不同水氮条件对岷江柏幼苗生长的影响

采用盆栽方法,设置2个氮水平和4个水分梯度,研究了不同处理条件对岷江柏幼苗生长的影响。结果表明,在15%,25%水分梯度上,氮肥抑制苗高生长,低氮的作用更为显著;在5%水分梯度上,低氮使苗高略减小,高氮则使苗高略增大;在30%水分梯度上,苗高增量随施氮量的增加而增加。在所有水分梯度上,氮肥显著地增加了苗木地径,且高氮更为显著。氮肥减小苗木高径比,在5%,15%水分梯度上,高氮的减少量更大;在25%,30%水分梯度上,低氮减少量更大。高氮减小各水分梯度上的根冠比,低氮在5%,30%水分梯度上减小根冠比,在15%,25%水分梯度上则增大根冠比。在5%水分梯度上,氮肥使苗木质量指数略有增大,且低氮较高氮作用明显;在15%水分梯度上,低氮略增大苗木质量指数,高氮略减小苗木质量指数;在25%,30%水分梯度上,苗木质量指数随施氮量的增大而减小。

Effects of Different Moisture Gradients and N-fertilizer Levels on Cupressus Chengiana Seedling Growth

The effects of different treatments on Cupressus chengiana seedling growth were studied by a pot experiment with 2 N-fertilizer levels and 4 moisture gradients.Results showed that at the 15% and 25% moisture gradients,N-fertilizer restrained the height of seedlings and low N-fertilizer level had more significant influence;at the 5% moisture gradient,low N-fertilizer level slightly reduced the height and however,high N-fertilize level slightly increased the height;and at the 30% moisture gradient,the height increased with the increased quantity of N-fertilizer.At all the moisture gradients,N-fertilizer significantly increased the basal diameter of seedlings and high N-fertilizer level had more significant influence.N-fertilizer reduced the the height-diameter ratio of seedlings;at the 5% and 15% moisture gradients,high N-fertilizer level had more significant influence;and at the 25% and 30% moisture gradients,low N-fertilizer level had more significant influence.High N-fertilizer level reduced the root-shoot ratio of seedlings at all the moisture gradients;low N-fertilizer level reduced the ratio at the 5% and 30% moisture gradients,while increased the ratio at the 15% and 25% moisture gradients.At the 5% moisture gradient,N-fertilizer slightly increased the quality index of seedlings and the low N-fertilizer level had more significant influence;at the 15% moisture gradient,low N-fertilizer level slightly increased the index and high N-fertilizer level slightly reduced the index;and at the 25%,30% moisture gradients,the index increased with increased quantity of N-fertilizer.