广西蔗区土壤肥力特征与评价

[目的]通过分析评价广西甘蔗种植区的土壤肥力状况,为甘蔗科学合理种植及施肥提供理论依据,并进一步完善广西蔗地土壤肥力评价体系.[方法]对采自广西甘蔗种植区3 006个样点的耕层土壤样品进行养分测定,并采用改进的Nemerow肥力综合指数法评价该基地土壤的肥力特征.[结果]试验结果表明,广西蔗区土壤质地粘重,绝大多数土壤偏酸性,平均值为4.94;土壤有效硼缺乏,平均含量为0.24 mg/kg;土壤交换性镁含量偏低,平均值为62.34 mg/kg;有机质含量一般,碱解N、速效P、速效K、有效铜、有效锌、有效锰、有效钙含量总体处于中等水平,但呈现养分区域不平衡现象与高产土壤条件相比仍有较大差距.改进的Nemerow肥力综合指数法评价结果显示,蔗地土壤肥力为Ⅲ级,即低肥力水平,综合肥力指数为0.56.单项肥力指数有效铜,有效锌,交换性镁,速效,有效锰,碱解氮处于贫瘠水平,其他指标处于一般肥力水平或较高肥力水平.[结论]广西甘蔗种植区土壤肥力总体属于较低水平;采用上述综合评价方法,可提高土壤肥力评价的定量化水平和科学性,从而可减少评价过程中主观因素的影响.

Characteristics and Evaluation of Soil Fertility in Sugarcane-producing Areas in Guangxi

[Objective] Soil fertility in Guangxi sugarcane-growing areas was evaluated to provide theoretical reference for sugarcane scientific planting and fertilization and further optimize evaluation system for soil fertility in Guangxi sugarcane-growing areas.[Method] Nutrients of soil samples in 3 006 plots were measured,and fertility characters were evaluated based on the improved Nemerow composite index method.[Result] Soil in Guangxi sugarcane-growing area was sticky and acidic with an average pH value of 4.94.Available B was insufficient with an average content of 0.24 mg/kg.Exchangeable Mg was low with an average content of 62.34 mg/kg.Organic matter content was moderate.The contents of alkali N,rapidly available P,rapidly available K,available Cu,available Zn,available Mn and available Ca were moderate.However,unlike the soil in high-yield areas,there was unbalanced nutrition distribution.According to Nemerow integrated index method,soil fertility in sugarcane-growing areas was grade Ⅲ,namely low fertility.The integrated fertility index was 0.56.Individual fertility indexes including rapid available Cu,rapidly available Zn,exchangeable Mg,available Mn,rapidly available manganese Mn and alkali N were at poor level.Other indexes were at medium or high level.[Conclusion] It could be concluded that soil fertility in Guangxi sugarcane-growing area was generally low.The above-mentioned evaluation method could help to build a quantified and scientific soil fertility evaluation system and reduce the impacts of subjective factors during evaluation process.