功能性盐土改良肥对河西走廊草甸盐土的改土效应

目的]解决河西走廊盐土存在的"旱、涝、盐、瘦"等疑难问题,为改良河西走廊盐土提供理论依据。方法]采用酸碱中和原理、离子交换原理、土壤结构改良方法,将自主研发的盐碱调控剂、有机活性肥和甘草专用肥按比例合成功能性盐土改良肥,进行田间验证试验,以便对功能性盐土改良肥的改土效应作出科学的评价。结果]功能性盐土改良肥最佳配方组合为:盐碱调控剂∶有机活性肥∶甘草专用肥为0.072 4∶0.905 1∶0.022 5。功能性盐土改良肥施用量与草甸盐土总孔隙度、团聚体、持水量、阳离子交换能力(CEC)、有机质、速效氮磷钾、甘草农艺性状和根鲜重呈显著正相关关系,与容重、pH值和全盐含量呈显著的负相关关系。功能性盐土改良肥最佳施用量为24.95t/hm2,甘草鲜根理论产量(y)为13.45t/hm2。不同种类盐碱土改良剂对草甸盐土容重、pH值、全盐和真菌由大到小的变化顺序依次为:对照沃丰隆盐碱土改良剂抗盐丰盐碱土改良剂功能性盐土改良肥;总孔隙度、团聚体、细菌、放线菌和酶活性由大到小的变化顺序依次为:功能性盐土改良肥抗盐丰盐碱土改良剂沃丰隆盐碱土改良剂对照。施用功能性盐土改良肥与对照比较,容重、pH值、全盐和真菌分别降低13.38%,7.91%,39.82%和55.56%;总孔隙度、团聚体和甘草根鲜重增加15.42%,56.36%和21.62%;细菌、放线菌、蔗糖酶、脲酶、磷酸酶和多酚氧化酶分别增加60.26%,84.62%,65.23%,79.52%,68.42%和69.35%。结论]在甘肃省河西走廊草甸盐土上施用功能性盐土改良肥,可以有效改善草甸盐土理化性质和生物学性质,提高土壤酶活性和持水量。

Effect of Functional Solonchak Improvement Fertilizer on Saline Soil Improvement in Meadow of Hexi Corridor

Objective] To solve problems of drought, waterlogging, salination and infertility in salt soil and provide theoretical basis for the improvement of the saline soil in Hexi Corridor.Method] Based on the principle of acid and alkali neutralization, ion exchange and the soil structure improvement method, we mixed in proportion of self-developed saline control agent, organic fertilizer and special fertilizer for liquorice, and carried out the field test experiments, evaluated the effect of mixed fertilizer on saline soil improvement.Results] The fertilizer formula with the best functional improvement to saline soil was in the weight ratio:0.072 4:0.905 1:0.022 5 for salinity control agent, organic fertilizer, and special fertilizer for liquorice, respectively. The application amount of the functional improvement fertilizer was significantly and positively related to the total porosity of the meadow solonchak, the aggregate, water holding capacities, cation exchange capacity(CEC), organic matters, available NPK, licorice agronomic characters and the fresh weight of root and were negatively related to the bulk density, pH value and the salt content. The best application amount was 24.95 t/hm², the theoretical yield of the licorice fresh root(y) was 13.45 t/hm². The effect of different saline soil conditioners on bulk density, pH value, total salt and fungal changed as control > Wofenglong saline soil improver > salt abundant saline soil improvement fertilizer > functional improvement fertilizer. The effects on the total porosity, the aggregate, bacteria, actinomyces and enzyme activity changes as follows:functional improvement fertilizer > salt abundant saline soil improver > Wofenglong saline soil improver > control. Compared with the control, the functional improvement fertilizer reduced bulk density, pH value, total salt and fungi respectively by 13.38%, 7.91%, 39.82% and 55.56%, and increased the total porosity, the aggregate and liquorice root fresh weight respectively by 15.42%, 56.36% and 21.62%. Bacteria, actinomyces, sucrase, urease, phosphatase and polyphenol oxidase increased by 60.26%, 84.62%, 65.23%, 79.52%, 68.42% and 69.35%, respectively.Conclusion] The application of functional improvement fertilizer in the meadow solonchak could effectively improve the physical, chemical and biological properties, and increase the soil enzyme activity and the water holding capacity of the meadow solonchak on the Hexi Corridor in Gansu Province.