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通过田间小区模拟酸雨实验,研究酸雨胁迫下赤红壤不同磷素形态变化的方向和程度。结果表明,原位模拟酸雨影响下,一定强度(pH≥4.0)的酸雨胁迫能有效促进有效磷的释放,而当pH<4.0强度酸雨胁迫时有效磷的释放随pH值降低逐渐受到抑制。随酸雨酸度的增强,土壤酸性磷酸酶和微生物量磷均呈现先升高后降低的变化趋势,可见一定强度酸雨胁迫能促进溶磷微生物和磷酸酶活性,而当高强度酸雨胁迫时土壤微生物活动逐渐受到抑制。无机磷组分中Al-P、Ca-P和Fe-P含量均随酸雨酸度的增强而降低,土壤O-P含量没有显著变化。相关分析发现,有效磷含量与微生物量磷、酸性磷酸酶呈极显著正相关,表明此时土壤有效磷变化与有机磷矿化关系最为密切。有效磷含量与各种形态无机磷(Al-P、O-P、Ca-P和Fe-P)含量之间也有较强的正相关性,表明土壤生态系统磷素转化是一个自我调节的动态平衡过程,且在一定条件下可以相互转化。
Field experiments were conducted to study the direction and degree of morphological changes of different phosphorus species in latosolic red soil under acid rain stress. The results showed that the acid rain stress of a certain intensity (pH≥4.0) could effectively promote the release of available phosphorus under the influence of acid rain in situ, while the release of available phosphorus was gradually inhibited with the decrease of pH when the acidity was lower than 4.0. Soil acid phosphatase and microbial biomass P increased firstly and then decreased with the increase of acid rain acidity. It can be seen that some acid rain stress could promote the activity of phosphate solubilizing microorganisms and phosphatase. However, when high acid rain stress, soil microbial activity Gradually suppressed. The contents of Al-P, Ca-P and Fe-P in inorganic phosphorus fractions decreased with the increase of acid rain acidity, while the content of O-P in soil did not change significantly. Correlation analysis showed that there was a significant positive correlation between available phosphorus and microbial biomass phosphorus and acid phosphatase, which indicated that the change of soil available phosphorus was the most closely related to the organic phosphorus mineralization. There was also a strong positive correlation between available P content and the contents of various forms of inorganic phosphorus (Al-P, OP, Ca-P and Fe-P), indicating that the phosphorus conversion in soil ecosystem is a self-regulating dynamic equilibrium process , And under certain conditions can be transformed into each other.