磷肥对闽楠苗木生长及叶片氮磷钾浓度的影响

为了确定闽楠苗木的适宜施磷量,测定了8个水平施磷(0、7.5、15、22.5、30、40、60、90 mg/株)处理下闽楠苗木的生长特性和叶片养分状况。结果表明:(1)随着磷素供应水平的升高,闽楠苗高和总生物量均呈先升高后稳定的趋势,而地径呈增长—稳定—降低的趋势,拐点磷素供应量为22.5 mg/株;(2)随着磷素供应量的增加,闽楠苗木叶片氮和磷含量呈升高趋势,而钾含量先升高后降低; 当供磷量大于22.5 mg/株时,生物量未发生显著变化,说明此时植株对氮磷钾为奢侈消耗;(3)闽楠苗木叶片氮磷钾的临界含量分别为16.04、1.36和21.93 g/kg,最适含量范围分别为16.04～27.45、1.36～3.01和21.93～36.40 g/kg。综合分析认为,对闽楠苗木的最适施磷量为22.5～30.0 mg/株。

Effects of phosphorus fertilization on growth and foliar nutrient(N,P,K) of Phoebe bournei seedlings

To determine the optimal phosphorus need of Phoebe bournei seedlings, a pot trial was conducted with fertilization at levels of 0,7.5,15,22.5,30,40,60,90 mg per seedling. And the growth characteristics and foliar nutrient status of Ph. bournei seedlings were measured. The results indicated that:(1)Height and total biomass of Ph. bournei seedlings displayed growth-stability, with the increase of phosphorus supply,the ground diameter firstly went up, then was stable, finally decreased.(2)The leaf N and P concentrations grew up, but K display accelerated then went down as the phosphorus addition increased. The total dry biomass did not significantly change when phosphorus was above 22.5 mg per plant. So it suggested that the N, P and K were luxury consumed.(3)The critical values of N, P and K in leaf of Phoebe bournei seedlings were 16.04, 1.36 and 21.93 g/kg, respectively,while their optimum concentration range were 16.04-27.45,1.36-3.01 and 21.93-36.40 g/kg,respectively. Therefore,the optimal phosphorus amount for Ph. bournei seedlings might be 22.5-30.0 mg per seedling.