复合肥和磷肥混施对云南松幼林生长的短期效应分析

为了解复合肥(包括缓释肥)和磷肥配施对12a生云南松(Pinus yunnanensis)人工林施肥后1a时的短期生长效应,采用L₉(3⁴)正交设计开展试验实施。施肥后1a时,处理组合林木的胸径、树高和单株材积增长率分别达4.29%~12.37%,7.96%~22.58%和20.13%~38.39%,对照则是3.80%,10.21%和15.76%,处理组合间此3项指标具有极显著的差异(P<0.01)。影响胸径增长率的主导因子是肥料种类,树高和材积的是磷肥施肥量。随着磷肥施肥量的增加,树高增长率随之提高,胸径则相反。肥料种类和磷肥施肥量的交互作用对胸径和树高增长率具有极显著(P<0.01)和显著(P<0.05)的差异影响。云南松幼林胸径和树高生长对养分种类及其数量的需求具有差异,施肥以促进胸径生长为主。适宜的复合肥种类和磷施肥量配施可极显著促进林木生长。每5cm胸径作为计算施肥单位可实现精准施肥。综合理论与实际的最优处理组合,考虑到复合肥种类和磷施肥量交互作用结果,以及影响林木材积的主要因子,0.75和0.50kg/5cm的9个月缓释肥和磷肥配施可于1a的短期内促进云南松人工林幼林生长,提高林分蓄积量。

Short Term Effects of Compound and Phosphate Fertilizer on the Growth of Juvenile Pinus Yunnanensis Plantation

In order to understand the short-term(one year after fertilization)growth effects of compound fertilizer(including slow-release fertilizer,SRF)and phosphate(P)fertilizer on a 12-year-old Pinus yunnanensis plantation,the L₉(3⁴)orthogonal design was employed to implement the trial.At one year after fertilization,the growth rates of diameters at breast height(DBHs),tree height(THs)and individual tree volumes(ITVs)of treatment combinations(TCs)were 4.29%~12.37%,7.96%~22.58%and 20.13%~38.39%,while numbers of control were 3.80%,10.21%and 15.76%,respectively,which was of significant difference between the TCs(P<0.01).The dominant factor affecting growth rate of the DBH was the type of fertilizer,while which of the TH and ITV was the amount of the P fertilizer.The growth rates of the THs went up with the increase of P fertilizer application,while DBH was opposite.The interaction of fertilizer types and P fertilizer amount had significant difference effects on the DBH and TH growth rates(P<0.01 or P<0.05).The demand of nutrient types and quantity for the DBH and TH growth of juvenile P.yunnanensis was different,and the fertilization of the forest primarily focuses on promoting the DBH growth.Suitable types of compound fertilizer and P fertilizer amount could significantly improve the growth of trees.Accurate fertilization could be achieved by taking every 5cm diameter of the DBH as the calculation unit of fertilization.The combination of the 0.75 and 0.50 kg/5 cm of 9-month SRF and diammonium phosphate could promote the growth of juvenile P.yunnanensis plantation and increase the stand volume in a short period of one year after fertilization based on comprehensive results of the optimal combination of theory and practice,the interaction results of compound fertilizer types and P fertilization amount,and the dominant factors affecting the timber volume of the stand.