烟对稻-烟轮作水稻季不同施氮后效的响应

探讨烤烟对稻-烟轮作水稻季不同施氮后效的响应,为下季烤烟氮肥合理施用提供理论依据。在贵州省遵义市开展稻-烟轮作试验,水稻季设置不同氮素水平(0、90、180和270 kg/hm~2),烤烟季所有处理均不施氮肥,测定烤烟生物性状、生物量、产量、叶片养分含量、叶片品质及收获后供试土壤的养分含量,并计算烤烟的经济效益。结果显示,在施氮0~270 kg/hm~2范围内,水稻季施氮肥越多,烤烟季养分的后效越强,烤烟株高、茎围、最大叶长、最大叶宽、总叶片数和干重均以N270处理为最大,但均低于优质烟标准;烤烟产量N180处理最高(1 193 kg/hm~2),但只有常年产量54%;烤烟产值N90处理最大,为21 234元/hm~2;与种植前相比,烤烟收获后土壤氮素养分含量均有所降低,施氮量增加,土壤中剩余氮素增多,相应烤烟吸收氮素增多,后效明显。本试验研究表明,水稻季施氮90 kg/hm~2,其后效的烤烟产值最高,烤烟生长季应该在充分考虑前茬水稻氮肥后效的基础上进行优化推荐施氮。

Responses of tobacco to N residual effect in different N application in tobacco rice rotation

In order to provide a scientific basis for reasonable application of nitrogen fertilizer in tobacco season, a field experiment was carried out to explore the responses of tobacco to N residual effect in different nitrogen application in tobacco rice rotation. A field experiment was conducted with different nitrogen application rates (0, 90, 180 and 270 kg/hm2) in rice season, and with no nitrogen application in tobacco season. The biological characters, biomass, yield, nutrient content of leaves, leaf quality of tobacco and nutrient content of soil after tobacco harvest were measured, and the economic benefits of tobacco was calculated. Results showed that the more nitrogen application in rice season, the more nitrogen residual effect in tobacco season. The height, stem diameter, maximum leaf length, maximum leaf width, number of leaf of tobacco in N270 treatment were higher than other treatment, but were lower than those of the high quality tobacco standard. The production of N180 was 1 193 kg/hm2, but was only 54% of perennial production. The value of N90 was 21 234 yuan/hm2, higher than that of N180, N270 and N0, respectively. The content of soil nitrogen nutrient were reduced after the tobacco harvest, the higher the amount of N fertilization, the more nitrogen residue in soil and nitrogen uptake of tobacco, and the stronger the residual effect of fertilizer. The conclusion showed that the nitrogen residual effect of tobacco value was higher than other treatments in N90 treatment, the nitrogen recommendation should be considered on the basis of N residual effect of rice in tobacco season.