重庆核桃主要产区土壤养分状况及肥力评价

Soil Nutrient Status and Fertility Evaluation in Major Producing Areas of Walnut,Chongqing

采集重庆核桃主要产区土壤样品,分析土壤养分质量分数及综合肥力情况。结果表明:(1)重庆核桃产区土壤pH值范围为5.57~8.46,少量产区呈微酸性。根据全国第二次土壤普查养分质量分数分级标准,重庆各核桃产区土壤有机质质量分数较低,为5.11~16.22 g/kg。土壤全氮、碱解氮、速效钾质量分数分别为0.69~1.31 g/kg、25.43~120.53、13.50~142.98 mg/kg,总体均处于中下水平。土壤全钾质量分数较高,为18.64~36.89 g/kg。全磷、有效磷质量分数分别为0.47~1.13 g/kg和6.23~42.37 mg/kg,总体达到中上水平。土壤有效Ca、Mg质量分数丰富,分别为551.21~9671.42和21.21~688.25 mg/kg。有效Fe、Mn、Zn、B质量分数处于中等偏下水平,分别为1.94~11.20、1.31~29.03、0.42~1.54、0.21~0.57 mg/kg。有效Cu、Mo质量分数在各产区差异性较大。(2)采用内梅罗综合指数法评价显示,重庆核桃产区土壤综合肥力均为III级,属一般肥力水平,且有机质、氮和钾是限制土壤肥力的主要因子。因此,建议重庆核桃产区施肥以氮肥与钾肥为主,同时配施有机肥以及铁、锰、锌、硼等微肥,以达到培肥土壤和促进核桃生长结果的双重作用。

The soil samples in major producing areas of walnut(Juglansregia L.)in Chongqing were collected to analyse the nutrient content and fertility status,to provide scientific basis for guiding the fertilizing of walnut orchards in Chongqing.Results showed that(1)The soil pH of walnut producing areas in Chongqing were 5.57-8.46,presented neutral or weakly alkaline,which could satisfy the fine growth of walnut trees in Chongqing,except that minor producing areas had slight imbalance.Based on the classification standard of soil nutrients in the second soil investigation of China,the content of soil organic matter in major walnut producing areas were 5.11-16.22 g/kg,all in moderate or below level on the whole.The content of total nitrogen,alkali hydrolysable nitrogen,and available potassium were respectively 0.69-1.31 g/kg,25.43-120.53 mg/kg and 13.50-142.98 mg/kg,all in mid-low or below level on the whole.However,the content of total potassium in soil was high,which was18.64-36.89 g/kg,and the total phosphorus and available phosphorus both reached mid-high or higher level,which were respectively 0.47-1.13 g/kg and 6.23-42.37 mg/kg.The contents of available Ca and Mg in major walnut producing areas both reached mid-high or higher level,respectively 551.21-9671.42 and 21.21-688.25 mg/kg.The contents of available Fe,Mn,Zn and B were all moderate or below level,which were 1.94-11.20,1.31-29.03,0.42-1.54 and 0.21-0.57 mg/kg,respectively.The contents of available Cu and Mo varies greatly from low to high in different producing areas;(2)From the improved Nemerow synthesis index method,the soil comprehensive fertility of major producing areas of walnut in Chongqing were all in III grade,which only reached general fertility level,and soil organic matter,nitrogen,and potassium were main limiting factors of the soil fertility.Accordingly,we suggest that aiming at fertilization in Chongqing walnut orchard,nitrogenous fertilizer and potassium fertilizer should be added more,combined with organic fertilizer and micro-fertilizers(concluding Fe,Mn,Zn and B et al.),in order to fertilize soil and promote the growth and fruiting of walnut in Chongqing.