不同改良剂对盐渍土西瓜耐盐性和生长的影响

为缓解土壤盐渍化对西瓜的胁迫，以“纯品8424”西瓜为试材进行田间试验，设置单施化肥(CF)、CF+胡敏酸钙(CFR1)、CF+水溶性硅肥(CFR2)、CF+鼠李糖脂(CFR3)、CF+胡敏酸钙+水溶性硅肥(CFR4)和CF+胡敏酸钙+水溶性硅肥+鼠李糖脂(CFR5)6个处理，研究了不同改良剂单独或配合施用对土壤pH、盐基离子、西瓜耐盐性及生长的影响，并采用隶属函数法对西瓜耐盐性指标进行综合评价，筛选出适宜盐渍土西瓜生长的最佳改良剂及其组合。结果表明：施用改良剂降低了土壤pH，其中CFR3、CFR4、CFR5的效果显著，较CF分别降低了0.3、0.4、0.4(P<0.05)；改良剂单施或混施增加了土壤Ca²⁺、K⁺、Mg²⁺含量，CFR1、CFR4、CFR5显著降低了土壤Na⁺含量，单一改良剂处理中以CFR1效果最好，与CF相比，土壤Na⁺含量降低了6.56%，土壤K⁺、Ca²⁺、Mg²⁺的含量则分别增加了...

Effects of different amendments on salt tolerance and growth of watermelon in saline soils

To alleviate the stress of soil salinization on watermelon,"Pure 8424"watermelon was used as the experimental material in the field trial. Six treatments were designed as follows:chemical fertilizer only(CF), CF + calcium huminate(CFR1), CF + water-soluble silicon fertilizer(CFR2), CF + rhamnolipid(CFR3), CF + calcium huminate + water-soluble silicon fertilizer(CFR4)and CF + calcium huminate + water-soluble silicon fertilizer + rhamnolipid(CFR5). The effects of different amendments alone and in combination on soil pH, salt-based ions, watermelon salt tolerance, and growth were examined. Furthermore, a comprehensive evaluation of watermelon salt tolerance indexes was performed using the membership function method to screen for the best amendments and their combinations suitable for watermelon growth in saline soils. The following results were obtained. Application of the amendments reduced soil pH; the CFR3, CFR4, CFR5 treatments effectively decreased pH by 0.3, 0.4, and 0.4, respectively, compared with the CF treatment(P<0.05). The single or mixed application of amendments increased soil Ca²⁺, K⁺, and Mg²⁺ concentrations. The CFR1, CFR4, and CFR5 treatments significantly reduced soil Na⁺ concentration. Compared with the CF treatment, the application of CFR1 treatment, which had the most pronounced effect among the single amendment treatments, decreased soil Na⁺ concentration by 6.56% and increased K⁺, Ca²⁺, and Mg²⁺ concentrations by 16.13%, 31.96%, and 20.85%, respectively, in each case reaching a significance level of P<0.05. Furthermore, the single or mixed application of amendments promoted watermelon photosynthesis, quality, and yield. Compared with the CF treatment, the net photosynthetic rate, soluble solids content, and yield increased by 15.22%-43.76%, 8.57%-20.45%, and 14.41%-40.83%, respectively. The CFR2 treatment had the most significant effect among the single amendment treatments. The application of amendments significantly reduced the Na⁺ concentration in watermelon plants, which enhanced the salt tolerance of watermelons. Compared with the CF treatment, the malondialdehyde content and O₂^-·production rate in leaves decreased by 12.14%-30.97% and 18.97%-47.59%, respectively, while the peroxidase activity and proline content increased by 31.72%-74.73% and 26.56%-48.95%, respectively. Calcium huminate, water-soluble silicon fertilizer, and rhamnolipid applied alone or in combination not only alleviated the damage caused by soil salinity stress in watermelon plants to a certain extent, but also significantly enhanced the salt tolerance of watermelon and promoted its growth. The calcium huminate treatment had the best effect among the single amendment treatments. Compared with the single amendment treatments, the combined application of three amendments further improved the salt tolerance of watermelon and achieved the best comprehensive effect overall.