| Film technology of double Ridge and furrow sowing has become semi-arid subhumid dry-farming on the loess plateau is a large area used for crops planting,which has covered anti-steam,the advantages of ditch sowing,insulation of rainwater.Corn straw is rich in organic matter,which can be used as input to the soil to help the growth of crops.But because the water temperature in the loess plateau is not desirable and scarce rainfall,decaying corn stalks needed for a long time,so we double ditch plastic film technology and combine the strengths of both of straw,found a way to improve soil fertility and increase crop yields in cropping patterns.However,whether the soil quality will be affected by the planting pattern,the increase of soil quality and crop yield can not be based on the soil quality.Soil aggregates,pH value and bulk density are important indicators to evaluate soil quality.The experiment was conducted in Yuzhong,Tongwei,Huining countries of Gansu province 2015.Including four treatment(1)no straw incorporation + no plastic film mulch(CK);(2)no straw incorporation + plastic film mulch(M);(3)straw incorporation + no plastic film mulch(S);(4)straw incorporation + plastic film mulch(SM);three replications and random arrangement.In July 2015 and harvest samples determined pH,total nitrogen,nitrogen mineralization,soil aggregate water stability,MWD,soil moisture,microbial carbon and nitrogen,organic carbon,bulk density and biomass of corn.Main results as follows:(1)The yield increasing effect of plastic film mulching on Grain Yield and root biomass was significant.The experiment will be compared with non mulching treatment on Grain Yield and root biomass yield were 83% and 34%,Yuzhong experimental yield rate were 140%-38%.Straw returning had no significant influence on it.(2)Straw significantly can significantly affect the total nitrogen content,less straw treatment increased 18-30%;can significantly affect the organic carbon content,the rate of increase of 12-40%;can significantly affect the microbial biomass carbon and nitrogen content increased,respectively 42-117%,16-102%;can significantly affect the soil bulk density decreased to 4-9%.(3)Plastic film mulching can significantly affect the content of nitrate nitrogen,compared with non mulching treatment increased the amplitude of 73-325%;can significantly affect soil pH,reduce the rate of 0.19-0.35;can significantly affect soil bulk density,increase the amplitude of 6-7%.There was a strong correlation between pH value and nitrate nitrogen content.(4)Straw returned to soil had a significant effect on the content of organic carbon.Straw returning had a tendency to increase the content of organic carbon.The contents of organic carbon,total nitrogen and microbial biomass carbon and nitrogen were increased by 12-40%.Straw mulching could significantly affect soil bulk density,straw treatment was less than 4-9% without straw treatment,mulching treatment increased by 6-7%.Through the above experiments we found that straw mulching and plastic film mulching could significantly increase the proportion of mm(>0.25),the soil aggregates increased with the increasing of good soil porosity,loose soil,tillage,soil and fertilizer supply coordination stability,strong performance,Straw mulching and plastic film mulching could significantly increase the proportion of soil aggregates,which might be related to the increase of root biomass and microbial activity;Plastic film mulching significantly reduced pH,so that the soil was weak acid may undermine the quality of the soil,affecting the growth and development of microorganisms and farmland crops,pH decreased with the concentration of nitrate nitrogen in the soil;Plastic film mulching increased soil bulk density,soil compactness,and could directly or indirectly affect growth and development.Straw mulching and tillage affects soil quality,in farming farmland mulching can carry out a year,is conducive to the recovery of soil quality. |
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