滨海新围滩涂不同改良方式对土壤盐渍化调控效应及其主控因素

土壤盐渍化是制约滨海新围滩涂围垦区土壤质量的最主要因子,严重抑制了作物的生长和产量。试验设置了对照处理(CK)、有机肥(OM)、聚丙烯酰胺+有机肥(PAM+OM)、秸秆覆盖+有机肥(SM+OM)、秸秆深埋+有机肥(BS+OM)和生物菌肥+有机肥(BM+OM)6个处理方式,研究不同改良方式对滨海盐碱地土壤盐渍化的调控效应,明确改良过程中土壤盐渍化程度变异的主控因素。结果表明,表层土壤含盐量、钠吸附比和碱化度随着燕麦生育期的推移逐渐上升,而pH随着燕麦生育期的推移逐渐下降。与CK处理相比,PAM+OM、SM+OM、BS+OM和BM+OM措施能够显著降低0—20cm深度的土壤含盐量、pH、钠吸附比和碱化度。其中,SM+OM措施对土壤含盐量的抑制效果最好,达到68.0%~73.6%;而BM+OM措施对pH、钠吸附比和碱化度的调控效果最佳,分别降低4.5%~8.2%,61.5%~80.8%和55.5%~79.4%。主控因素分析表明环境因子中的土壤容重、土壤含水量和蒸发量对表层土壤盐渍化程度的影响均达到极显著水平(P<0.01),而风速和降水量的影响则达到显著水平(P<0.05)。

Regulatory Effect of Different Amelioration Methods on Soil Salinization and Its Main Control Factors in a Newly Reclaimed Coastal Tidal Land

Soil salinization is the most important factor that restricts the soil quality in the newly coastal reclamation area, which seriously inhibits the growth and yield of crops. Six treatments including control treatment (CK), organic fertilizer (OM), polyacrylamide+organic fertilizer (PAM+OM), straw mulching+organic fertilizer (SM+OM), buried straw+organic fertilizer (BS+OM), and bacterial fertilizer+organic fertilizer (BM+OM) were set up to study the effects of different amelioration on soil salinization in coastal saline-alkali soil, and to identify the main factors controlling the variation of soil salinization degree. The results showed that the salt content, sodium adsorption ratio, and exchangeable sodium percentage of surface soil gradually increased, while the pH decreased gradually with the growth stage of oats. Compared with CK treatment, PAM+OM, SM+OM, BS+OM, and BM+OM treatments could significantly reduce soil salinity, pH, sodium adsorption ratio, and exchangeable sodium percentage at 0-20 cm depth. Among them, SM+OM treatment had the best inhibition effect on soil salinity, reaching 68.0%~73.6%, while BM+OM treatment had the best inhibition effect on pH, sodium adsorption ratio, and exchangeable sodium percentage, which decreased by 4.5%~8.2%, 61.5%~80.8%, and 55.5%~79.4%, respectively. The analysis of key influencing factors showed that the effects of soil bulk density, soil water content, and evaporation on the salinization degree of surface soil reached an extremely significant level (P<0.01), while the effects of wind speed and precipitation reached a significant level (P<0.05).