桂西北板栗园区土壤养分含量分析及评价

Analysis and evaluation of soil nutrient content in chestnut orchards in Northwest Guangxi

【目的】分析和评价桂西北板栗园区土壤养分状况,为桂西北地区板栗的科学施肥和管护及促进板栗产业健康发展提供科学依据。【方法】选取桂西北地区4个县6个板栗园区,采用常规方法测定土壤pH及有机质、大量元素、交换性钙和镁含量,分析各园区的土壤肥力差异,与全国第二次土壤普查的土壤养分分级标准进行比对评价,并对板栗园区的pH和土壤养分含量进行相关分析。【结果】桂西北6个板栗园区的土壤pH为4.31~6.71,总体上偏酸性,其中,金城江区和东兰县板栗园区的土壤pH在4.50以下,达强酸水平;土壤有机质含量为6.63~57.92 g/kg,各园区间差异明显,其中,金城江区和南丹县板栗园区的土壤有机质水平在中等以上,而东兰县和天峨县板栗园区土壤有机质含量缺乏;土壤全氮含量为0.54~2.97 g/kg,碱解氮含量为51.66~335.75 mg/kg,其中,大部分板栗园区的土壤全氮含量达中等以上水平,天峨县-1园区和东兰县2个园区的碱解氮含量处于缺乏水平,而天峨县-2园区和金城江区园区表层土的全氮和碱解氮含量与下层土差异较明显;各板栗园区的土壤磷、钾、钙和镁元素普遍缺乏,其中,全磷含量为0.13~0.73 g/kg,有效磷含量为1.03~15.76 mg/kg,全钾含量为4.18~19.98 g/kg,速效钾含量为37.97~134.90 mg/kg,交换性钙含量为54.58~423.65 mg/kg,交换性镁含量为3.35~28.62 mg/kg。相关分析结果表明,板栗园区土壤pH与速效钾含量呈极显著正相关(P<0.01,下同),与交换性钙含量呈显著正相关(P<0.05),有机质含量与全氮、碱解氮、全磷、有效磷、速效钾和交换性钙含量呈极显著正相关。【结论】桂西北地区板栗园区的土壤养分及其有效性受土壤有机质含量影响明显,土壤磷和钾元素普遍缺乏,因此,其施肥应以有机肥为主,合理补充磷肥和钾肥并提高其有效性。

【Objective】The study aimed to analyze and evaluate soil nutrient of chestnut orchards in Northwest Guangxi,so as to provide scientific basis for scientific fertilization,management and protection of chestnut.【Method】Soil pH,content of organic matter,major element and exchangeable calcium and magnesium were determined by conventional methods in 6 chestnut orchards in 4 counties in Northwest Guangxi.Soil fertility difference in orchards was analyzed,compared and evaluated with soil nutrient classification standard of the second national soil survey.Correlation analysis of pH soil nutrient content in chestnut orchards was conducted.【Result】Soil pH of 6 chestnut orchards in 4 counties in Northwest Guangxi was generally acidic and ranged from 4.31-6.71.In chestnut orchards of Jinchengjiang and Donglan,the soil pH was below 4.50,reaching the level of strong acid.Soil organic matter content ranged from 6.63-57.92 g/kg with significant difference in orchards,and soil organic matter in Jingchengjiang and Nandan orchards was above medium,but soil organic matter in Donglan and Tiane orchards was insufficient.Total nitrogen content ranged from 0.54-2.97 g/kg and the alkali-hydrolyzed nitrogen content ranged from 51.66-335.75 mg/kg.Total nitrogen content of soil in most chestnut orchards were above the medium.Alkali-hydrolyzed nitrogen content was insufficient in Tiane-1 and Donglan orchards.Total nitrogen content and alkali-hydrolyzed nitrogen content showed great difference in different soil layers in Tiane-1 and Jingchengjiang orchards.Phosphorus,potassium,calcium and magnesium content in soil were generally lacking in all the chestnut orchards.Total phosphorus content ranged from 0.13-0.73 g/kg.Available phosphorus content ranged from 1.03-15.76 mg/kg.Total potassium content ranged from 4.18-19.98 g/kg.Available potassium content ranged from 37.97-134.90 mg/kg.Exchangeable calcium content ranges from 54.58-423.65 mg/kg and exchangeable magnesium content ranged from 3.35-28.62 mg/kg.Correlation analysis showed that,soil pH was extremely significantly positively correlated(P<0.01)with available potassium content and significantly positively correlated(P<0.05)with exchangeable calcium content.Organic matter content was significantly positively correlated with content of total nitrogen,alkali-hydrolyzed nitrogen,total phosphorus,available phosphorus,available potassium and exchangeable calcium.【Conclusion】In chestnut orchards of Northwest Guangxi,organic fertilizer can be used as the main fertilizer to improve soil fertility because organic matter is the source of maintaining soil fertility.Phosphorus and potassium fertilizers are reasonably supplemented ande availability was improved to solve the problem of lack of phosphorus and potassium.