Effects Of Straw Returning Manner Coupled With Duck Raising In Paddy Field On Rice Growth And Ecological Environment

The biomass of rice straw is huge.Improving the utilization rate of straw,reducing the air pollution caused by straw incineration and alleviating the aggravation of greenhouse effect,returning straw to the field is one of the effective solutions.Duck raising in paddy field enriches the ecosystem and has high social,ecological and economic benefits.Therefore,exploring the coupling of straw returning to the field and duck raising in paddy field of the growth and development of rice and environment has great significance.Based on the summary of previous studies on rice duck co breeding technology,a two factor experiment was designed,F1 was duck raising in rice field and no duck raising in rice field,and F2 was straw returning,straw carbonization returning and straw non returning.That is,straw carbonization returning coupled with duck raising in rice field(RBD),straw carbonization returning coupled with no duck raising in rice field(RBN)Straw crushing coupled with rice field duck(RSD),straw crushing coupled with rice field without duck(RSN),rice monoculture(RNN)and rice field duck(RND)were studied to analyze the effects of straw returning coupled with rice field duck on soil,rice growth and development characteristics,quality,diseases,pests and weeds to explore the influencing factors and mechanism of yield,composition and quality.Then to explore the formation law of the environment and ecological environment of duck breeding in rice field coupled with the way of straw returning to the field.The main results are as follows:1)This study made it clear that raising ducks in paddy field could improve the leaf area index,leaf biomass,population growth rate and photosynthetic potential of rice at maturity.Straw returning and straw carbonization returning can also improve the leaf area index and leaf biomass of rice at maturity,but the population growth rate of straw returning decreased and the population growth rate of straw carbonization returning increased.Therefore,the rice yield showed that the yield of duck raising in rice field increased,but under the condition of straw carbonization,the yield of duck raising rice in rice field decreased,and the yield of straw carbonization and direct straw decreased.2)The rice quality of late rice is better than that of early rice.Straw returning coupled with duck raising in rice field can improve the rice quality of early rice better than that of late rice.Straw returning and straw carbonization returning can improve rice quality.Raising ducks in paddy field improved the milling quality,appearance quality and nutritional quality,but the gelatinization temperature increased.3)The appearance and morphology of straw carbonization and straw returning were improved.The lodging resistance of straw carbonization returning was higher than that of straw direct returning.Raising ducks in rice field improves the internode length of section 1and 2,the dry weight and internode fullness of section 2,has closely arranged epidermis and vascular bundles,significantly reduces the height of rice gravity center,improves the wall thickness of rice internodes,further improves the bending force and bending moment of each internode,and improves the lodging resistance.Compared with rice single planting,the lodging resistance of each treatment was improved.4)Duck raising in rice field can effectively control diseases,pests and weeds in rice field.Duck raising in rice field reduces the species richness of weeds,but improves Simpon index,Shannon Wiener index and Pielou index.In the later stage of rice growth,the control effects of weed density and dry weight reached 84.53% and 72.93% in 2020 and 2021,69.78% and 69.76%,which can significantly reduce the rice field index,the incidence of rice planthopper,Chilo suppressalis and rice leaf roller,and reduce the incidence of sheath blight and rice blast.Straw returning to the field increases the occurrence of rice diseases,weeds and pests to a certain extent.Straw carbonization reduced the occurrence of rice field diseases.5)The pH value of ducks raised in paddy field showed a downward trend,and the content of soil available nutrients increased.The pH value of straw returning and straw carbonization returning soil increased,the content of soil organic matter increased as a whole,and the content of available potassium increased,but the content of alkali hydrolyzable nitrogen decreased in some periods.Straw degradation showed an S-shaped curve.60 days before straw returning to the field,the straw degradation rate of ducks raised in rice field was lower than that of ducks not raised in rice field,but after 60 days,the straw degradation rate of ducks raised in rice field was higher than that of ducks not raised in rice field.In conclusion,the coupling of straw returning to the field and duck raising in rice field has a certain impact on rice growth and development,rice quality,stem breaking resistance,soil nutrients and field diseases,pests and weeds.This study can provide a theoretical basis for straw returning to the field and duck raising in rice field.