黄河下游引黄灌区弃土区不同土地利用方式改良土壤功能评价

目的]探讨黄河下游引黄灌区弃土区不同土地利用方式对土壤改良的影响,为该区集中弃土区水土保持生态建设中植被恢复模式的构建提供科学依据和技术参考。方法]以山东省滨州市小开河引黄灌区的刺槐纯林、杨树+花生农林间作和大豆农田为研究对象,测定分析不同土地利用方式下的土壤抗侵蚀能力、土壤蓄水性能及土壤养分含量等指标。采用模糊数学隶属函数法对3种土地利用方式的改良土壤功能进行综合评价。结果]3种土地利用方式可显著增强土壤抗蚀性、改善土壤物理结构、增强土壤蓄水性能和土壤养分。土壤抗蚀能力依次表现为:杨树+花生农林间作大豆农田刺槐纯林裸地。大豆农田改善土壤物理性状能力优于刺槐纯林和农林间作;土壤蓄水能力表现为:大豆农田刺槐纯林农林间作裸地;在增强土壤渗透、减少地表径流方面,农林间作最好,刺槐纯林次之,大豆农田最差。土壤有机质、速效氮和速效磷含量均表现为:大豆农田农林间作刺槐纯林裸地,而土壤速效钾含量表现为:刺槐纯林大豆农田农林间作裸地。结论]引黄灌区弃土区改良土壤功能强弱综合评价为:大豆农田杨树+花生农林间作刺槐纯林。建议在该区域水土流失治理的土地利用方式选择上优先采用大豆农田,其次为农林间作。

Evaluation of Soil Improvement Resulted from Land Use Type in Post-irrigation Spoil Area of Lower Reaches of Yellow River

Objective] Soil improvements resulted from different land use types were determined in a post-irrigation spoil area of the lower reaches of the Yellow River in order to provide scientific reference for soil & water conservation and vegetation restoration. Methods] Three land use types as Robinia forest, poplar+peanut intercropped farmland and soybean farmland were selected in Xiaokaihe irrigation area of the Yellow River in Binzhou City. Anti-erosion ability, water storage capacity and nutrient content of the soils were measured. The functional soil improvements were comprehensively evaluated using membership function in fuzzy mathematics method. Results] Obvious improvements of soil anti-erosion, physical structure, water storage capacity and nutrients were observed. The rank of soil anti-erosion ability was: tree-crop intercropping of poplar+peanut > soybean farmland > Robinia pure forest > bare land. Soybean farmland performed better in improving soil physical structure than Robinia pure forest and tree-crop intercropping did. Soil water storage ability ranked as: soybean farmland > Robinia pure forest > tree-crop intercropping > bare land. For improving soil infiltration and reducing surface runoff, tree-crop intercropping performed the best, followed by Robinia pure forest, and soybean farmland behaved the worst. In respect of the improvements of soil organic matter, available nitrogen and available phosphorus content, they performed as soybean farmland > tree-crop intercropping > Robinia pure forest > bare land; In terms of soil available K improvement, they ranked as: Robinia pure forest > soybean farmland > tree-crop intercropping > bare land. Conclusion] Comprehensive evaluation of the three land use types on improving soil function in post-irrigation spoil area of the lower reaches of the Yellow River showed as soybean farmland > tree-crop intercropping of poplar+peanut > Robinia pure forest. Therefore, soybean farmland is suggested as first choice for the control of soil and water loss in this area, tree-crop intercropping type is also in the list.