摘要
刺槐根瘤菌侵染主要是在4—8月份,小瘤形成后,瘤体不断增长,具有较高的固氮活性,7月出现死瘤,冬季一部分死亡,留下部分越冬,次年可继续生长,同时又有新瘤形成:去瘤复栽植株,在4—8月很快能再次结瘤,具有很好的再生能力,8月中旬后去瘤复栽者,当年再生根瘤少,主要在次年春再生,与年周期性的根瘤形成期吻合;固氮活性的季节变化是:4月初随着树叶萌发,活性恢复并迅速增高,夏秋季节保持较高水平,效率一般在6—10微摩尔/克·时,冬季活性很低甚至完全丧失活性,秋季日变化是:上午活性较低而递增较快,下午活性较高而有波状起伏,夜间一直保持较高水平,土壤条件对固氮能力有明显影响,中性、微酸性和弱钙质土固氮量较高,强酸性、强钙质土则低,土壤含水率是影响活性的重要因素;固氮明显促进植株生长。
It is mainly from April to August for the locust Rhizobium to infect the plant. After nodulation the nodules kept on growing fine and had higher N2-fixing activity. Their greater part died in winter. After surviving winter the others grew continuously in next year. The plants picked nodules and the replanted plants got a fast renodulation from April to August and showed high power of revivifying nodule. After August renodulation grew few this year until the next spring.Seasonal variation in the N2-fixation activity was observed. Its recommencement in first ten day of april was associated with leaf expansion. The N2 are activity increaced rapidly and attained a higher level in the summer and autumn period, generally 6-10nmol/g.h, however, it was minimized or entirely stopped throughout winter, from the middle ten days of November to the end of March. The daily variation of the activity in the autumn showed that activity was lower in the morning and bacame higher quick, kept up a higher level in the afternoon and night. Soil conditions apparently influenced nitrogen fixation capacity. It was high on the neutral, weak acid and low calcareous soils, but low on stronghly calcareous and strong acid soils.N2-fixing activty was related obviously with soil moisture content. The nitrogen fixation evidently promoted the plant growth.
出处
《生态学报》
CAS
CSCD
北大核心
1991年第3期280-285,共6页
Acta Ecologica Sinica
关键词
刺槐
结瘤
固氮
生态特性
locust, nodulation, nitrogen fixation, soil condition.
