河西走廊盐渍土不同种植年限苜蓿根际磷含量变异特征

盐渍土的改良利用已有大量研究,但在盐碱地种植牧草的报道并不多.试验以河西盐渍地2、3、4、5、8龄苜蓿Medicago sativa的根际和非根际土壤为材料,研究土壤全磷及有效磷含量变异特征,结果表明,所有株龄苜蓿根际与非根际土壤全磷含量差异不显著,有效磷含量根际高于非根际土壤.在种植苜蓿的前5年,有效磷在根际与非根际均显著增加,种植8年开始降低,而全磷无显著变化规律.根际pH值低于非根际,但根际酸化不明显.根际与非根际土壤有效磷和全磷含量,根际pH值和有效磷含量相关性不显著.

The changeable characteristics of phosphorus content in rhizosphere soils in different years alfalfa pastures in Hexi Corridor saline soil

Lots of research have been done about the improvement and utilization of the saline soil,but reports about the forage that planted in such area is limited.The changeable characteristics of total P and available P content in non-rhizosphere and rhizosphere soils in 2-year,3-year,4-year,5-year and 8-year alfalfa pasture in Hexi Corridor saline soil were discussed in this study.This study showed that total P content was not significantly different between the rhizosphere soils and the non-rhizosphere soils but the available P content in the rhizosphere was significant higher than that in the non-rhizosphere soils cross each age alfalfa pasture.The available P content in rhizosphere and non-rhizosphere soils increased for 2-year,3-year,4-year and 5-year alfalfa pasture but reduced at 8-year alfalfa pasture,however,the total P content showed no regular rules among different years alfalfa pasture.The pH value of rhizosphere soils was lower than that of non-rhizosphere soils,but further acidification was not observed.Regression analyses indicated that there was no significant correlation between the total P and available P content in non-rhizosphere soils,and between the pH value and available P content in rhizosphere soils.