不同施磷水平对红壤酸害的影响

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

[目的]探讨南方丘陵区不同施磷水平对红壤酸害值的影响。[方法]在盆栽模拟试验中,以墨西哥玉米为试材,采用南方长期施尿素20年的严重酸化第四纪红壤做土培,以石灰作土壤pH值调节剂,通过对墨西哥玉米的生长发育状况和植株养分含量及土壤肥力变化的评价,研究不同施磷水平对红壤不同酸害的影响。[结果]在酸性红壤上施用磷肥,能够增加墨西哥玉米的植株高度、分蘖数、地上部和地下部生物产量,促进植株对土壤氮、磷、钾、钙的吸收,而且随pH值升高,施磷能极大增强对酸害的缓解能力;同一石灰施用量下,植株全氮、磷、钾、钙含量和土壤速效磷、水溶性镁含量随施磷量增加而增加,红壤酸害缓解程度与施磷量成正相关性。[结论]施用磷肥能够缓解红壤的酸害。

[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.