Effects Of Straw Return Field And Nitrogen Application On Soil Nutrients, Microorganism And Rice Yield

At present,the soil quality of arable land in China is declining,one of the reason is that it relies too much on fertilizer and ignores the application of organic manure.At the same time,if the straw resources are not fully utilized,it may cause serious pollution to the agricultural environment.In this paper,pot experiment was used to study the effect of different nitrogen application on soil effective nutrient status,rice growth and yield under the condition of total straw return,and the effects of different amount of nitrogen fertilizer on soil physical and chemical properties,microorganism and yield were analyzed.Using pot experiment method,10kg of soil per basin,straw return field quantity is 20g/basin,at the same time with different amount of nitrogenous fertilizer,two consecutive years(2016 and 2017)for simulation test.2016 trial altogether set up 8 treatment,respectively:straw return field,urea application amount is 0(JNO),straw return field,urea application quantity is 0.87g/basin(JN6),1.15g/Basin(JN8),1.45g/Basin(JN10),1.74g/Basin(JN12),2.02g/Basin(JN14),2.33g/Basin(JN16),straw is not returned to the field,only the urea 1.45g/Basin as a control(corresponding to the application of nitrogen 150kg/ha)(N10).The 2017 trial altogether had 7 treatment,the original soil(treatment 0),the Straw return field Urea application amount is 0(JNO),the Straw return field,1.43g/Basin(J:N10),2.00g/Basin(JN14),2.58g/Basin(JN18),3.58g/Basin(JN25);Only the urea 1.43g/basin was used as control(corresponding to the field nitrogen 150kg/ha)(N10).Each processing 3 times repeats,randomly sorted.The plant height,tiller number,SPAD value(relative content of chlorophyll),thousand grain weight,grain weight,soil effective nitrogen,available phosphorus,instant potassium,organic carbon,carbon/nitrogen ratio,pH and conductivity of rice were determined.The significant consequences indicated as following:(1)The Effects of straw return field and nitrogen fertilizer application on soil nutrient content showed that:the soil ph value was increased and the soil conductivity was increased with the application of nitrogen fertilizer in the field of straw.The content of available phosphorus in soil decreased with the increase of rice growth cycle,but there was no significant effect of different amount of nitrogen fertilizer applied in straw returning to field.The content of available potassium in soil was increased by applying different amount of nitrogen fertilizer.After tillering period,the content of available k in the soil was significantly higher than that of N10 and JNO in the field of 1.45g/Basin chemical nitrogen Treatment(JN10).The content of ammonium nitrogen in soil was decreased by applying different amount of nitrogen fertilizer in straw returning field.The content of ammonium nitrogen in soil was significantly lower than that of straw(JNO)and only nitrogenous fertilizer(NO),and the nitrogen content of soil was decreased by applying different amount of nitrogenous fertilizer in straw returning field.(2)The Effects of straw return field and application of nitrogen fertilizer on rice growth and yield the results showed that the application of nitrogen fertilizer in the field of straw also promoted the growth and development of rice and increased rice yield.The plant height of straw combined with 1.45g/Basin chemical nitrogenous Fertilizer Treatment(JN10)was significantly higher than that of single application of chemical nitrogen fertilizer(N10);At the same time,the tiller number of rice was significantly higher than that of single straw treatment(JNO),and 2.58g/Basin(JN18),3.58g/The weight of stem grains in basin(JN25)nitrogen treatment was significantly higher than that of N10.(3)The Effects of straw return field and nitrogenous fertilizer application on soil microbial diversity:In the rice seedling stage,the microbial richness index was higher than that of JN6 and JN10 and the difference was significant in the bacterial community structure,which showed that the straw returning to the field had no significant influence on the microbial community;The Venn diagram shows that the The growth of the main microbial community is beneficial to the straw returning to the field,regardless of the application of nitrogenous fertilizer.