摘要
为了探明翻耕条件下秸秆还田量对土壤生物学特性的影响，制定合理的秸秆还田量，减少环境的污染和保障农业的可持续性发展，通过定位试验进行了0％、33％、67％、100％早稻秸秆覆盖翻耕对次年早稻土壤微生物数量、微生物活度、稻草腐解酶活性、氨化作用强度及硝化作用强度的影响研究。结果表明：在次年早稻生长期内，土壤好气性和嫌气性细菌数量呈现前期迅速提高，中后期快速下降的趋势，真菌和放线菌数量呈现前期迅速下降，中后期缓慢上升的趋势。土壤微生物活度则呈前期上升，中期达到最高点后开始下降，后期又有所回升的趋势。土壤木聚糖酶和纤维素酶活性以分蘖盛期为界点，表现出前期增加、后期下降的特点；土壤脲酶呈现先缓慢下降，再迅速下降，最后再缓慢上升的趋势；而土壤蛋白酶和过氧化氢酶的活性在早稻各个生育期的变化不大。土壤氨化作用强度的变化特点是先下降后上升，在齐稳期达到高峰后又迅速下降；而土壤硝化作用强度则呈现前期快速下降、中期缓慢增加、后期再急剧下降的趋势。土壤微生物数量及活性分析评价发现，在双季稻栽培时，配合水稻专用复混肥一次性施用，以早稻秸秆2500～5000kg·hm^-2翻耕还田较为适宜。
An experiment was conducted to determine the effect of incorporating rice-straw into the soil on microbial and enzyme activity. The soil was treated with 0% , 33% , 67% and 100% rice-straw and microbial quantity, microbial activity and soil rice- straw decomposing enzyme, and ammonification and nitrification of Successive early paddy soil determined. The results show that during early-rice growth period, aerobic and anaerobic bacteria quantity increases rapidly in the early growth stage, but decrease rapidly afterwards. The quantity of fungi and actinomycetes decreases rapidly in the early growth stage, and slowly increases in the middle and later stages. Microbial activity increases at the early stage, reaches the highest peak, followed by a sharp decline at the middle stage, and finally gradually increases during the late stage. Xylanase and cellulase activity increases before maximum tillering stage and decreases after that. Urease activity initially slowly decreases and then drops sharply, but again slightly increases during the late stage. Alterations in protease and catalase activity are not serious in the entire growth period. Ammonification decreases initially, then increases and attains the highest peak at full heading, then decreases rapidly at late growth stage. Nitrification of early paddy soil decreases during the early stage and then gradually increases for while, before a rapid decrease at the late stage. The results show the optimal application of rice-straw to be 2 500 - 5 000 kg·hm^-2 .
出处
《中国生态农业学报》
CAS
CSCD
2008年第2期380-386,共7页
Chinese Journal of Eco-Agriculture
基金
“十五”国家粮食丰产科技工程湖南专项(2004BA520A01)
湖南农业大学后备人才创新团队基金(05TD02)资助
关键词
稻草还田
土壤微生物
土壤酶
微生物活度
氨化作用强度
硝化作用强度
Incorporation of rice-straw into soil, Soil microbe, Soil enzyme, Microbial activity, Ammonification intensity, Nitri- fication intensity
