林业废弃物基质配方特性及其对柚木生长的影响

为促进林业废弃物资源化利用，减少草炭的开采，以林业废弃物为育苗基质主要原料，对柚木Tectona grandis进行育苗试验，探讨林业废弃物替代草炭作为柚木育苗基质的可行性。试验以木纤维、锯末、椰糠和沤制树皮为主要基质原料，分别与辅料草炭、黄心土、珍珠岩、蛭石（VC）和火烧土（BS）以不同的体积比混合配制成16种不同配方基质，并以柚木常用基质黄心土为主要基质原料的配方T₁V（黄心土）:V（锯末）:V（火烧土）=6:3:1]作为对照，分别研究了不同基质的特性及其对柚木幼苗生长和生理状况的影响，采用隶属函数值法对各基质的育苗效果进行综合评价，筛选出适宜柚木幼苗生长的最佳基质配方。结果表明:16种林业废弃物基质的各项指标间均有差异，其中部分指标间差异显著（P＜0.05）。16种林业废弃物配方基质的容重、总孔隙度和毛管孔隙度分别为0.1~0.8 g·cm-3，35.87%~63.35%和24.78%~53.05%，pH值为5.29~7.43。其中以林业废弃物为主料配方基质的碱解氮、有效磷、速效钾质量分数和电导率通气孔隙度均高于或显著（P＜0.05）高于对照（T₁），容重显著（P＜0.05）低于T₁。在不同基质中，柚木幼苗的各指标均存在一定差异，其中T₁₀V（木纤维）:V（草炭）:V（珍珠岩）:V（蛭石）=5:3:1:1]，T₁₁V（椰糠）:V（木纤维）:V（草炭）=3:4:3]，T₁₂V（椰糠）:V（木纤维）:V（草炭）=3:3:4]配方基质中柚木幼苗的苗高增长量、地径增长量、主根长、单株侧根数、单株叶面积、单株茎叶干质量、单株根干质量、苗木品质指数、总叶绿素质量分数均较高，显著（P＜0.05）高于对照组的对应指标，表现出明显的生长优势。综合评价结果显示:柚木在T₁₀，T₁₁，T₁₂配方基质中的生长品质综合评价指数分别为0.42，0.42，0.56，均显著（P＜0.05）高于对照组的0.22。为减少草炭使用量，建议将T₁₁和T₁₀作为柚木最佳育苗基质配方。

Matrix formula with forest waste and their effects on Tectona grandis growth

To promote the utilization of forest wastes and reduce the exploitation of peat, a seedling test on Tectona grandis was conducted with the main raw materials of forest wastes as the seedling substrate. Taking wood fiber (WB), sawdust (SD), coir dust (CD), and retted bark (RB) as main raw materials and peat (PT), yellow soil (YS), perlite (PL), vermiculite (VC), and burned soil (BS) as auxiliary materials, 16 different matrix formulations were mixed with different volume ratios. The control (T₁) formula was YS:SD:BS=6:3:1. Physicochemical properties of the substrates and their effects on the growth and physiological status of T. grandis seedlings were studied using the subjection function method to evaluate the effect of each substrate on seedling growth. Then, the best suitable matrix formulation for seedling growth was screened out. Results showed significant differences (P < 0.05) between indicators of different substrates. Of the sixteen kinds of forestry waste formulation substrates, bulk density was 0.1-0.8 g·cm-3, total porosity was 35.87%-63.35%, and capillary porosity was 24.78%-53.05%; pH was 5.29-7.43. Compared to the control, available N, available P, available K, EC, and aeration porosity were higher or significantly higher (P < 0.05); bulk density was significantly lower (P < 0.05). Differences among the indexes included T₁₀, T₁₁ and T₁₂. For height growth and increment of soil diameter in the formulation matrix, main root length, the number of lateral roots per plant, the leaf area per plant, leaf stem and leaf dry weight, root dry weight, seedling quality index, and total chlorophyll were significantly higher (P < 0.05) than the control group. The comprehensive evaluation results showed that the comprehensive evaluation indexes of T₁₀, T₁₁ and T₁₂ are 0.42, 0.42, and 0.56 were significantly (P < 0.05) higher than those of the control group (0.22). Thus, to reduce the use of peat, T₁₀ and T₁₁ were recommended as the best seedling substrates for T. grandis.