油茶低产林养分需求和时间配置动态变化研究

Study on the dynamic variation of nutrients in a Camellia oleifera low-yield forest

以常宁油茶低产林为研究对象,分析了油茶低产林树体各器官及土壤养分时间动态变化。结果表明:油茶低产林树体在不同生长期需求的大量元素均为全N、Ca和全K最多,而需求的Mg和全P最少;需求的微量元素均为Mn和Fe最多,Cu和Cd最少;春梢期供应的土壤养分元素是速效N和Mg,夏梢期主要供应的土壤元素是速效K、全N、全P、Fe和有机质,果实成熟期主要供应的土壤养分元素是全K,开花期主要供应的土壤元素是速效P和Ca;不同时间油茶低产林养分需求为春梢期(28.36%)>夏梢期(26.17%)>果实成熟期(22.75%)>开花期(22.73%);土壤养分供应为夏梢期(2999.83±87.04 mg/kg)>果实成熟期(2703.93±292.26 mg/kg)>开花期(2554.60±508.84 mg/kg)>春梢期(2385.88±199.62 mg/kg);油茶低产林在不同生长期需要的养分和土壤供应的养分并不一一对应。研究结果可为油茶低产林的施肥时间配置和养分时间变化提供科学依据,在春梢期多施肥。

We analysed the temporal dynamic variation of nutrients in various organs and the soil in a Camellia oleifera low-yield forest in Changning.The results showed that the total N,Ca,and K had the highest demand during the different growth stages of C.oleifera,while Mg and P had the least.The trace elements that were in demand were Mn,Fe,Cu,and Cd.Available N and Mg were the soil nutrients supplied during the spring growth stage,and available K,total N,total P,Fe,and organic matter were the main soil elements supplied during the summer growth stage.The main soil nutrient element supplied during fructescence was total K,while the main soil elements supplied during florescence were available P and Ca.The nutrient demand of C.oleifera at different times differed:spring growth stage(28.36%)>summer growth stage(26.17%)>fructescence(22.75%)>florescence(22.73%).The soil nutrient supply was as follows:spring growth stage(2999.83±87.04 mg/kg)>summer growth stage(2703.93±292.26 mg/kg)>fructescence(2554.60±508.84 mg/kg)>florescence(2385.88±199.62 mg/kg).The nutrient demand did not correspond with the soil nutrient supply at the different growth stages.The results provide a scientific basis for allocating the time for fertilisation and variations in the nutrient demand and supply for C.oleifera low-yield forest and indicated that fertilisation should be increased in the spring growth stage.