The Effect Of Long-term Fertilization On Composition And Structure Of Humus In Black Soil

Humus is an important composition of soil organic matter,the number and quality of humus is an important index of soil fertility.The effects on long-term different fertilization on the combined forms and numbers and structure of humus of black soil in passed sixteen years were studied on the basis of long-term located experiment.This study trying to reveals the influence law of different fertilization on black soil humus and put forward a method of fertilization to improve soil organic matter.So that we can cope with the present situation of the decline of organic matter and black soil fertility,and can also find provide the basis for the rational application of ensure the high quality and high yield of crop.Based on the data analysis,the result of the study indicated that:1.The contents of organic carbon in three fertilizer treatments increased by 5.8?13.1%per year on average than CK treatment,and the contents of organic carbon in heavy fraction increased by 5.8-11.3%per year on average than CK treatment under the long-term fertilization.The contents of the loosely combined humus was richest,the contents of the steady combined humus was moderate,the contents of the tightly combined humus was the smallest in all fertilizer treatments,and the contents of loosely combined humus in manure treatment was richer than chemical treatment.The contents of loosely combined humus in fertilizer treatments increased by 8.8?28.5%,the contents of steady combined humus increased by 10.1?45.7%,the ratio of loosely to tightly combined humus increased by 6?74.4%.The growth of manure treatment and manure+chemical treatment were higher than chemical treatment.The growth of three fertilizer treatments are increasing year by year.2.The quantity of organo-mineral complexation in fertilizer treatments were increased by 6?10.8%compared with CK treatment on average,the degree of organo-mineral complex in fertilizer treatments were increased by 1?1.9%compared with CK,and the growth of manure+chemical treatment were higher than other treatments.The quantity of organo-mineral complexation and the degree of organo-mineral complex are increasing along with the year of fertilizer increased.The additional quantity of organo-mineral complexation of the manure+chemical treatment was higher than manure treatment and the additional degree of organo-mineral complex is lower than manure treatment,shows that the regulation of organic inorganic compound of soil with manure+chemical treatment is better than manure treatment.3.The contents of organic carbon in WSS under three fertilizer treatments increased by 7-25.3%per year on average than CK treatment,the contents of organic carbon in HE under three fertilizer treatments inceased by 12.6-35.9%,The contents of organic carbon in HA under three fertilizer treatments increased by 19.6?46.8%,The contents of organic carbon in FA under three fertilizer treatments increased by 3.1?15.4%,The contents of organic carbon in HM under three fertilizer treatments increased by 4.7?11.1%,these growth of manure+chemical treatment were higher than manure treatment and chemical treatment.The contents of organic carbon in WSS and FA under all of treatments were tending to decline with the year of fertilizer increased.The contents of organic carbon in HE,HA and HM under manure treatment and manure+chemical treatment were tending to increase with the year of fertilizer increased.The contents of organic carbon in HM were tending to increase and the contents of organic carbon in HE and HA were tending to decline or remain flat under chemical treatment and ck treatment.The ratio of HA to FA under three fertilizer treatments increased by 9.1%?28.5%per year on average than CK treatment and the growth are increasing year by year.4.We found that the Alog K and E4/E6 of WSS in fertilizer treatments were increased and still in reducing year by year by comparing the optical properties of four treatments.The Llog K and E4/E6 of HE,HA and FA were tending to increased under fertilizer measures,but also tending to decline year by year.Fertilizing make the structure of WSS becoming complexd and still becoming more complex year by year.Fertilizing make the structure of the other components of soil humus simplified,but long-time farming will make the structure of soil humus aging.5.The structure of HA after long-term fertilizations and farming is complex,removing this complex structure there contains a few aromatic hydrocarbon with simple structure.Fertilizations make the structure of HA more youthful and the degree of condensation and aromaticity are more lower than CK treatment,manure+chemical treatment is most obvious among these effects of three fertilizations,manure treatment is the second and chemical treatment is minimum.Along with the increasing year of fertilization,the molecular structure of the HA in soil has the tending to aging,organic materials can slow or inhibit this trend.