施肥对农田土壤动物群落结构的影响

为研究施肥对土壤动物群落结构的影响,以尿素为施肥材料,采用大型手捡和干、湿漏斗法,以不施肥处理为对照(CK),对施肥量分别为225 kg·hm^-2(T1)、450 kg·hm^-2(T2)、900 kg·hm^-2(T3)、1 800 kg·hm^-2(T4)、3 600 kg·hm^-2(T5)等5个施肥处理下的土壤动物群落特征进行调查。结果显示:试验捕获的土壤动物分属3门13纲19目40科,各处理的土壤动物平均密度排序为CK>T2>T1>T3>T5>T4,类群数排序为T1>CK>T2>T4>T5>T3。随着施肥量增加,大型和中小型土壤动物的平均密度总体减少。同时,各处理中,T2处理的多样性指数和优势度指数最低,而均匀度指数最高。总体来看,过量施肥会减少土壤动物数量,降低土壤动物多样性,对土壤动物群落结构产生影响。

Effect of fertilization on soil fauna community structure in farmland

In order to explore the impact of fertilization on soil fauna community structure, urea was selected as test fertilizer, and an experiment with different fertilizing amounts, i.e. 225 kg·hm^-2 (T1), 450 kg·hm^-2 (T2), 900 kg·hm^-2 (T3), 1 800 kg·hm^-2 (T4), 3 600 kg·hm^-2 (T5), and plot without fertilizer as control (CK) was carried out. The hand-picked concentrations and wet and dry separation funnel were recorded to reflect the characteristics of soil fauna communities in the survey. It was shown that all the collected soil fauna samples went to 3 phyla, 13 classes, 19 orders, 40 families. The order of the average density of soil fauna of different treatments was as CK>T2>T1>T3>T5>T4. The order of species quantity of different treatments was as T1>CK>T2>T4>T5>T3. With the increasing application amount of fertilizer, the average density of both macro-fauna and nematodes and meso-fauna in soil showed a decreasing trend. Among all the treatments with fertilization, T2 exhibited the lowest Shannon-Wiener index and Simpson index, and the highest Pielou index. In general, over application of fertilizer would reduce the quantity of soil animals, the diversity of soil fauna community, and impact soil fauna community structure.