重庆市山地血橙园不同种植模式土壤理化性质关联分析

研究了重庆市璧山县河边镇血橙核心示范园区的血橙 红薯(Ⅰ)、血橙 花生(Ⅱ)、血橙 玉米(Ⅲ)、血橙 茄子(Ⅳ)、血橙纯林(Ⅴ)5种模式下0~10 cm和10~20 cm土壤理化性质, 并用灰色关联法进行综合分析, 探讨了不同种植模式血橙园减小土壤容重, 增加土壤孔隙, 提高土壤养分含量效果差异的原因。结果表明: 同一种植模式不同土层比较, 土壤容重、非毛管孔隙度、总孔隙度, 土壤有机质、全氮、碱解氮、有效磷、速效钾含量均随土层深度的增加显著减少, 毛管孔隙度、全磷、全钾则在测试土层间含量变化不大。不同种植模式下相同土层土壤容重、孔隙度、土壤的养分含量差异均达到显著水平(P<0.05)或极显著水平(P<0.01), 且相同土层不同种植模式比较, 模式Ⅴ土壤容重最大, 非毛管孔隙、总孔隙度、有机质、全氮、全磷、碱解氮、有效磷、速效钾均最小, 而毛管孔隙度大于模式Ⅱ, 全钾则表现为0~10 cm土层含量略高于模式Ⅱ, 10~20 cm土层含量最低; 各种植模式改善土壤理化性质效果在0~10 cm土层为: 模式Ⅰ>模式Ⅲ>模式Ⅳ>模式Ⅱ>模式Ⅴ, 在10~20 cm土层为: 模式Ⅰ>模式Ⅳ>模式Ⅲ>模式Ⅱ>模式Ⅴ。各模式地表植被生物多样性、地下根系分布、农作物的生物学及生态学特性不同, 是导致各模式改善土壤理化性质效果差异的主要原因。

Correlation analysis of soil physical and chemical properties under different planting patterns of blood orange garden in hilly areas of Chongqing City

Agroforestry, as a form of land use, is an effective technique to preserve mountain ecology and environment. To evaluate the ecological benefits of mountain agroforestry for guiding future land use planning, the physical and chemical properties of the 0 10 cm and 10 20 cm soil layers of agroforestry patterns of blood orange-sweet potato (I), blood orange-peanut (II), blood orange-maize (III), blood orange-eggplant (IV) and pure blood orange (V) were evaluated by using a grey correlation analysis. The paper also comprehensively discussed the differences in effects of different patterns on soil bulk density, soil porosity and soil nutrients contents in blood orange key demonstration area of Hebian Town of Bishan County, Chongqing City. The results suggested that soil bulk density, non-capillary porosity, total porosity, and contents of soil organic matter, total nitrogen, alkali-hydrolysis nitrogen, available phosphorus and available potassium under the same cultivation pattern were significantly lower in 0 10 cm soil layer than those in 10 20 cm soil layer. Also capillary porosity, total phosphorus and total potassium of different soil layers under the same cultivation pattern were not significantly different between two soil layers. Differences in soil bulk density, porosity and soil nutrients contents in the same soil layer among different cultivation patterns were either significant (P < 0.05) or extremely significant (P < 0.01). Soil bulk density was highest and non-capillary porosity, total porosity, and contents of soil organic matter, total nitrogen, total phosphorus, alkali-hydrolysis nitrogen, available phosphorus and available potassium lowest under pure blood orange. However, the total potassium in the 0 10 cm soil layer was slightly higher under pure blood orange than under blood orange-peanut pattern, and those in the 10 20 cm soil layer lowest. Contents of soil organic matter, total nitrogen and alkali-hydrolysis nitrogen of the 0 10 cm soil layer were highest under blood orange-maize pattern. Under blood orange-eggplant pattern, soil organic matter and available potassium contents in the 10 20 cm soil layer were highest. Then under blood-sweet potato pattern, total phosphorus and total potassium contents were highest. Also under blood orange-peanut pattern, available phosphorus content was highest. A comprehensive evaluation of the improvement in soil nutrients of different agroforestry patterns was done using grey correlation analysis. Based on the analysis, the order of improvement in soil nutrients in the 0 10 cm soil layer was blood orange-sweet potato > blood orange-maize > blood orange-eggplant > blood orange-peanut > pure blood orange. It was blood orange-sweet potato > blood orange-eggplant > blood orange-maize > blood orange-peanut > pure blood orange for the 10 20 cm soil layer. Surface vegetation diversity, below-ground root system distribution, and biological and ecological characteristics of each cultivation pattern were the main reasons for the differences in soil physical and chemical properties.