胡桃揪、落叶松纯林及其混交林根际土壤有效磷特性的研究

用剥落分离采集胡桃揪（Juglans mandshurica）、落叶松（Larix gmelinii）纯林及其混交林根际与非根际土壤并分析有效P含量特性。结果表明，落叶松纯林根际土有效P含量较非根际土高出55．8％，而胡桃揪纯林根际土有效P含量较其纯林仅高10．1％，表现出落叶松根第泽根际P较强的活化能力。树种混交后，借助落叶松根系的作用使混交林中胡桃揪根际土有效P含量较其纯林高出45．2％，通过P的吸附／解吸及无机P分级等方面，对落叶松根际土壤有效P含量较高的原因进行了分析。

Characteristics of available P in the rhizosphere soil in pure Juglans mandshurica and Larix gmelinii and their mixed plantation.

The rhizosphere and non rhizosphere soils were sampled in the pure and mixed plantations of Juglans mandshurica and Larix gmelinii by peeling the adhering soil of the roots, and the available P content were analyzed. The results showed that the available P content in the rhizosphere soil in the pure Larix gmelinii was 55.8% higher than that in the non rhizosphere soil, while the available P content in the pure Juglans mandshurica was higher thanthat in the non rhizosphere soil by 10.1%. The roots of Larix gmelinii had important effect on mobilizing P in the rhizosphere soil. The available P content in rhizosphere soil of Juglans mandshurica in the mixed plantation was higher than that in the pure plantation by 45.2% due to the effects of the roots of Larix gmelinii . The mechanism by which the available P content in the rhizosphere soil of Larix gmelinii was much higher was elucidated by means of P absorption, P desorption, and inorganic P gradation.