Selecting And Action Mechanism Of Soil Phosphorus Solubilizer

Phosphate fertilizer is an important material guarantee for agricultural production.However,along with the application of phosphate fertilizer to the soil,70%to 90% phosphorus is fixed by the soil as insoluble phosphorus.In this paper,Zhengzhou fluvo-aquic soil is used as the research object,through indoor soil culture experiment method,to find a suitable phosphorus solubilizer,and to study the method of activating the insoluble phosphorus in the soil to become effective phosphorus.A total of 16 kinds of phosphorus solubilizers,including organic acids,high molecular polymers,high surface active minerals and other types,were selected as the preliminary screening objects,and Five kinds of phosphorus solubilizers with better effects were screened out for systematic research,and the effect of addition amount on the available phosphorus in soil was explored;the study took the significant effect of γ-polyglutamic acid as an example,through the path analysis of soil inorganic phosphorus form changes and correlation,and analysis of the correlation coefficient,and the analysis of the decision coefficient.The mechanism of phosphorus solubilization on Zhengzhou fluvo-aquic soil;finally,the orthogonal experiment was used to explore the compound effect of different types of phosphorus solubilizers.In order to strengthen the effect of the phosphorus solubilizer,the study added insoluble low-grade phosphate rock powder to the soil;the Changtu sandy soil was used as the contrast soil to observe the effect of the phosphorus solubilizer in different types of soil.The main conclusions are as follows:Oxalate has the best effect on phosphorus solubilization among organic acid phosphorus solubilizers.The effective phosphorus content can be increased by 46.85%on average,followed by lignin and humic acid.The effective phosphorus content has been increased by 7.22% and 7.08% respectively,and succinic acid has the worst effect.The effective phosphorus content decreased by 22.03% instead.Γ-polyglutamic acid has the best effect among the high molecular polymer phosphorus solubilizers.The effective phosphorus content can be increased by 66.08% on average,followed by polyacrylamide and polyvinyl alcohol,and the effective phosphorus content can be increased by 11.97% and 5.22% respectively.Among the high surface active mineral phosphorus solubilizers,zeolite powder has the best effect.The effective phosphorus content can be increased by 14.74% on average,followed by diatomaceous earth and sepiolite powder,and the effective phosphorus content can be increased by 11.30% and 6.49% on average.Among other types,EDTA-2Na has the best effect on dissolving phosphorus in phosphate rock powder.The effective phosphorus content can be increased by 21.14% on average,and the effective phosphorus content of sulfur powder can be increased by 4.47% on average.In general,γ-polyglutamic acid has the most significant phosphorus-resolving effect on the Chaozhou soil in Zhengzhou,followed by oxalic acid.The results of a systematic study of five kinds of phosphorus solubilizers with better effects show that on the Zhengzhou fluvo-aquic soil,the order of the average highest increase rate of available phosphorus for the five phosphorus solubilizers is:γ-polyglutamic acid(47.34%)> oxalic acid(31.12%)>zeolite powder(10.13%)>amino acid(8.23%)>polyacrylamide(6.66%);on Changtu sandy soil,oxalic acid(67.18%)>polyacrylamide(25.76%)>γ-polyglutamine Acid(16.16%)>amino acid(0.31%)>zeolite powder(0.30%).Compared with Changtu aeolian sandy soil,γ-polyglutamic acid can exert more phosphorus solubilizing effect on Zhengzhou fluvo-aquic soil.Path analysis results show that the direct path coefficient of octacalcium phosphate is large,so it has the greatest direct effect on available phosphorus.The increase of octacalcium phosphate will cause the increase of available phosphorus content;aluminum phosphate,iron phosphate and closed storage phosphorus The direct path coefficient of is negative,indicating that the increase of aluminum phosphate,iron phosphate and closed storage state phosphorus will lead to a decrease in the effective phosphorus content.The decision coefficient shows that octacalcium phosphate(0.538)and dicalcium phosphate(0.515)are the main decision factors for available phosphorus;closed storage phosphorus(-1.281)and aluminum phosphate(-0.222)are the main limiting factors for available phosphorus content.It can be seen that to increase the effective phosphorus content,the content of dicalcium phosphate and octacalcium phosphate in the soil must be increased,and the conversion of dicalcium phosphate and octacalcium phosphate in the soil to closed storage state phosphorus and aluminum phosphate must be restricted.The compounding results show that when γ-polyglutamic acid 2.5 g/kg,sulfur powder 1.5 g/kg,zeolite powder 0.5g/kg,and polyacrylamide 2.5 g/kg are used together,the average increase in soil effective phosphorus is the highest.After 90 days,its effective phosphorus increase rate reached 80.62%.The 16 sets of compound data were analyzed by variance analysis,and the best compound plan was obtained according to the results of the variance analysis: phosphate rock powder 5.0 g/kg,γ-polyglutamic acid 0.5 g/kg,sulfur powder 1.5 g/kg.