湿地松中龄林施肥经济效应与最优施肥量研究

Study on the economic effect of fertilization and the optimal amount of fertilization in the middle age Pinus elliottii plantation

【目的】使用常用农用肥料,探讨不同肥料及不同施肥量处理下湿地松的生长效益差异,并且估算不同成本施肥处理的经济效益,分析讨论合理的湿地松中林龄施肥方案,以期为湿地松高效培育提供技术支撑。【方法】分别在2个立地条件不同的湿地松林分中设置施肥试验样地,每个样地总共设计8种施肥处理,每个处理小区5株,重复3次。【结果】施肥对促进湿地松树高、胸径生长效果显著,其中P肥对促进湿地松树高生长效果显著,N肥对促进湿地松胸径生长效果显著,而K肥对湿地松生长促进作用相对较小。当硫酸钾复合肥用量达到300~400 g时对湿地松胸径和树高均有显著的促进效果,但再进一步提高复合肥用量时湿地松生长量没有显著提升。与不施肥的对照组相比,四纪红壤的湿地松林分施肥后胸径、树高净增长量更高。而在板页岩红壤湿地松林分施用复合肥,达到相同的增长效果需要消耗更多的肥料。但板页岩红壤湿地松林分施肥效益率更高,说明在板页岩红壤林分中,湿地松施肥后相对不施肥对照组的增益百分比要相对更高。【结论】施肥能够为湿地松培育带来显著的经济效益。考虑施肥成本和效益率,在四纪红壤湿地松林分经济效益最好的施肥处理方案为处理5,即每株湿地松施用300 g硫酸钾复合肥,每年能够提升大约13%的经济收益;而在板页岩红壤湿地松林分经济效益最好的施肥处理方案为处理6,即每株湿地松施用400 g硫酸钾复合肥,每年能够提升大约16%的经济收益。

【Objective】The growth benefit of slash pine and the economic benefit of different cost fertilization treatment were discussed by using common agricultural fertilizer.Analysis and discussion a reasonable fertilization scheme for middle age of Pinus elliottii,in order to provide scientific and technical support for the cultivation of fast-growing and high-quality Pinus elliottii.【Method】Fertilization test plots were set up respectively in two 8-year-old Pinus elliottii stands with different site conditions,and 8 kinds of fertilization treatments were designed for each sample plot,5 plants in each sample plot,repeated 3 times.【Result】Fertilization has significant effect on the growth of height and DBH of Pinus elliottii.P fertilizer has a good effect on the height growth of Pinus elliottii,N fertilizer has a good effect on the DBH growth of Pinus elliotti,while K fertilizer has a relatively small effect on the growth of Pinus elliottii.When the dosage of potassium sulphate compound fertilizer reaches 300-400 g,it can promote the DBH and tree height of Pinus elliottii significantly,and the growth of Pinus elliottii was not significantly increased when the amount of compound fertilizer was further increased.The effect of fertilization was more significant in the test forest of Pinus elliottii with better site conditions.More fertilizer is needed to achieve the same effect when compound fertilizer is applied to the general experimental forest of shale laterite.【Conclusion】Fertilization can bring significant economic benefits to the cultivation of Pinus elliottii.Considering the cost and benefit rate of fertilization,the best scheme of fertilization treatment is treatment 5 inthe plot with quaternary laterite,it can increase the economic income by about 13%every year.While the best scheme of fertilization treatment is treatment 6 in the plot with shale laterite,it can increase the economic income by about 16%every year.