Soil nutrients and microorganisms with simulated acid rain stress and Cryptomeria fortunei litter

Key words: 
• forest ecology /
• Cryptomeria fortunei /
• acid rain /
• litter /
• soil nutrient /
• soil microorganisms

Abstract: To clearly show the effects of acid rain stress and litter on soil nutrient content and soil microorganism numbers, rhizosphere soil of Cryptomeria fortunei seedlings was tested with combinations of simulated acid rain （pH 3.0, 4.0, and 5.6） and litter （L1-400 gm－2, L2-500 gm－2, and L3-600 gm－2）. Results showed that soil nutrient content and the quantity of bacteria and actinomyces decreased for the acid rain treatment; whereas, fungi increased with pH 3.0 ＞ pH 4.0 ＞ pH 5.6. Also, soil N, P, K, and quantity of microorganisms increased as litter increased （L3 ＞ L2 ＞ L1）. For pH 5.6 + L2 and pH 4.0 + L2 treatments no significant differences in soil N, P, and total K were found, but available K significantly increased （P ＜ 0.01）. With the pH 3.0 + L2 treatment, total N, available N, total P, and total K significantly decreased （P ＜ 0.01） as did available P （P ＜ 0.05）. For the pH 5.6 + L2 treatment, soil bacteria and actinomyces significantly increased （P ＜ 0.05）. With the pH 3.0 + L2 treatment, soil bacteria and actinomyces significantly decreased （P ＜ 0.01）. Also, for pH 4.0 + L2 and pH 3.0 + L2 treatments fungi significantly increased （P ＜ 0.01）. Thus, litter could alleviate the influence of acid rain on soil nutrient content and microbe quantity. ［Ch, 6 fig. 45 ref.］