EM保水剂施用对烤烟的影响及其施用制度的优选研究

摘要

Flue-cured tobacco is an important economic crop in China, with the highest planting area and yield in the world. With a huge capacity to improve financial revenue, flue-cured tobacco production in China’s southwest provinces (e.g., Yunnan, Guizhou, Sichuan) is critical for the national economy. But periodic droughts in tobacco planting zones affect the production of flue-cured tobacco and the normal maturity process. Enhancing studies on drought resistance, water-saving techniques and reasonable regulation of field water supply in flue-cured tobacco production is necessary to guarantee high quality and yield production in arid regions. In this study, MP3005KM water-retention agent, straw, EM activated calcium and EM rejuvenation were used to determine the effect of EM water-retention agent on tobacco growth, yield and quality. The study also used entropy weight coefficient evaluation model and system evaluation indexes to select the optimal application schemes with the most comprehensive benefits. The results showed that different treatments all increased tobacco leaf area of a single plant, especially, straw treatments (T1 and T2) more significantly increased leaf area of a single plant at later growth stage of flue-cured tobacco. The crop growth model simulating the dynamics of LAI showed that T2 (40 g×plant-1 EM activated calcium+300 g×plant-1 straw) and T6 (40 g×plant-1 EM activated calcium+6 g×plant-1 MP3005KM) obtained more larger increasing range. EM water-retention agent treatments increased net photosynthetic rate (Pn) and decreased transpiration rate (Tr), which regulated photosynthetic effects of tobacco leaves at vigorous stages (including maturity stage). Principle component analysis showed that EM water-retention application significantly increased the overall quality of tobacco leaves compared with no EM water-retention agent. Straw treatments had better quality improvement effects, with comprehensive quality indexes 3.25 and 2.76, respectively, for T1 and T2. In terms of high yield, good quality, water-saving potential and fertilizer use efficiency, the 40 g×plant-1 of EM-calcium combined with 4 500 kg×hm-2 of straw system was recommended as the application scheme of EM water-retention agent for flue-cured tobacco. Under this scheme, flue-cured tobacco yield, irrigation water use efficiency and nitrogen use efficiency were 2 433.5 kg×hm-2, 0.608 kg×m-3 and 27.04 kg×kg-1, respectively.%烤烟是我国重要的叶用经济作物，我国是烟草种植面积和烟叶总产量最高的国家，烤烟生产对我国西南诸省(如云、贵、川)国民经济和财政收入水平的提高有重要作用。但烟区出现的阶段性干旱经常影响烤烟的产量及其正常的成熟。因此，加强烤烟节水抗旱技术研究，合理调控烟田水分供应，是确保干旱地区烟叶优质适产的关键。本文分别以MP3005KM保水剂、秸秆、EM活性钙和EM复壮液为主要材料制作EM保水剂，研究了不同 EM 保水剂处理对烤烟生长、产量和品质的影响，并引入熵权系数评价模型，建立评价指标体系，优选综合效益最优的EM保水剂施用制度。结果表明：不同EM保水剂处理均增加了烤烟单株叶面积，秸秆为主要材料的EM保水剂(T1和T2)对烤烟生长中后期叶面积的增长促进作用更明显；表征烤烟叶面积指数(LAI)动态变化的作物生长模型显示， T2(40 g×株-1 EM活性钙+300 g×株-1秸秆)和T6(40 g×株-1 EM活性钙+6 g×株-1 MP3005KM)处理烤烟 LAI 具备较大的增长空间； EM 保水剂明显提高了烤烟旺长期和成熟期的净光合速率(Pn)，同时降低了蒸腾速率(Tr)，调节了烤烟叶片的光合作用。主成分分析显示，与不施保水剂相比， EM保水剂的施用显著提高了烤烟的“综合品质”，秸秆为主要材料的EM保水剂的“提质”效益最优， T1和T2烤烟品质综合主成分值分别达3.25和2.76。综合考虑“高产”、“优质”、“节水”和“节肥”等因素，本研究推荐40 g×株-1 EM活性钙结合4500 kg×hm-2秸秆段作为EM保水剂的施用制度，在该制度下，烤烟产量、灌溉水利用效率和氮肥偏生产力分别为2433.5 kg×hm-2、0.608 kg×m-3和27.04 kg×kg-1。