河北平山县退耕还林树种施肥效果的研究

为解决河北平山研究区土壤肥力低下和造林树种生长缓慢的问题，该文以肥料施用技术为研究重点，采用完全随机试验设计方案，以平山研究区主要造林树种（核桃、花椒、侧柏）为研究对象，调查主要造林树种的生长量指标（株高、地径）和土壤养分含量指标，寻求主要造林树种的施肥方案和最佳施肥量。结果表明，所有施肥方案都能显著促进造林树种的生长。施用纯化肥1年后核桃地径和株高生长量平均提高39.3%和106.9%；施用2年后地径和株高生长量平均提高13.7%和169.7%。回归分析表明，纯化肥施肥方案中以93 ｇ/ 株施肥量（m（N）∶m(P2 O5)∶m(K2 O)=14∶8∶12）效果最佳。在纯化肥基础上增加微生物肥料，第1年的地径和株高生长量较纯化肥小，施用2年后地径生长量较纯化肥大（平均增加88.5%），表明微生物肥料可以缓解树木对化肥的奢侈吸收，使肥效更为长久。结果还表明，施用纯化肥2年后，核桃的株内土壤有机质增加43.00%，土壤全氮增加13.67%，有效磷增加16.27%，有效钾增加41.13%，有效锌增加21.15%，有效锰增加69.14%。这一结果表明通过施肥可以提高土壤肥力水平，解决平山研究区土壤肥力低下造成苗木生长缓慢的难题。 

Effects of fertilization on the growth of trees in forestland conversed from farmland in Pingshan County,Hebei Province of northern China

Afforestation trees grow slowly because of low soil fertility in Pingshan County,northern China's Hebei Province.The purpose of this study is to identify the optimal scheme and quantity of fertilization to enhance the growth of several major afforestation tree species,including Juglans regia,Zanthoxylum bungeanum and Platycladus orientalis.A complete randomized design was used to investigate the growth indices such as plant height and ground diameter.Results indicated that all fertilization schemes were eff...