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田间试验研究了不同时期烤烟根际各土层土壤酶活性变化规律及其不同施氮量对烟叶品质的影响。结果表明:0~20 cm土层范围内,施氮可以提高圆顶期、采烤期及采烤结束后土壤脲酶、转化酶的活性,但当施氮量超过52.5 kg hm-2时,脲酶、转化酶的活性反而降低;土壤蛋白酶活性均在37.5 kg hm-2处理达到最大值,且随着施氮量的增多大都呈现降低的趋势。20~80 cm土层范围内,土壤脲酶、转化酶、蛋白酶活性变化规律并不一致。对于烤后烟叶,施氮量为52.5 kg hm-2的烟叶,糖碱比、氮碱比、钾氯比均比较适宜,化学成分较为协调,燃烧性较好,有利于优质烟叶品质的形成。说明在该地区的试验条件下,水稻土种植烤烟最适宜的施氮量为52.5 kg hm-2。
Field experiments were conducted to study the changes of soil enzyme activities and the effects of nitrogen application rates on the quality of tobacco leaves in different rhizosphere soil layers. The results showed that in the range of 0-20 cm soil layer, nitrogen application could improve soil urease and invertase activities after domestication, harvesting and harvesting, but when nitrogen application exceeded 52.5 kg hm-2, , While the activity of invertase decreased. Soil protease activity reached the maximum at 37.5 kg hm-2 treatment, and most of them showed a decreasing trend with the increase of nitrogen application rate. The changes of urease, invertase and protease activities in 20-80 cm soil layer were not consistent. For the cured tobacco leaves, the tobacco leaves with 52.5 kg / ha nitrogen application rate were all suitable, the ratio of nicotine to base, the ratio of nitrogen to base and the ratio of potassium to chlorine were more suitable. The chemical composition was more harmonious and the flammability was better. This indicates that under the experimental conditions in this area, the most suitable nitrogen application rate for planting tobacco in paddy soil is 52.5 kg hm-2.