Effects Of Straw Composting On Growth,Soil Nutrients And Water Environment Of Eggplant

In order to solve the problem of unreasonable disposal of tomato straw and agricultural non-point source pollution,this paper discussed the value of returning tomato straw to field by comparing the effect of returning tomato straw and corn straw.The purpose of the experiment is to study the changes of physical and chemical properties of corn straw and tomato straw in the process of composting.After composting,the two kinds of straw were laid and returned to the field.The effects of corn straw and tomato straw returning in different thickness or mixed with sawdust and mushroom residue on the agronomic characteristics,yield and yield of egg plant were compared Soil nutrient content and farmland water pollution.In the field returning experiment,there were three kinds of returning thickness,1cm,3cm and 6cm respectively;Five treatments were set under each returning thickness,which were T1(corn straw),T2(tomato straw),T3(Plant Mix),T4(bacteria Mix)and CK(control).Plant mix was the mixture of corn straw,tomato straw and sawdust,and bacteria mix was the mixture of corn straw,tomato straw,sawdust and bacteria residue.There were 3 replicates for each returning thickness and 9 replicates for each treatment.The results show that:(1)The decomposition rate of organic matter reached 46.4%during the composting process.The total nitrogen content increased rapidly,the highest content increased by 0.25%compared with that before composting.The total phosphorus content was always lower than the initial value 30 days before composting,and then increased.The total potassium content was always lower than the initial value during the composting process.However,the decomposition rate of organic matter reached 54.3%,and the total nitrogen content was always lower than the initial value.At the end of composting,the total phosphorus content increased by 0.05%compared with the initial value,and the total potassium content decreased sharply.After 40 days of com posting,the total nitrogen content decreased by 0.19%compared with the initial value.The temperature changes of tomato straw and corn straw in the process of composting showed three stages:heating,high temperature and cooling.(2)In addition to T1 treatment,other treatments could promote the agronomic traits of eggplant to varying degrees under the thickness of 1 cm.Among them,T4 and T3 treatment had the best effect and the most obvious promotion effect.Compared with CK,T3 treatment incre ased fruit length,fruit diameter,fruit number per plant and fruit quality in early stage by 14.5%,14.2%,10%and 16.1%respectively.The results showed that T1 treatment still had no pro moting effect on the whole under the thickness of 3 cm,and T4 and T2 treatments had the best promoting effect.Under the thickness of 6cm returning to field,each treatment had a promoting effect on the agronomic characters of eggplant.Compared with CK treatment,T1 treatme nt increased plant height,trunk height and stem diameter by 8.7%,8.3%and 07%,respectively;0.8%、0.2%、1.7%。(3)Under 1 cm returning thickness,T1 treatment had no significant effect on yield,while T2 treatment had the best effect.Under the thickness of 3 cm,the Eggplant Yield of T2 treatment was the highest,increased by 21.7%compared with CK treatment,followed by T4 treat ment,increased by 18.3%compared with CK treatment,and even T1 treatment had a significant increase,increased by 10.5%compared with CK treatment.The yield of T2 treatment was the highest,reaching 1521kg/667m2,and the yield increase rate was 14.6%under 6cm returning thickness.(4)Under the thickness of 1 cm,except T4 treatment,all treatments promoted the soil nutrient content.T2 treatment had the highest content of available nitrogen,available phosphorus and available potassium,which increased by 20.0%,36.8%and 25.0%compared with CK treatment.The contents of available nitrogen,available phosphorus and available potassium in T2 treatment were still the highest under the thickness of 3 cm,increased by 26.7%,42.1%and 32.5%compared with CK treatment.The results showed that the contents of available nitrogen,a vailable phosphorus and available potassium in T4 treatment were the highest,increased by 40.0%,46.3%and 41.3%respectively compared with CK treatment,followed by T2 treatment,increased by 36.0%,44.2%and 37.5%compared with CK treatment.(5)The results showed that the concentrations of TN and TP in T1 and T2 treatments were higher than those in T3 treatments under the returning thickness of 1cm,3cm and 6cm,and the decreases of TN and TP in T3 treatments were 29.81%,28.6%and 17.22%compared with CK treatments under the returning thickness of 1cm,3cm and 6cm;25%、19.5%、13.52%。In addition,the concentrations of TN and TP in field runoff decreased with the growth of eggplant;The total amount of TN and TP discharged into the river was 6263 T/A;The total amount of TN and TP discharged into the river can be reduced by returning tomato straw to the field,and the total amount of TN and TP discharged into the river is 3552 T/A.