Analysis On The Effects Of Organic Farming On The Primary Physicochemical Properties And The Heavy Metal Content Of Saline Soil

This study organic farming base in Heilongjiang Daqing Lamadian town as positioning monitoring, select its organic farming is saline soil and surrounding environment conditions similar conventionally grown in saline soil as the research object, and choose the Heilongjiang Qingan, Chahayang, Beian organic farming base of the three regions and the surrounding normal planting farmland as a census point sampling investigation and study, to compare organic and conventional farming two farming form different impact on the main physical and chemical properties and soil heavy metal and its effect on improvement of soil salinization.Research results show that:(1) Organic farming can effectively reduce the soil bulk density, increase the soil aggregate quantity: Including a 5.1% drop in anchor point average soil bulk density, different length of organic soil bulk density decreased with the increase of the age.Organic farming on soil water stability of large aggregate(> 0.25 mm) has obvious increase effect, with the increase of organic farming is fixed number of year, 0.25 ~ 0.5 mm,0.5 ~ 2 mm and > 2 mm increased aggregate content has a different level.(2) The organic farming can improve soil nutrients, with the increase of organic farming life has some changes: organic farming conditions between soil organic matter content were higher than conventional farming, and increased with the increase of organic farming is fixed number of year.In general, organic farming soil TN, TP is conventionally grown to some extent, organic farming is the soil available phosphorus and available potassium content has obvious improvement, organic farming life longer, the more obvious role.(3) Organic farming can improve soil microbial biomass carbon and nitrogen content:Anchor point organic microbial biomass carbon and nitrogen content is conventionally grown by 22.44% and 38.96% higher than that of average, census point organic microbial carbon,nitrogen content is higher than that of also have different degrees of conventionally grown,along with the increase of organic farming is fixed number of year of growth.(4) Organic farming methods can lower part of the content of heavy metals in soil: In addition to the zinc, the As anchor point are less than conventionally grown organically grown heavy metals, and organic farming is heavy metal content in general census point all fell, Cd and Hg content decreased obviously.Zinc in the soil and the As content increases with the increasing length of organic farming, Cd, pb and Hg content decreased with increasing length of organic farming, different length of organic soil Cu, Cr content has no obvious change rule.(5) Organic farming for the amelioration of soil salinity have obvious: Effectively reduce the soil pH, its effect is more obvious with the increase of organic farming is fixed number of year.Organic farming to increase soil cation exchange capacity has a significant effect, reduce the exchangeable sodium content in the soil at the same time, thereby reducing soil alkalization degrees.Along with the increasing length of organic soil alkalization degree reduced gradually, the largest reduction of 20.8%.Organic farming soil total alkalinity and total salt were lower than conventional planting, and decreasing with the increase of organic farming is fixed number of year.