Vicia Villosa Root Exudates Improve the Mobilization of Available P, K, Zn and Fe in Three Types of Purple Soil

摘要

Root exudates play a major role in the mobilization of sparingly soluble nutrients in the rhizosphere. Purple soils have poor fertility as a result of soil erosion and certain soil characteristics. In this study, we examined how root exudates of hairy vetch (Vicia villosa) affected soil-available nutrients in three types of purple soil, by using solution-cultivation and soil-cultivation methods. Root exudates were collected by solution cultivation and a soil-cultivation experiment was carried out with two exudate treatments (low amount and high amount). In all three types of purple soil, high amount of root exudates significantly increased available P, K, Zn, Fe (P<0.05). The activation effects of exudates on soil available P and Zn were most substantial in alkaline purple soils. Soil available K was most primary in neutral purple soils, and soil available Fe was major in acidic purple soils. These results suggest that planting hairy vetch in winter fallow increase specific nutrients of purple soils in the study area because of the mobilization of root exudates and different types of soil.