底部渗灌对华北落叶松容器苗水肥利用状况及生长、光合特性的影响

Effect of Sub-irrigation with Different Water and Fertilizer Supplies on Growth,Photosynthetic Characteristics and Water-use Efficiency of Containerized Larix principis-rupprechtii Mayr Seedlings

以华北落叶松播种容器苗为研究对象,采用完全随机区组设计,设5个灌水梯度、3个施肥量,共15个水肥处理,探讨不同水肥条件与苗木质量及光合特性间的关系,以期找出华北落叶松容器苗底部渗灌的最佳灌水梯度及缓释肥量。结果表明：与上方灌溉相比,底部渗灌节水68%,苗高提高了6.1%-14.6%;苗木生物量、净光合速率、水分利用效率及叶绿素质量分数随灌水梯度及施肥量的增大呈先增加后降低的趋势;底部渗灌条件下,华北落叶松当年生容器苗最佳水肥组合为75%灌水梯度、施氮量100 mg·株^-1,此处理下苗木水分利用效率、净光合速率及总叶绿素质量分数达到最大,分别为0.89 g·L^-1、10.37μmol·m^-2·s^-1及1.85 mg·g^-1,平均苗高为23.73 cm、地径为3.03 mm、总生物量为0.68 g·株^-1,比上方灌溉处理分别提高了19.42%、7.44%、15.25%。

We studied the effect of sub-irrigation with different water and fertilizer supplies on growth , photosynthetic characteris-tics and water-use efficiency of containerized Larix principis-rupprechtii Mayr seedlings by setting five irrigation gradients and three fertilization concentration .The seedlings under sub-irrigation method saved 68% of water compared with overhead irrigation method .Watering with 75% of water content and fertilizing with 100 mg of nitrogen per plant provided by slow re-lease fertilizer （ N∶P ∶K=13 ∶13 ∶13） improved the development of containerized L.principis-rupprechtii Mayr seed-lings.WUE, Pn and chlorophyll content in this watering and fertilizing pattern reached maximum value, they were 0.89 g· L^-1, 10.37μmol· m^-2 · s^-1 and 1.85 mg· g^-1, respectively.The average seedling height , root collar diameter and biomass reached 23.73 cm, 3.03 mm and 0.68 g per plant, respectively, increasing by 19.42%, 7.44%and 15.25%, respectively, compared with that of the seedlings under overhead irrigation treatment .