麦秸淹水处理对连作土壤性状和辣椒疫病田间防控效果的影响

Effects of Wheat Straw with Flooding on Soil Properties and Phytophthora Blight Control in Continuous Chili Pepper Cropping Field

采用室内模拟土壤淹水的方法,研究不同麦秸用量、不同淹水时间对辣椒连作土壤理化性状和辣椒疫霉病菌数量的影响以及田间麦秸淹水处理对辣椒生长和辣椒疫病防控效果的影响。通过常规分析和定量PCR分别测定了不同淹水处理期间多种土壤理化指标和辣椒疫霉病菌的数量,调查了麦秸淹水处理后大棚辣椒的长势、产量和辣椒疫病发生率。研究结果表明:与土壤保湿处理相比,不同麦秸用量和不同淹水时间处理均能降低土壤氧化还原电位,提高土壤有机质、速效磷、速效钾、有机酸和总酚酸的含量。常规淹水和麦秸淹水处理均能降低土壤中辣椒疫霉病菌数量,在10 d和14 d两个淹水时间下,秸秆用量为0.25%时抑制效果最强,继续增加秸秆用量对辣椒疫霉病菌的抑制作用降低。辣椒生产大棚的田间淹水试验表明,添加麦秸淹水处理20d可提高土壤中铵态氮、速效磷和速效钾的含量,降低硝态氮的含量,并可以有效防控辣椒疫病,促进辣椒植株的生长并使产量增加12%。

Crop residues may be used to control soil borne plant diseases. In a laboratory experiment, the effects of different rates of wheat straw on soil physical properties and Phytophthora capsici population were studied under different flooding time. The impact of wheat straw with flooding on the growth and yield of chili pepper was carried out in high tunnel fields. Compared to moist soil, applying wheat straw and flooding significantly decreased soil EC but increased organic matter, available phosphorus, available potassium, organic acids and phenolic acid contents. The number of P. capsici was reduced significantly in both flooding only and flooding plus wheat straw in comparison with the moist soil. Application of 0.25% wheat straw with flooding for 10 days or 14 days strongly inhibited the growth of P. capsici. However, such inhibition to P. capsici declined with increasing rates of wheat straw. Field tests showed that flooding for 20 days with wheat straw addition at400 kg/667 m2 not only increased contents of ammonium nitrogen, available phosphorus and available potassium but also effectively reduced disease incidence of chili pepper blight, promoting pepper growth and enhancing chili pepper yield by 12%.