晋西北黄土高原丘陵区小叶锦鸡儿人工灌丛不同生育阶段土壤肥力特征研究

对晋西北黄土高原丘陵区不同生长年限的小叶锦鸡儿人工灌丛土壤肥力特征进行了研究,结果表明:小叶锦鸡儿人工灌丛能显著提高土壤肥力。随着小叶锦鸡儿人工灌丛生长年限的增加,土壤容重降低,土壤孔隙度增加,土壤透气透水性增强,土壤有机质、全氮有逐渐增加的趋势,而有效磷、速效钾的含量大幅度下降,微量元素也有下降的趋势。同时,随着生长年限的增加,小叶锦鸡儿人工灌丛土壤酶活性逐渐提高,其中20年生小叶锦鸡儿灌丛土壤酶活性最高。根际土壤研究表明,小叶锦鸡儿人工灌丛根际土的pH均小于根外土,土壤有机质、全氮、速效钾在根际土中均有一定程度的富集现象;而5年生的小叶锦鸡儿灌丛根际土壤的有效磷含量则出现了亏缺。

Soil Fertility Characteristics Induced by Caragana microphylla Plantation at Different Growing Stage on Loess Plateau in North- west of Shanxi Province

Caragana microphylla was the dominant plant life form on Loess Plateau in North - west of Shanxi Province, the experiment was conducted to study soil physical and chemical characters, soil enzyme activities and soil rhizosphere effect at different growing stage. The results showed that soil physical and chemical properties in Caragana microphylla plantation were all well improved with the age increasing, soil bulk density decreased, soil porosity, saturated water holding capacity and water permeability improved, the content of soil organic matter and total N increased, while active P and available K largely decreased. Meanwhile, the soil enzyme activities in Caragana microphylla plantation were enhanced with the growing years increasing, and the soil enzyme activities in 20 - age plantation were the highest. There was an obvious rhizosphere effect in all growing stages of Caranaga microphyUa plantation. The content of organic matter, total N and available K in rhizosphere soil were all higher than those in near rhizoshphere soil, but the Content of olsen - P in 5 - age plantation was remarkably deficient in rhizosphere soil. The pH value in rhizosphere soil was lower than that in near rhizosphere soil.