不同树龄的紫鹃茶树营养元素变化规律研究

Change Regularity of Nutrient Element in Different Ages of Tea Tree Zijuan

以2、3、6、12龄期的紫鹃茶树为材料,对不同龄期紫鹃茶树地上部分的生物量、树冠不同层次枝叶以及茶树修剪物、采摘新梢和落叶中N、P、K、Ca、Mg等5种元素养分浓度的变化进行了研究。结果表明:在不同的生长发育阶段,紫鹃茶树地上部分的生物量随着树龄的增长而增加,树冠不同层次枝叶中N、P、K、Ca、Mg养分浓度分配从高到低均表现为上层(1～10 cm)>中层(10～20cm)>下层(20 cm以下),需求量趋势为N>K>Ca>Mg>P;各营养元素养分浓度变化趋势不同,落叶中N、P、K、Ca、Mg养分浓度在2龄期至12龄期随树龄增长呈现出先增大后减少的趋势,在6龄期时最大;修剪物中N养分浓度在2龄期至6龄期随树龄增长表现为先减少后增大的趋势,到12龄期又减少,P、K、Ca养分浓度变化趋势与落叶中的一致,Mg养分浓度在2龄期至12龄期随树龄增长而增大;茶树新梢中N、P、K、Ca、Mg养分浓度随树龄变化不明显。

Taking tea trees(Zijuan) respectively aged 2,3,6 and 12 as experiment materials,the changes of overground part biomass and contents of five nutrient elements(N,P,K,Ca and Mg) in different levels of branch leaf in tree crown,in pruning of tree tea,in young shoots and in fallen leaves were studied.The results showed that in each growth period,the overground part biomass increased with increasing wood-age.The concentration of nutrient elements in different levels of branch leaves in tree crown from high to low showed a order of upper level(1-10 cm)>middle level(10-20cm)>lower level(below 20 cm),and the demand trend showed a order of N>K>Ca>Mg>P.The change trend of each nutritional component concentration was different,in which the concentrations of N,P,K,Ca and Mg in fallen leaf showed a trend of increased first and then decreased with increasing tree age in period of 2-12 years old,and reached the maximum in period of six years old;the concentration of N in pruning showed a trend of decreased first and then increased with increasing wood-age in period of 2-6 years old,and then decreased in period of 12 years old,but the concentration of Mg in pruning increased with increasing wood-age in period of 2-12 years old;moreover,the concentrations of P,K and Ca in pruning showed the same trend with those in fallen leaf.There were no obvious changes in concentrations of N,P,K,Ca and Mg in new shoots of tea tree with increasing wood-age.