Effects Of Different Phosphorus Level Manure On Alfalfa Production Performance And Soil Nutrients In Coal Mining Subsidence Areas

Phosphorus is one of the key factors to restrict the reclamation process of the mining area and affect plant growth.Because there are some scientific problem,such as the low effectiveness of soil phosphorus and unclear effect of different types of the manure and different phosphorus levels on soil improvement in the reclamation area of coal mining subsidence area,the coal mining subsidence area（Piancheng Village,Xiaoyi City,Shanxi Province）was taken as the research object in this experiment,and alfalfa was used as the test material.The reclaimed soil was applied with 0kg/hm²（P0）,30kg/hm²（P30）,60kg/hm²（P60）,90kg/hm²（P90）,120kg/hm²(P₁₂₀)and 150kg/hm²(P₁₅₀)chicken manure（CN）,pig manure（PG）and cow manure（CE）at six phosphorus levels.The effects of organic fertilizers with different phosphorus levels on alfalfa production performance,nutrient quality and soil nutrients were analyzed to provide a scientific basis for alfalfa production and soil nutrient recovery of coal mining subsidence areas.The main findings were as follows:1.Under the treatment of manure with different phosphorus levels,the value of stem thickness,plant height,leaf-stem ratio and yield of alfalfa increased with the increase of phosphorus application level.All indexes of three organic fertilizers were the highest under P₁₂₀ and P₁₅₀ treatment.Having comprehensive analysis to the hay yield,crude protein（CP）,crude fat（EE）,crude ash（Ash）,neutral detergent fiber（NDF）,acid detergent fiber（ADF）and relative feeding value（RFV）of alfalfa by gray correlation method,It could be seen that cattle manure（CE）applying along with alfalfa in the coal mining subsidence area and the treatment of CEP₁₂₀ had the best performance of indicators of alfalfa.2.The application of chicken manure and cow manure increased the phosphorus content of alfalfa with the increase of phosphorus application level,and the phosphorus content of the plant in pig manure under the P₁₂₀ treatment had a decrease tendency.The phosphorus absorption coefficient of manure with different phosphorus levels reached the peak in P₁₂₀ treatment.With the increase of the phosphorus application level,the recovery rate of phosphate fertilizer in the season decreased with chicken manure and cow manure applied,and the phosphorus recovery rate of pig manure applied under P₁₂₀ treatment also reached the highest.3.The organic matter,total phosphorus and total nitrogen content in the soil increased with the increase of the phosphorus application level,and the value of the effective phosphorus content and the absorption coefficient of phosphoric acid in the soil reached the highest at P₁₂₀ treatment.under the treatment of chicken and pig manure(P₁₂₀、P₁₅₀),the absorption coefficient of organic matter,total phosphorus,total nitrogen,available phosphorus and soil phosphoric acid in the soil reached the highest.There was a very significant correlation between the absorption coefficients of total phosphorus,available phosphorus and phosphoric acid.In summary,there were the best production performance and nutritional quality of alfalfa with the application of cattle manure under P₁₂₀（17.92kg/hm²）treatment in coal mining subsidence area,and the phosphorus content,phosphorus absorption content and seasonal recovery rate of alfalfa were the best with P₁₂₀ and P₁₅₀ treatment of pig manure,and the application of chicken and pig manure could significantly increase the soil nutrient content of coal mining subsidence area.