Study On Adsorption-desorption Properties Of Different Organic Matter Black Soil Phosphorus

Phosphorus is an important nutrient element for plant growth.It also plays an important role in high yield of crops.Phosphorus is easy to be fixed in soil,difficult to move and low in effectiveness by many factors.black soil is a valuable natural resource and is an important production base of grain.However,due to cultivation and degradation,the content of organic matter is uneven distribution,which is generally low in the South and North,and different organic content of black soil contains different nutrients,including phosphorus.In order to investigate the effect of organic matter on the adsorption and desorption characteristics of phosphorus in black soil,three fields of black soil with different organic matter content were selected in this experiment,which were studied in Bei'an black soil?50.96 g/kg?,Shuangcheng black soil?28.5 g/kg?and East agricultural campus black soil?17.71 g/kg?,and the analytical characteristics of phosphorus adsorption were studied under the conditions of adding carbon,low molecular weight organic acid and iron oxide.It will provide theoretical basis for exploring the phosphorus transformation and its influence factors in black soil.The results are as follows:?1?Isotherm adsorption characteristics of different organic matter black soilThe tested black soil samples were added to 0.5,10,20,40,60 and 100 mg/L KH₂PO₄standard solutions respectively.After the adsorption equilibrium,the phosphorus adsorption capacity of the black soil,Shuangcheng black soil and Bei'an black soil was measured with the concentration of 0.65-660.65 mg/kg,1.03-722.58 mg/kg and 3.03-754.83 mg/kg respectively,indicating that the higher the soil organic matter was,the stronger the phosphorus adsorbability was,that is,the phosphorus adsorption capacity was shown as the East farmer.The black earth of the campus<Shuangcheng black soil<Bei'an black soil.?2?Phosphorus desorption characteristics of different organic matter black soilThe tested black soil samples were added with deionized water.The soil and water ratio were1:1,2:1,3:1,5:1,10:1,15,1.The variation range of phosphorus solution absorption with the concentration in the black soil,Shuangcheng black soil and Bei'an black soil was 0.29-3.91 mg/kg,0.28-3.48 mg/kg and 0.21-2.27 mg/kg respectively,indicating that the higher the content of the organic matter,the greater the desorption amount was,that is,the size of phosphorus solution absorption was manifested in the black soil of the East agricultural campus.Shuangcheng black soil>Bei'an black soil.?3?Change of phosphorus adsorption characteristics of iron oxide black soil.Compared with the black soil that did not remove iron oxide,the phosphorus adsorption capacity of different organic matter black soils decreased by 40%-75%,and the adsorption capacity of the organic matter in the black soil decreased by 5.9%-17.33%compared with the previous phosphorus adsorption.?4?Effect of low molecular weight organic acids on phosphorus adsorption characteristics in black soil.Organic acids have a significant reduction in the adsorption of phosphorus in black soil,in which the action of citric acid is stronger than that of oxalic acid,and with the increase of the concentration of organic acids,the adsorption of phosphorus in the black soil decreases gradually.?5?Effects of different carbon sources on phosphorus adsorption characteristics of black soil and East Campus black soil in Bei'an.After adding different carbon sources,such as organic fertilizer,biological charcoal and glucose,the content of organic matter in soil of Bei'an black soil and East agricultural campus 90d increased significantly,which were 70.25,61.87,78.75 g/kg,39.8,36.4,49.03 g/kg,among which,the organic matter added to the soil added with glucose was the most obvious,but the organic matter added to the soil carbon was less.Bei'an black was black.The soil added with different concentration of phosphorus standard solution,the adsorption amount of phosphorus adsorbed with the concentration is 3.03-754.83 mg/kg,the adsorption amount of phosphorus in Bei'an black soil added to biological carbon is 3.64-784.66 mg/kg,and the adsorption capacity of phosphorus by adding glucose is 3.78-827.75 mg/kg,and the adsorption capacity of phosphorus by adding organic fertilizer is 2.29-582.60 mg/kg,and the black soil of Dong Nong campus is added to different concentration of phosphorus standard solution.The adsorption amount of phosphorus is0.65-660.65 mg/kg in turn,and the phosphorus adsorption capacity of the black soil on the East agricultural campus is 3.37-701.86 mg/kg in turn.The phosphorus adsorption amount is 2.56-738.58 mg/kg,adding organic fertilizer to the black soil of Dong Nong campus with glucose culture,and the phosphorus absorption amount is in turn:-60.05,-45.95,-36.75,30.84,136.93,492.07 mg/kg,indicating the biological carbon and the biological carbon.Glucose can increase the phosphorus adsorption strength of the black soil,the organic manure inhibits the adsorption process of the black soil phosphorus,increases the amount of phosphorus solution absorption in the black soil,and reduces the amount of phosphate fertilizer application when the black soil is applied with organic fertilizer.