施用芝麻饼肥对植烟根际土壤酶活性和微生物碳、氮的影响

Effects of sesame cake fertilizer on soil enzyme activities and microbial C and N at rhizosphere of tobacco

采用盆栽试验研究了施用芝麻饼肥对烟草根际土壤酶活性和微生物C、N的影响.结果表明,施用芝麻饼肥可明显提高根际土壤酶活性和土壤微生物C和N含量,芝麻饼肥和化肥配施(CF)与单施化肥(F)相比,根际土壤脂肪酶、转化酶和脲酶活性分别提高了24.85% ～ 60.00%、23.08% ～ 39.46%和4.17% ～ 56.21%; 根际土壤微生物C、N含量分别提高79.88% ～ 97.14%和29.73% ～ 74.96%.表明施用芝麻饼肥土壤生物过程活跃,有利于土壤有机物质的转化和烤烟正常生长所需的营养供应.在烟草不同生育期,根际土壤微生物C和微生物N含量动态变化不同,土壤微生物C含量在现蕾期达到最高值,而土壤微生物N含量高峰出现在团棵期.随着烟草的生长发育土壤微生物N逐渐降低,表明一部分微生物N又被释放出来,以供烟草生长发育需要; 到成熟期明显降低,反映出土壤微生物N在协调土壤N素供应方面的重要作用.适量饼肥与化肥配合施用,有利于平衡烟草N素营养,改善烟叶品质.

It has been proved that rational application of sesame cake fertilizer collaborated with chemical fertilizer could increase the output and quality of tobacco leaves. However, the responses of soil biochemistry properties on the application of sesame cake fertilizer were still not clear. A potted plant experiment was carried out on a loam soil cultivated with tobacco, in order to investigate the effects of sesame cake fertilizer on soil enzyme activities and microbial C and N. Four treatments were applied： no fertilizer （CK）, single application of chemical fertilizer（F）, single application of sesame cake fertilizer（C） and combined application of sesame cake fertilizer with chemical fertilizer treatment （CF, organic N and mineral N respectively accounted for a half of total N ）. The results indicated that the sesame cake fertilizer could promote the enzyme activities and increase microbial C and N contents in soil. Comparing with single application of chemical fertilizer, combined application of sesame cake fertilizer with chemical fertilizer could promote lipase, urease and invertase activities by 24.85 %-60.00 %, 23.08 %-39.46 % and 4.17 %-56.21%, and increase soil microbial C and N contents by 79.88%-97.14% and 29.73%-74.96% respectively. The promotion of enzyme activity was of great advantage to the turnover of organic matter and provision of nutrition to meet the needs of tobacco＇ s regular growth. The dynamic changes of microbial C and N content were different at different growth duration. Microbial C content reached the peak at the budding stage of flue-cured tobacco; however, the peak of microbial N content appeared at the rosette stage.This showed that inorganic N content was higher at the incipient stage of plant growth which resulted from the fixation of soil inorganic N by microorganism. Microorganisms may release N to meet the need of flue-cured tobacco at the late stage and microbial N was reduced markedly at mature stage.Therefore,Microbial N Played an important role in the synchronization of soil N provision with the growth of flue-cured tobacco.We could conclude that the rational application of sesame cake fertilizer mixed with chemical fertilizer could balance nitrogn alimentation,which gave rise to the improvement of the quality of flue-cured tobacco leaves.