Effects Of Chinese Milk Vent Returning To The Field Coupled With Rice-fish Symbiosis On Soil Nutrients And Population Growth Characteristics Of Double Cropping Rice

Chinese milk vent returning to the field and rice-fish symbiosis are two effective methods of soil fertility.In order to explore the effect of Chinese milk vent returning to the field coupled with rice-fish symbiosis on rice nutrients and population growth characteristics,provide scientific basis for efficient and high-quality rice production.In this experiment,four treatments including conventional rice planting(CK)as a control,Chinese milk vent returning to the field(ZD),rice-fish symbiosis(YD),Chinese milk vent returning to the field coupled with rice-fish symbiosis(ZY)were set up,The measurement,analysis and comparison of soil physical properties,nutrients(total nutrients and available nutrients),rice population growth characteristics,rice yield and yield composition index in each treatment were conducted to explore the law of soil fertility,population growth characteristics of rice,reasons for rice production of"Chinese milk vent returning to the field coupled with rice-fish symbiosis",and research on the relationship between the Chinese milk vent returning to the field and rice-fish symbiosis.The result is as follows:1)Compared with CK treatment,YD,ZD and ZY treatment can effectively improve the soil structure(density,total porosity),and the effect of ZY treatment is more significant than that of YD and ZD treatment.After late rice in 2019,the soil density of the ZY treatment was reduced by 9.32%compared with the CK treatment,and the total soil porosity increased by 17.46%;2)Compared with the CK treatment,the soil p H in the YD treatment showed a decreasing trend,the soil p H in the ZD treatment showed an increasing trend,and,Chinese milk vent returning to the field could effectively slow down the decline in the soil p H caused by the fish farming in the paddy field.After the late rice in 2019,the law of soil p H of each treatment was ZD>CK>ZY>YD,and the p H of CK teeatment is 5.90,compared with the CK treatment,YD processing decreased by 0.09 units,ZD processing increased by 0.04 units,and ZY processing decreased by 0.06 units;3)YD,ZD,and ZY treatments can effectively increase the soil fertility of double-season rice and increase the content of soil organic matter,total nitrogen,alkaline nitrogen nitrogen,available phosphorus,and available potassium,and the treatment effect of ZY treatment is better than that of YD and ZD treatment,but the effect of ZD treatment on soil total phosphorus and total potassium is not obvious.After late rice in 2019,the soil organic matter,total nitrogen,total phosphorus,total potassium,total potassium,alkaline nitrogen,available phosphorus,and available potassium increased by 13.52%,24.14%,22.58%,5.87%,3.79%,13.18%and 4.91%compared with CK treatment;4)YD,ZD,and ZY treatments can effectively improve the agronomic performance of double-season rice,increase the rate and efficiency of rice material accumulation and transport,and the effect of ZY treatment is optimal.In the double-season rice in 2019,the leaf area index of rice at the heading stage of ZY treatment increased by 11.33%and 50.26%respectively,and the photosynthetic potential of ZY treatment from tillering stage to heading stage compared CK treatment increased by 12.30%to 28.96%and 24.00%to 48.46%respectively,the net assimilation rate of ZY treatment from ear differentiation stage to heading stage compared CK treatment increased by 12.84%and 23.91%respectively;5)YD,ZD and ZY treatment can effectively improve the above-ground biomass of double-season rice.The highest above-ground biomass of double-season rice was ZY treatment in 2019 of 76.39g and 80.39g.Early rice ZY treatment increased 11.22%,8.81%and 0.90%compared with CK,YD and ZD treatment,late rice ZY treatment increased by14.34%,5.42%and 5.78%compared with CK,YD and ZD treatment.ZY treatment promotes the transfer of material to the ear while increasing above-ground biomass.The double-season rice receipt index of each treatment in 2019 is the highest with ZY treatment,respectively 0.58 and 0.59;6)The yield of rice in the three seasons of ZY treatment is 6.29t/hm~2,6.68t/hm~2,7.15t/hm~2,which the increase in yield is 9.51%to 17.99%,2.23%to 11.72%,0.44%to14.95%compared with CK,YD and ZD treatment,The number of grains per ear of rice is the main factor affecting the formation of rice yield;7)In summary,YD,ZD,and ZY treatment can effectively improve soil physical properties and increase soil nutrient content of double-season rice,and ZY treatments are more effective than YD and ZD treatment;YD,ZD,and ZY treatment can effectively improve and optimize the population growth characteristics of double-season rice and promote the increase of double-season rice yield,of which ZY treatment is better than YD and ZD treatment.