared with NF,OF could reduce the processing quality of rice,and improve the cooking and eating quality.Different NUE and cultivation methods had no significant influence on appearance quality.RVA profile characteristics under OF by and large were better than that under NF.The setback and peak time value of all varieties under OF were lower than that under NF.6.Organic farming significantly increased the starch granule average size and the proportion of large granules(diameter>7?m)and reduced the proportion of small granules(diameter<7?m).Different NUE and cultivation methods had no significant effect on the crystal pattern.Compared with NF,the starch crystallinity of yangjing4227,huaidao5 and yinyu2084 under OF were higher 12.75%,9.11%and 6.91%,respectively.And zhendao15,nanjing46 and suxiangjingl under OF were lower 3.70%,6.74%and 6.91%than that under NF,respectively.Under OF,the peak temperature and peak index of H-type were lower 6.58%and 8.03%than that under NF,respectively.And peak temperature and peak index of L-type were higher 6.58%and 8.03%than that under NF,respectively.