Stydies On Change Course And Influence Factors Of Soil Phosphorus Pools Of Agriculture Black Soil

The research was studied on phophorus pool of different reclamation black soil at Zhaoguang farm ,the soil was selected in 9km~2 and the slope was 1-3°through investigation. The soil separately was virgin, reclamation of 2* reclamation of 8, reclamation of 15, reclamation of 30, reclamation of 50,the soil sample of 100 reclamation was sampled from Hailun experiment station. The study was on the change characteristics of soil phosphorus pool of profile of different reclamation, which to find change regulation of phosphorus pool of agricultural black soil from time and space. The other experiment was on long-term experiment of hanlun experiment station. The study was on the changes of total P, available P, organic P and 6 inorganic P on different agricultural methods, which can compare the effect of different agricultural methods to black soil phosphorus pool.The change of total P was small with reclamation. The quantity of available P markedly increased with reclamation for the effect of fertilizer. The amount of organic P markedly decreased with reclamation, which was same with the popular standpoint, that is the content of organic P was reduced for the organic matter was decomposed since the virgin was reclaimed. The changes of 6 different phosphorus were different after reclamation for they have different quanlity. The quantity of Ca2-P was affected easily by fertilizer for its chemical nature was active and was increased with reclamation, which was increased 30.0-123% compared to virgin. The amount of Cag-P was increased after reclamation and increased 48.9-128% compared to virgin. Its amount kept stable after a certain reclamation. The quantity of Al-P was increased 1.87-35.1% compared to virgin after reclamation. The absolute and relative amount of Al-P was increased with reclamation. The regulation of Fe-P amount in 0-160cm was not obvious after reclamation. The effect of reclamation to O-P and Cai0-P was small for theirs chemical characteristic were stable. Above all, the change of phosphorus that was used easily by crop and the phosphorus that was first changed into after fertilizer was applided into soil. But the change of phosphorus that was used difficultly by crop for its characteristic was stable.The amount of available P, Ca2-P and Al-P decreased from surface to lower level, and decreased to the lowest at 20-40cm or 40-60cm, then began to increased. The amount of total-P and organic P decreased from surface to 40-60cm (total P) or 60-80cm-100-120cm (organic P) where the content were lowest, and then the amount keep stable. The quantity of Cas-P on the whole profile was low. The amount of Cag-P of virgin, reclamation of 2, reclamation of 8, reclamation of 30 on some profile were 0 and were mostly under 20-40cm. The change regulation of O-P and Caio-P was not obvious.The effect of fertilizer to other forms phosphorus was obvious but for O-P and Ca10-P.The effect of different cultivation to the amount of total-P, Fe-P, O-P and Caio-P wassmall, but to available P, Ca2-P, Al-P and Cag-P was obvious.The water was the factor that affected phosphorus pool apart from fertilizer. The increase of water can quicken the transform of fertilizer in soil in the base of only applying fertilizer. But the effect of adding organic fertilizer was obvious in dry condition.The effect of tillage to phosphorus pool of black soil was small and the regulation was not obvious. The standpoint that deep plowing can reduce the content of organic phosphhhorus much more than the flat tillage and revolve tillage, which need confirm in future.