土壤生物消毒对土壤改良、青枯菌抑菌及番茄生长的影响

针对目前作物集约化和单一化种植所造成的土壤连作障碍以及退化问题,通过土壤培养试验和田间试验研究了土壤生物消毒(土壤中添加2%的米糠、麦麸、茶籽麸后覆盖塑料薄膜,以不添加物料不覆盖为对照)对土壤特性、防控青枯病、番茄生长及产量和品质的影响,以期为土壤生物消毒法的理论研究和实践应用提供参考。结果表明,与对照相比,不同土壤生物消毒处理均能显著提高土壤温度、pH和电导率,降低土壤Eh,显著减少土壤中97.27%~99.14%青枯菌数量;同时显著增加土壤有机质、全氮、碱解氮和速效钾含量,而对全磷和全钾影响不显著。不同土壤生物消毒处理能显著降低青枯病发病率29.41%~42.65%。此外,土壤生物消毒显著提高番茄叶片F_v/F_m,对光合参数净光合速率、蒸腾速率、气孔导度、胞间CO_2浓度影响不显著;显著增加番茄株高(16.90%~29.15%)和产量(41.41%~56.25%);果实糖酸比、可溶性糖含量也有所增加。以添加麦麸的生物消毒在提高pH、防控青枯病及提高产量的效果最佳。综合来看,作为一种非化学土壤消毒方法,土壤生物消毒在改良土壤、防控土传病害青枯病和促进番茄生长方面表现出较好的优势,值得推广应用。

Effect of biological disinfestation on soil improvement, Ralstonia solanacearum suppression and tomato growth

Soil-borne diseases and soil degradation caused by continuous cropping or monoculture restrain the sustainable develop-ment of agriculture. Chemical soil fumigation is the most popular method used to control soil-borne diseases in terms of cost and efficacy, but its negative impact on the environment raises a significant concern. Biological soil disinfestation (adding organic mate-rials in soil and mulching for certain time, BSD) is widely used as alternative improvement of degraded soils and in preventing the occurrence of soil-borne diseases. To solve the problems associated with continuous cropping and the soil degradation caused by the intensification of monoculture, the effects of BSD on soil properties, bacterial wilt control and tomato growth were determined in soil incubation and field experiments. There were four treatments in the experiment — the control (CK), BSD with 2% rice bran, wheat bran and tea seed bran. The results showed that different BSD treatments had no significant effect on soil total P and K content, but significantly increased soil temperature, pH, electric conductivity and contents of organic matter, total N, available N and available K. Contrarily BSD treatments significantly reduced soil Eh and the amount of Ralstonia solanacearum in the soil by 97.27%–99.14%. BSD treatments reduced the incidence of bacterial wilt by 29.41%–42.65%, which in turn enhanced tomato plant resistance against the disease. In addition, BSD significantly increased chlorophyll fluorescence parameter Fv/Fm of tomato leaves, but it had no significant effect on net photosynthetic rate, transpiration rate, stomatal conductance and intercellular CO2 concentration. BSD treatments increased tomato yield by 41.41%–56.25%, and the ratio of sugar to acid and soluble sugar content of tomato fruits. Among different organic mate-rials, BSD with wheat bran had the best effect in terms of soil improvement, yield increase and bacterial wilt suppression. In summary, the potential of BSD was promising for the improvement of soil, prevention and control of soil-borne bacterial wilt disease and promo-tion of tomato growth. Thus BSD was critical for a non-chemical disinfection of cultivated soils.