不同施肥处理下红壤旱地速效磷时空变化及其影响因子

在不同施肥处理下,利用田间试验,研究了2007年3、5、7、9和11月湖南地区红壤旱地土壤速效磷含量的时间变化和剖面中的垂直变化.结果表明:各处理小区土壤中速效磷的含量均在表层较高,而底层较低;土壤速效磷含量在3月至9月和9、11月分别呈降低-升高的趋势,其中在3月份氮磷配施处理表层土壤的含量最高,达12187 mg·kg-1.土壤有机质、团粒结构以及pH值均是影响土壤速效磷含量的重要因子,其中有机质和速效磷含量间呈显著正相关(P<005).红壤有机质含量较低,生产中应增加有机肥的施用量;对照小区各层土壤团聚体与速效磷含量呈指数曲线变化.

Time-spatial variability and influenced factors of available phosphorus under different fertilizer treatments in dry land of red soil

Available phosphorus content varied with months and soil profile, which was studied under different fertilizer treatments in dry land of the red soil by field experiment. The results indicated that available phosphorus content of each treatment was higher in surface soil layer and lower in bottom layer. The content of available phosphorus declined during March to September first, then rose during September to November, and it reached the highest content in surface soil layer of nitrogen and phoshorus plot in March, 121. 87 mg·kg~(-1). Organic matter, aggregates structure and pH were important factors. Available phosphorus had a sharp positive relation with soil organic matter (P<0. 05). However, the content of organic matter in red soils was still low. Therefore, more attention should be paid to the application of organic fertilizers. Soil aggregates and available phosphorus had a significant relationship in control plot and changed with exponential function.