生物覆盖对冰脆李人工林土壤养分及酶活性的影响

Mulching Effect on Soil Nutrient Contents and Enzyme Activities Under Prunus salicina Plantation

以不同覆盖材料(红花三叶、紫云英-过路黄(1∶3)、紫花苜蓿-过路黄(1∶3)、苦蒿,覆盖量均为5.0 kg/m2),不同覆盖量(红花三叶2.5、5.0、7.5 kg/m2)为处理,不覆盖为对照;探讨不同覆盖处理对喀斯特地区冰脆李林下土壤氮磷养分和酶活性的影响,结果表明:与对照相比,红花三叶、紫云英-过路黄(1∶3)、紫花苜蓿-过路黄(1∶3)对土壤全氮、全磷、水解氮、有效磷、酶活性均有显著影响;苦蒿的影响不显著。土壤脲酶和磷酸酶活性与土壤氮磷养分具有较高的相关性。不同处理对土壤养分含量影响的排序为:红花三叶>紫云英-过路黄(1∶3)>紫花苜蓿-过路黄(1∶3)>苦蒿>CK;红花三叶覆盖量7.5 kg/m2>5.0 kg/m2>2.5 kg/m2>CK;红花三叶覆盖量5.0 kg/m2覆盖40～120 d,土壤氮磷养分变化趋势较一致,均为先上升后下降。

An experiment was conducted by taking different mulching materials and varied mulching quantity in order to study mulching effect on soil nutrient contents and soil enzyme activities in the soil under Prunus salicina plantation in the Karst region. The mulching materials included Trifolium pretense, Astragalus siniucus -Lysimachia christinae （ 1 ： 3 ）, Medicago sativa - Lysimachia christinae （ 1 ： 3 ）, and Conyza blinii , with no mulching as the con- trol. Three levels of mulching quantity were set as 2. 5 kg/m2, 5.0 kg/m2 and 7.5 kg/m2 in the experiment. Com- pared to the control, the results showed that the mulching with Trifolium pretense, Astragalus siniucus -Lysimachia christinae （ 1 ： 3 ）, Medicago sativa - Lysimachia christinae （ 1 ： 3 ） significantly increased the contents of total soil N, total soil P, the alkali-hydrolyzable N, the available P and the soil enzyme activities. The urease and phosphatase enzyme activities in the soil were highly correlated with the N and P nutrient contents in the soil. The effect of mulching materials on the soil nutrient content was ordered as Trifolium pretense 〉 Astragalus siniucus - Lysimachia christinae （ 1 ： 3 ） 〉 Medicago sativa - Lysimachia christinae （ 1 ： 3 ） 〉 Conyza blinii 〉 CK. The effect of mulching amount by Trifolium pretense was ordered as 7.5 kg/m2 〉 5.0 kg/m2 〉 2. 5 kg/m2 〉 CK. The contents of soil N and P nutrients varied similarly between the 40 and 120 days after having been mulched with the Trifolium pretense, which increased at the early stage and then decreased along with the time.