关键词: 施氮水平, 蚕豆枯萎病, 土壤微生物功能多样性

Abstract: Effects of temperature, moisture and forest succession, as well as the ir interaction on nitrogen mineralization in hillside red soils in mid-subtropi cal region were investigated. The results showed that effects of temperature and succession stage on soil ammonification rate were significant with rate at 12 ℃<24 ℃<36 ℃, and rate in shrub and Masson pine forest being lower than that in evergreen broad-leaved forest (P＜005), while the impact of moisture was not significant. Moisture and succession stage significantly affected the so il nitrification rate, with that of half-saturation being higher than natural a nd saturation moisture levels, and that in Masson pine forest being higher than in shrubs (P＜005), while temperature had no significant impact. The effec ts of temperature, moisture and succession stage on soil net N-mineralization r ate were all significant, with 12 ℃<24 ℃<36 ℃, half-saturation higher than natural and saturation, and shrubs<Masson pine forest<evergreen broad-leaved forest (P＜005). Soil ammonification and net N-mineralization rates incr eased with increasing temperature, while the maximum soil nitrification rate occ urred at medium temperature. Moderate soil moisture would benefit the nitrogen m ineralization process, and forest succession could improve soil nitrogen supply and restrain excessive nitrification.

Key words: nitrogen application rate, faba bean fusarium wilt, soil microbial functional diversity.