杜仲树体矿质元素分布特点与需肥规律

Nutrient Distribution and Uptake Characteristics in Eucommia ulmoides Oliv. Plant

本文对杜仲地上部不同组织中养分含量和养分携出量 ,杜仲对养分的吸收比例 ,杜仲年高生长和地径生长节律等进行了研究 ,并根据杜仲养分吸收特点提出了基本肥料施用比例。结果表明 ,杜仲生长期间吸收的养分主要储存于叶子和皮中 ,木质部数量较少 ;皮和叶的利用将使养分大量损失 ,应通过施肥加以补充。杜仲对氮磷钾 (N∶P2 O5∶K2 O)养分的相对吸收比例为 1∶0 .3∶1.6 ,考虑氮磷钾肥料养分的利用率后 ,提出适于杜仲施肥的氮磷钾养分基本比例为N∶P2 O5∶K2 O =1∶0 .6∶0 .9。实践中应用时 ,可根据当地土壤供应不同养分的状况 ,对这一比例进行适当的调整。陕南杜仲的旺盛生长期在 4 - 7月间 ,施肥应在杜仲生长高峰前的早春进行 。

The nutrient uptake characteristics and the growth of Eucommia ulmoides in the south part of Shaanxi were studied. The results showed that the nutrients uptaken by E. ulmoides mainly existed in the leaves and bark, and there was only a limited amount of nutrient stored in the xylem. Therefore, harvesting the leaves and bark in production will remove a lot of nutrients from the forests. It is essential to add the fertilizers to compensate the nutrients removed. The uptake ratios of N∶P_2O_5∶K_2O by E. ulmoides was 1∶0.3∶1.6. Considering the recovery of the fertilizers, it is considered that the nutrients added for E. ulmoides is N∶P_2O_5∶K_2O = 1∶0.6∶0.9. And the vigorous growth period of E. ulmoides was from April to July, it indicated that the appropriate time to apply the fertilizers for this tree was in early spring, and not later than the end of April to meet the nutrient need of the tree.