植被类型对土壤剖面盐分离子迁移与累积的影响

摘要

[Objective] The characteristics of soil salt ions in soil profile were investigated under different vegetation types, and the purpose was to provide a theoretical basis for excavate and sustainable use of salinization soil. [Method] The object of study was orchard salinization soils in Qin'an County of Gansu Province. A field experiment was carried out to probe into the effects of vegetation type (barley, maize, apple fruit trees and the bare land) on soil salt and ions. [Result] The results showed that in semiarid salinization area, salt in soil profile of the bare land always was in a state of accumulation, the intensity and depth of salt accumulation was gradually increased with time elapsing. Salt accumulation was restrained in soil profile in barley and maize planting land at the late growth stage. However, there were two peak values on salt accumulation in soil profile in fruit trees planting land. The first peak value was from May to June, salt mainly accumulated in the soil layers of 10-30 cm. The second peak value was in middle August, salt mostly accumulated in the soil layers of 30-50 cm. [Conclusion] Under the condition of agro-forest vegetation in semiarid, vegetation types affected the periods of salt ions accumulation, the intensity of salt ions accumulation, and the place of salt ions accumulation. There was a significant influence of planting barley, maize and apple fruit trees on the content of salt, Cl- and water soluable Ca2+ in soil profile.%[目的]探讨不同植被类型条件下土壤盐分累积与离子分异特征,对于挖掘、利用盐渍土资源、促进农业可持续发展提供科学依据.[方法]以甘肃省秦安县次生盐渍化果园土壤为研究对象,采用大田试验研究种植大麦、玉米、果树和裸露地块(CK)对土壤剖面盐分离子迁移的影响.[结果]在半干旱盐渍化地区,裸露地块土壤剖面盐分始终处于累积状态,随着时间的推进,盐分累积的强度和深度逐渐增大;种植大麦、玉米,在生育后期具有明显的抑盐、脱盐的功效;而种植果树,土壤盐分累积有两个峰值,第一个峰值出现在5-6月,土壤盐分主要累积在大约10-30 cm土层;第二个峰值在8月中旬,土壤盐分主要累积在30-50 cm土层.[结论]在半干旱地区的农林植被条件下,植被类型影响土壤剖面盐分离子迁移累积的时期、强度和部位.种植大麦、玉米、果树对土壤剖面盐分、C1、水溶性Ca含量有明显的影响.