Effects Of Soil Organic Mater Quantity And Quality On Tillage Systems In Black Soil

There are many theoretic and technical problems about assessment of quality degradation in black soil at present,it is obscure in the cause and mechanism of quality degradation in black soil.This article did research on the amount and quality of organic substance in the black soil under different tillage systems,the result of research supplied theoretic meaning to interpret the degradation mechanism of black soil and discuss the evolvement law of black soil quality,which could provide theoretic support to the fertilization and quality maintenance of black soil.This research selected soils which in some kinds of present tillage systems and the arable slope land under different slope location in Jinlin province including conventional tillage, no-tillage,deep-plough,deep-loose ect.as research object,did research with conventional analysis and modern instrumental analysis.Analyzed the amount and quality property applying elemental analyzer,differential thermal analyzer,infrared-spectrum analyzer,UV-vis analyzer, analyzed the effect of tillage systems on the soil physical properties,humic substance(HS)' s constitutes and structure,made sure that the constitutes and structure of HS under different tillage systems,did pilot study on the structural characteristics of humin(HM) under different tillage systems,provided new information for the research about the HS,HM,soil humic substance chemistry.This article consists of seven chapters,the first chapter is introduction that expatiated the aim and significance of this research,the abroad and domestic situation as well as the technologic courses and innovation about this research,the second chapter is materials and methods,introduced the soil samples and experimental methods,the third to seventh chapter is the analysis and results of this research.The results are as follows:(1) The difference of soil bulk density in 0-40cm soil layer under each tillage measures is little(between 1.3 to 1.4 );deep-loose and conventional tillage are benefit for soil moisture conversation.(2) The soil organic carbon in 0-20cm soil layer under no-tillage measure is higher than other tillage measures,and the absolute and relative amounts of each HS constitutes are similar, which resulted in soil property become identity,and in favor of the conservation and improvement of soil fertility;The increasing extent of soil organic carbon in 0-20cm soil layer under deep-loose is higher than other tillage measures,and deep-loose led to its molecular structure of humic substance(HA) simpler,its molecular structure of fulvic substance(FA) more complicated.(3) Under no-tillage measure,the condensation degree of HA and FA is high, oxygenation degree is low,and their molecular structure is more complicated,and aromaticity is higher,but the HA and FA under conventional tillage have stronger aliphaticity and weaker aromaticity.The analysis on the structure of HA under these tillage measures showed the humicity of HA in black soil is higher,became mature.Comparing different tillage measures,under no-tillage measure molecular structure of HMc is relative complicated,aromaticity is higher,molecular structure of HMc is simpler.Under autumn-plough measure,the aliphaticity of HMi is strongest,the aromaticity is weak,but under conventional tillage,these properties of HMi are converse,and the aliphaticity of HMc is strong, molecular structure is simple.(4) The content of soil total carbon presented the trend that increased by degrees collectively,the molecular structrue of HE in each slope location under transverse slope with ridge-tillage is similar in some extent,But in 20-40cm soil layer,the molecular structrue of HE became complex with decresing of slope location..The results of amount of each HS constitutes in terrace is similar to transverse slope with ridge-tillage,we consider that there is a rule between slope location' s and amount of each HS constitutes' s change.