Effect of Acid Hazards of Red Soil under Different P Application Levels

[Objective] The study aimed to discuss the effects of P application at different levels on the acid hazards of red soil in south hills area in China.[Method] In the pot simulation test,with the Mexico maize as the tested material,taking the quaternary red soils with serious acidification which had been applyed urea for 20 years in southern China in the soil culture,using the lime as the pH regulator,the effects of P application at different levels on the acid hazards of red soil were studied through the evaluation on the growth and development of Mexico maize and the change of soil fertility.[Result] P application on the red soil with acidity could increase the plant height,tiller number,biological yields of overground part and underground part and promote the plant absorption to N,P,K and Ca in the soil.P application could greatly enhance the relieving ability for the acid hazards of red soil with the rising of soil pH.The contents of total N,P,K and Ca in the plant and the contents of available P and water-soluble Mg in the soil were increasing with the rising of P application rate under the same lime dosages.The relieving degree of acid hazards of red soil showed the positive correlation with P application rate.[Conclusion] P application could relieve the acid hazards of red soil to different extent.