油茶叶片营养诊断分析样品适宜采集期研究

Appropriate sampling periods for leaf nutrient diagnosis in Camellia oleifera

为了确定油茶叶片营养诊断分析样品的适宜采集期,采用定点定期连续叶片样品采集方法,测定并比较分析了油茶叶片中的N、P、K、Ca和Mg养分含量的动态变化特征。结果表明:油茶叶片中的N、P、K素含量随其年生长发育进程呈"升高—下降—升高"的趋势,Ca素含量的变化特点是先降低后升高,Mg素含量的变化特点则为先升高后下降。油茶叶片中养分元素含量在6月和8月间的数值变化较小,6～8月可为N素养分测定的适宜采样期;6、8和10月P素变化相对平缓,此时为P养分测定的适宜采样期;K、Ca和Mg养分测定以8月采样为宜。综合分析结果表明,以油茶叶片营养诊断分析为目的的样品适宜采集期为6～8月。

In order to find out the appropriate sampling period for leaves nutrient diagnosis of Camellia oleifera, the dynamic changes of N, P, K, Ca and Mg contents in leaves were determined and analyzed by continuously collecting leaves at fixed location and data. The results show that the N, P, K contents in leaves present the trend of up-down- up with the annual growing processes, change trend of Ca content is down-up, but that of Mg content is up-down. The content of N element in leaves change little from June to August, so the stage is the best sampling period for analyzing N content. Change of P content is relatively smooth in June, August and October, so the stage is the best sampling period for analyzing P content. That for analyzing K, Ca and Mg contents is August. Therefore, the appropriate sampling period for leaf nutrient diagnosis in Camellia oleifera is from June to August.