应用PGPR菌肥减少烤烟生产化肥的施用量

利用从烤烟根际筛选的抗生菌、固氮菌、解磷菌和解钾菌菌株制成PGPR菌肥,进行田间完全区组随机试验,研究其在减施化肥的条件下对烤烟产量质量的影响。试验地土壤类型为黄棕壤,种植烤烟品种为云烟89,菌肥施用量30 kg hm-2,于烤烟移栽时溶于生根水中一起施入。共设4个处理,分别是(1)常规施肥同时施用PGPR菌肥;(2)NPK肥为常规施肥的80%同时施用PGPR菌肥;(3)常规施肥;(4)NPK肥为常规施肥的80%。结果表明,施用菌肥的二处理与未施用菌肥的二处理相比,施用菌肥不同生长期烤烟根际放线菌的数量显著降低17%～27%(p<0.05),根际微生物生物量碳含量提高3%～16%,现蕾期根际解磷菌的数量显著提高24%(p<0.05),并可提高烤烟的抗病性,烤后烟外观质量好。处理(2)与处理(4)比较,现蕾期烤烟根际氮、钾、铜、锌、硼和铁6种元素的有效性提高4.46%～28.87%,而磷、钙、镁和锰4种矿质元素的有效性降低2.63%～30.19%,烤烟产量和净产值分别提高7.53%和30.05%。处理(2)与处理(3)比较,烤烟产量和净产值分别提高4.52%和24.68%。使用PGPR菌肥可适当减少化肥用量,为可持续生产优质、无公害烟叶的有效途径之一。

Effect of application of PGPR on chemical fertilizer application rate for flue-cued tobacco

PGPR bacterial manure is becoming more and more common in crop and vegetable production, but it has not been specialized enough to be used on flue-cured tobacco. In this study, The PGPR bacterial manure was prepared by antibiotic bacterium, nitrogen fixation bacterium, dissolving phosphorite bacterium, and dissolving potassium bacterium, which all were isolated from flue-cured tobacco rhizosphere. The soil type of experiment field was yellow brown soil. The flue-cured tobacco variety cultivated was Yuanyan 89. The PGPR bacterial manure was employed at a dose of 30 kg hm-2 when flue-cured tobacco was transplanted to plots. Four treatments were applied viz., 100% NPK of the recommended doses for tobacco + PGPR bacterial manure (100% NPK + PGPR), 80% NPK of the recommended doses for tobacco + PGPR bacterial manure (80% NPK + PGPR), 100% NPK of the recommended doses for tobacco (100% NPK), and 80% NPK of the recommended doses for tobacco (80% NPK). The results released that, the amount of actinomyces in tobacco rhizosphere of PGPR applied treatments was significantly reduced while the content of microbial biomass carbon increased during the whole growth period, the amount of dissolving phosphorite bacteria at budding stage significantly increased; the quality of cured leaves was better, compared to the non-PGPR controls. The percent validities of N, K, Cu, Zn, B, and Fe in tobacco rhizosphere at budding stage of 80% NPK + PGPR increased from 4.46% to 28.87%, but the percent validities of P, Ca, Mg, and Mn decreased from 2.63% to 30.19%; the yield and net production value of cured leaves were increased by 7.53% and 30.05%%, compared to 80% NPK. Also the yield and net production value of cured leaves of 80% NPK + PGPR increased by 4.52% and 24.68% compared with 100% NPK. The results suggest that PGPR bacterial manure allows reduced application rates of chemical fertilizers and increased yield and quality of flue-cured tobacco.