Effects Of Straw Return And Food Feeding On Water Quality In Rice Crawfish System

Rice-crawfish system technology is based on rice paddy field conditions,make full use of rice paddies stereo space,light,heat,water and biological resources efficient paddy planting and raising mode of composite based on Rice-crawfish ecological system,the test research of rice shrimp produced influence on water quality.In order to improve the physical and chemical properties of water,improve water management measures to provide a scientific basis by optimizing the nitrogen and phosphorus fertilizer application.This experiment were used middle-season rice Thai 390 and the original crawfish as material in 2015 and 2016 in Houhu of qianjiang city,Hubei province.Setting straw return with no food(SNF),straw return with food(SF),straw counters-field with no food(NSNF),straw returnwith food(NSF)under two modes of the rice crawfish(RC)and rice monoculture(RM),5 treatments,3 replications under the condition of the field.Straw returning also runs and the whole amount to throw food intake according to the shrimp to hurl food weight of 3%-5%.The results of the study are as follows:(1)Through the study of the DO showed that,inwinter bubble period,compared with the water inlet,the DO content of straw counters-field was obviously higher than that of inlet,higher than that of straw return.Under the same straw return,DO of rice was obviously higher than that of rice crawfish system.In rice growth period,theeffect of straw return on DO in rice monoculture was far more than the influence of rice crawfish system(2)Based on the research of the ammonium nitrogen showed that the ammonium nitrogen content of surface water treatment compared with the water inlet,the ammonium nitrogen of content water inlet was higher than the treatment,ammonium nitrogen content was decreasing from the inlet to the field.Surface water treatment were higher than in the ditch water in tillering stage,long spike stage ditch water treatment was higher than the surface water.In the growth period of rice,straw return significantly higher than that of straw counters-field under the same straw processing,food feeding of ammonium nitrogen content above no food feeding of ammonium nitrogen content.Straw return andfood feeding can significantly improve the content of ammonium nitrogen.(3)Through the study of nitrate nitrogen showed that the nitrate nitrogen content of surface water treatment compared with the inlet,water inlet was higher than the inlet,the nitrate nitrogen content from the inlet to field was increasing.In rice growth period,the content of nitrate nitrogen in surface water and the ditch water straw return was higher than that of straw counters-field,it showed that straw return can significantly improve the content of nitrate nitrogen.(4)Through the study of TN showed that in the early winter bubble,each dealing with TN content was on the decline,TN content from the inlet to the field was to reduce,straw counters-field was higher than the straw return;Late winter bubble,the TN content of every processing was on the decline,The TN content from the inlet to the field was to reduce,straw return was higher than that of straw counters-field.TN in rice tillering and long ear stage,from the inlet to the surface content was decreasing.From the point of the whole growth period,the RM-SNF was the highest levels in surface water;The RC-NSF was the highest content of ditch water.Straw return could be significantly increase rice monoculture.(5)Through the study of TN showed that in winter bubble period,each process was on the decline,the inlet of TP content was on the rise.the TP content from the inlet to rice paddies was decreasing in growth period.Straw return had a significant increase in TP concentration.The absorption and loss due to rice,TP content in basic keep low concentration,there was no significant difference between the groups in rice growth period.The solid phase,the straw under the same processing,food feeding could increase the content of TP.(6)Straw returned did not significantly increase rice yield.At the same time rice crawfish and rice monoculture production difference were not obvious.,food feeding could significantly improve the yield of rice under the same straw processing...