秸秆还田与无机改良剂配合对滨海盐渍化土壤特性的影响

为探讨秸秆还田与无机改良剂配合对滨海盐渍土土壤特性的影响，明确其对盐碱土壤的降盐和改土效果，本研究以黄河三角洲中度盐渍土为研究对象，采用土柱试验，研究不同秸秆还田方式及其与无机改良剂配合对土壤盐分和理化性质的影响。结果表明：秸秆覆盖或翻埋还田配施无机改良剂处理促进了盐分的淋洗，增加了淋溶液中总盐含量以及各盐基离子含量；秸秆还田和秸秆还田与无机改良剂配合均可降低土壤盐分含量，其中秸秆还田与无机改良剂配合较秸秆不还田处理淋溶液中盐分含量增加，且0~＜40 cm土层中土壤盐分含量降低，脱盐率高达70.76%~83.94%；在0~＜20 cm土层中，土壤有机质含量增高了10.96%和11.96%，铵态氮含量增加了 23.77% 和 24.01%，土壤容重降低了 10.19% 和 11.53%，0.25~＜2 mm 水稳性团聚体占比增加了 59.38%和 63.95%；在 20~＜40 cm 土层中，土壤有机质含量增高了 21.07% 和 22.15%，铵态氮含量增加了 22.86% 和 27.99%，土壤容重降低了7.20%和8.13%，0.25~＜2 mm水稳性团聚体占比增加了39.54%和32.67%。研究表明，秸秆覆盖+翻埋还田配合无机改良剂处理对滨海盐渍土的降盐、改土效果最优，可降低土壤盐分、提高土壤质量。

Effects of straw returning with inorganic improver on characteristics of coastal saline soil

Effects of straw returning with inorganic improver on the soil properties of coastal saline soils were assessed, and the improvement of saline-alkali soil quality was elucidated. Moderately saline soil originating from the Yellow River Delta was used as the experimental soil. The soil column test was used to study the effects of different straw-returning methods and their combination with inorganic improver on soil salinity and physicochemical properties. Straw mulching or tilling combined with inorganic improver promoted salt leaching and increased the total salt and salt ion contents in the leaching solution. Straw mulching and inorganic improver combined with straw mulching reduced salt content in the soil; the combination of straw and improver resulted in higher salt content in the leaching solution than straw mulching alone and inorganic improver alone. The soil salinity content was decreased in the soil layer from the surface to approximately 40 cm. The desalination rate was as high as 70.76%-83.94%, in soil of 0 cm to ＜20 cm,the soil organic matter increased by 10.96% and 11.96%, ammonium nitrogen increased by 23.77% and 24.01%, soil bulk weight decreased by 10.19% and 11.53%, percentage of water-stable agglomerates measuring 0.25 mm to ＜2 mm increased by 59.38% and 63.95%. In soil of 20 cm to ＜40 cm, the soil organic matter increased by 21.07% and 22.15%, ammonium nitrogen increased by 22.86% and 27.99%, soil bulk weight decreased by 7.20% and 8.13%, percentage of water-stable agglomerates measuring 0.25 mm to ＜2 mm increased by 39.54% and 32.67%. Straw mulching and tilling with the integrated use of inorganic improvers performed was effective for salt reduction and soil modification. The integrated strategy is the optimal modification technology to decrease soil salt and improve soil quality of coastal saline soils.