Effect Of Corn Stover Incorporation With Different Ways And Years On Soil Fertility And Structure Of Organic Matter In Aggregates

In recent years,the treatment of crop straw is a huge problem in our country.Experts and scholars express their own views on how to effectively use crop straw.A large number of studies have shown that straw contains a lot of nutrients,which can not only improve soil fertility,but also improve soil quality,and all of which are of great significance for water conservation and fertilizer conservation.At present,there are few studies about the influence of different ways of returning straw on the soil and the organic matter in aggregates.Based on this reason,a cultivation experiment was conducted to study the changes of soil organic carbon and humus composition under different methods of corn stover application,Field experiment was carried out to study change features of soil humus composition and soil aggregate humus composition and structure with years of growth.This study provides a theoretical basis for effective utilization of crop straw,soil carbon sequestration and soil fertility.Results showed:(1)The content of organic carbon in the surface layer and subsurface layer of cultivated soil showed the most obvious trend of increase in the organic carbon content of corn stover deep incorporation(CSDI).The surface layer and subsurface layer increased by 24.2% and 42.6%,respectively,and the subsurface layer was significantly more than the surface layer.(2)Corn stover application can increase WSS organic carbon content,and CSDI increases most significantly.The content of HA organic carbon in CSDI increased the most,which increased by 28.6%.Shallow straw HA also had the least increase in organic carbon,which increase by 3.14%.The CSDI can also increase the PQ value of soil surface,and the increase trend is more significant than the subsurface layer.(3)The CSDI also increased the soil moisture content,and the CSDI(2014)increased significantly,and then decreased year by year,and the subsurface layer was more prominent than the surface layer;The CSDI also has a good effect on the soil water retention improvement,and can promote the increase of soil porosity and promote the growth of crops.(4)After CSDI,the contents of available phosp-horus,and available potassium were all increased.Among them,CSDI(2014)was the most prominent and the surface was significantly than the subsurface.(5)the most prominent and the surface was significantly than the subsurface.(6)After CSDI,the organic carbon content in the surface soil and the subsurface soil showed an increasing trend,and the CSDI(2014)showed the most obvious and then decreased year by year;The organic carbon content of the aggregates also increase on CSDI(2014),and then it goes down year by year,and two large aggregates increased significantly.(7)After CSDI,the quality of humus was improved,HA and HM ratios increased,and the proportion of FA has declined,the organic carbon content of HA was not significant.With the days going on,the organic carbon content of HA showed an upward trend,while FA and HM showed a downward trend.(8)After CSDI,the condensation degree,oxidation degree and thermal stability of HA and aggregates HA in the soil was reduced,the aliphatic carbon/aromatic carbon and aliphatic carbon/carboxyl carbon content increased,the CSDI(2014)is most significant,and two large aggregates are significantly than two small aggregates.With the days going on,HA displayed an increasing trend in condensation and oxidation degree and became lower in aliphaticity,higher in aromaticity,and more complicated in structure.(9)The CSDI(2014)increases the content of crop yield by 6.25%,with the days going on,the minimum output is 2%,and tend to be lower.