The Effect Of Mulching Materials On Potato And The Benefit Analysis In Potato-Cotton Continuous Cropping Mode In Cotton Field Of Northern Jiangxi

Northern Jiangxi is one of the production bases of high-quality cotton.There is largearea winter fallow cotton field which has not been fully utilized all the year round,which leads to the waste of precious land and natural resources.In order to improve the resources utilization and the soil ecological environment,increase the crop yield,multiple cropping index and annual land benefit of,promote the agricultural efficiency and farmers’ income,and stabilize the cotton production,this study took potatoes’ becoming a staple food as an opportunity,carried out the research on the efficient "potato-cotton" planting mode,and planted potatoes by using the two ways comprising black film plus straw mulching and black film mulching in the winter fallow cotton field.The experiment set up 5 teatments,including Treatment A(CK): winter fallow + Gan Mian18,treatment B: Zhongshu5(black film mulching)+ Gan Mian18,treatment C: Zhongshu5(black film + straw mulching)+Gan Mian18,treatment D: Holland15(black film mulching)+ Gan Mian18,treatment E:Holland15(black film + straw mulching)+ Gan Mian18.It aims at finding out the effects of the two mulching materials on potato agronomic characters,commercial characters and yield,exploring the changes and rules of soil nutrients before and after potato planting,clarifying the effect of potato planting on the agronomic,yield and quality characters of cotton.This paper expounded the economic benefit,social benefit and ecological benefit of potato-cotton continuous cropping in order to screen the planting models with highest comprehensive benefit.The main research results are as follows:1.Under the same mulching material,Zhongshu 5 had better growth advantage,faster material accumulation and higher yield than Holland 15.The average soil temperature,average relative humidity,,average SPAD value,dry potato weight per plant on the 116 th day and dry weight ratio between aboveup ground and belowground part of Zhong Shu 5were 0.08 ℃,4.03%,1.4%,14.66%,46.73%,14.34% higher than that of Holland 15,respectively.The emergence rate and incidence rate were 1.2%,11.94% lower than that of Holland 15,respectively.The number and weight of big potatoes per plant,total potato weight of Zhongshu 5 were higher than those of Holland 15,and Zhongshu 5 had higher starch concentration and lower sucrose,glucose and fructose concentration;the fastest accumulation rate,average accumulation rate and theoretical maximum value of dry weight and total dry weight of Zhongshu 5 were higher than those of Holland 15;the final yield of Zhongshu 5 was 52.53% higher than Holland 15.2.Under the same potato varieties,black film + straw mulching is more conducive to potato growth than black film mulching.The temperature control effect of black film + rice straw mulching was better than that of black film mulching alone.Compared with black film mulching,black film + rice straw mulching increased soil temperature by 0.69 ℃,decreased daily range by 0.16 ℃,and the relative humidity in the field was small,with an average relative humidity of 0.72%.Compared with black film mulching,black film + rice straw mulching increased potato seedling rate by 3.74%,plant height by 11.13%,dry weight of tuber by 19.13% and big potato by 26.91%,total potato weight per plant by19.04%.On the 116 th day,the ratio of dry weight between aboveup ground and underground part increased by 15.41%,and the yield increased by 12.14%.In addition,the rate of green head decreased by 36.8%,and the incidence rate decreased by 43.3%.The fastest accumulation rate,average accumulation rate and theoretical maximum value of dry weight and total dry weight per plant were black film + straw mulching,which were32.53%,24.85%,24.98%和 22.04%,22.26%,30.23% higher.In the early stage of black film + rice straw mulching,more soluble sugar was accumulated in tubers,and more soluble sugar was used for starch synthesis.3.The interaction of mulching material and potato can improve the soil environment,and soil nutrients,and promote the growth and yield of cotton.After planting potato,the p H decreased and the alkalinity weakened,and the total nitrogen,total phosphorus,available phosphorus,available potassium,organic matter,available boron,available zinc and exchangeable manganese were all significantly higher than those of the winter fallow plot without planting potato;After planting potato,cotton seedling,flowering and catkins emerged early,and the first branch node,stem diameter,number of branches and chlorophyll SPAD value were significantly higher than that of winter fallow plot.In addition,the number of big bolls per plant,bolls per plant,lint percentage,seed cotton yield and lint yield were significantly higher than that of winter fallow plot.4.The yield and net income of "potato + cotton" mode is higher than "winter fallow +cotton" mode.Black film + straw mulching is higher than black film mulching,and "Zhongshu 5 + cotton" continuous cropping is better than "Holland 15 + cotton" continuous cropping.The order of comprehensive benefit index was treatment C(0.9988),treatment B(0.9171),treatment E(0.8219),treatment D(0.7481)and treatment A(0.50720),which indicated that the economic,ecological,social and comprehensive benefits of the continuous cropping of Zhongshu 5 black film + straw mulching material and cotton multiple cropping were the best,which was a more suitable and efficient planting mode in the Northern Jiangxi cotton area.