Effect Of Straw Returning On Growth And Yield Of Soda Saline-alkali Rice

In order to explore the effects of straw returning on the growth and development of rice in soda saline soil,rice yield formation and nitrogen use efficiency.This experiment was conducted in 2017~2018 in Sheli Town,Da'an City,Jilin Province.The experiment was conducted with Changbai 9 as the test material,and no straw returning(S0),straw 40%returning to the field(S1),straw 60%returning to the field(S2),straw 80%returning to the field(S3)and straw total returning to the field(S4),a total of 5 straw returning levels,of which no straw returning field(S0)as control,the total amount of straw returning is calculated from the ratio of grain to grass(7.0 t/hm~2).The growth traits,photosynthetic characteristics,yield formation and nitrogen utilization of rice were measured.In order to determine the effect of straw returning on the growth and yield formation of soda saline soil.The results of this pilot study are as follows:1.In terms of stem stalk dynamics,the number of rice tillers treated with S3 was the highest in both years.In 2017,within 28 to 42 days after rice regreening,the highest peaks were obtained in each treatment.The highest number of tillers in S3 treatment was higher than other treatments.The highest number of tillers in rice treated with straw returning was higher than the control 11.61%~51.39%.In 2018,within 21 to 35 days after rice greening,the number of tillers in S3 treatment was higher than other treatments,and each treatment reached the highest peak of tillering.The highest number of tillers in rice treated with straw returned to field was higher than that of control 2.25%~34.83%.2.In terms of photosynthetic characteristics of rice,the leaf area index and net photosynthetic rate of rice treated with S3 were the highest in the two years.In the two-year experiment,the leaf area index of each straw treated was significantly higher than that of the control.The two-year increase was 20.20%~54.19%(2017)and 19.73%~52.02%(2018).The net photosynthetic rate of all treatments reached the peak at 20 days after rice full heading,and the net photosynthetic rate of straw treatment was 8.97%~14.60%(2017)and 2.90%~13.98%(2018),respectively.3.In In terms of dry matter accumulation,the total dry matter accumulation of straw treated in the two years was significantly higher than that of the control,and all of them were the best in S3 treatment.With the increase of straw returning,the total dry matter accumulation of rice increased first and then decreased.In the mature stage of 2017,S1,S2,S3 and S4 compared with the control increased by 14.23%,28.83%,35.41%and 16.51%,respectively;in the maturity of 2018,S1,S2,S3 and S4 compared with the control increased by 20.04%,25.84%,53.80%and 45.36%,respectively.4.In terms of yield and yield components,the two-year trial performed best with S3treatment.The actual yield of rice increased with the increase of straw returning,which showed a trend of increasing first and then decreasing.In 2017,the actual yield of straw processing in each field was compared with that of the control,which was S3>S4>S1>S2>S0.The yield of the straw returning treatment was significantly higher than that of the control.The best performance was obtained in S3,and the yield reached 6.48 t/hm~2.The actual yield of the treatment in the straw returning field in 2018 was S3>S4>S1>S2>S0.The yield of straw returning treatment was significantly higher than that of the control.The best performance was obtained in S3,and the yield reached 7.03 t/hm~2.With the increase of straw amount,the effective panicle number,kernel number and seed setting rate per unit area of soda saline soil were increased.Both of them showed the trend of increasing first and then decreasing,and all of them showed the best performance in S3 treatment,but the effect of straw returning on rice 1000-grain weight was not significant,and the difference between treatments in two years did not reach significant.5.In terms of nitrogen utilization rate,the nitrogen partial productivity,nitrogen agronomic utilization rate,nitrogen fertilizer absorption and utilization rate and nitrogen accumulation of straw treatment in 2017 were higher than the control;the nitrogen fertilizer partial productivity and nitrogen fertilizer agronomic utilization rate of S3 treatment compared with other straw returning treatment were significant increased by 16.54%~46.28%and 17.32%~69.28%,the nitrogen accumulation and nitrogen uptake utilization rate of S4 treatment were the best;in 2018the nitrogen fertilizer partial productivity,nitrogen fertilizer agronomic utilization rate,the nitrogen uptake utilization rate and nitrogen accumulation of straw returning treatments were higher than the control;the nitrogen accumulation and nitrogen uptake and utilization rate of S3treatment were the best,and the nitrogen fertilizer partial productivity and nitrogen fertilizer agronomic utilization rate compared with other straw returning treatments were significantly increased by 16.54%~18.81%and 17.32%~20.97%.In summary,straw returning increased the tillering of rice in soda saline soil,improved rice leaf area index and net photosynthetic rate,increased the production capacity of rice photosynthetic materials,thereby increased the dry matter accumulation of rice,enhanced the absorption and utilization of nutrients in rice and improved the nitrogen use efficiency of rice,increased the number of effective panicles per unit area,the number of grains per panicle and the seed setting rate of rice of rice in soda saline-alkali land,improved rice yield.When the amount of returning to the field was 80%,the returning of straw to the field can significantly promote the growth and yield formation of rice in soda saline-alkali land.