农林废弃物混配基质的理化性质及其对油茶幼苗生长效应的综合评价

以腐熟的甘蔗渣( SB)、木薯皮( CP)、花生壳( PS)和火炭灰( BA)及园土( GS)为原料,按照不同体积比配制成9种混配基质,并以等体积比泥炭和园土混配基质为对照,对各基质的理化性质及基质中油茶( Camellia oleifera Abel)幼苗的生长状况进行比较；在对基质理化指标和油茶幼苗的壮苗指数进行线性回归分析和通径分析的基础上,采用主成分分析和综合评价法对各基质的育苗效果进行综合评价。结果表明：9种农林废弃物混配基质的容重、总孔隙度和毛管孔隙度分别为0.23~0.47 g·cm-3、60.90%~67.23%和46.53%~58.27%, pH 6.72~pH 7.14,各基质的速效氮含量、速效磷含量、速效钾含量、pH值、电导率和通气孔隙度均高于或显著高于对照,容重则显著低于对照。在不同基质中油茶幼苗的茎粗、单株叶片数、叶长、叶宽、叶绿素相对含量( SPAD)、单株茎叶干质量、单株根干质量和壮苗指数均存在一定差异,而株高和根冠比却无显著差异；其中S9混配基质也V( SB)：V( CP)：V( BA)=2：1：1页中幼苗的大部分生长指标较高,表现出明显的生长优势。线性回归和通径分析结果显示：除通气孔隙度外,基质的其他8个理化指标基本涵盖了影响幼苗壮苗指数的关键因素；其中,速效钾含量是对壮苗指数直接影响最大的负相关因子,而速效磷含量、电导率和总孔隙度对壮苗指数则有较大的正向直接作用,并且三者通过速效钾含量对壮苗指数产生较大的负向间接作用；此外,基质容重对壮苗指数也有一定的负向直接作用。综合评价结果显示：S9和S7混配基质也V( SB)：V( BA)：V( GS)=4：3：3页对油茶育苗效果的综合得分较高,分别为14.363和14.337,建议将S9混配基质作为油茶育苗的首选替代基质,S7混配基质作为备选基质。

Physicochemical property of mixed substrates with agricultural and forestry wastes and ;comprehensive evaluation of their effect on growth of Camellia oleifera seedlings

Taking decomposed sugarcane bagasse ( SB ) , cassava peel ( CP ) , peanut shell ( PS ) , bagasse ash ( BA) and garden soil ( GS) as raw materials, nine mixed substrates were prepared with different volume ratios. And taking mixed substrate with same volume ratio of peat and garden soil as the control, the physicochemical property of different substrates and growth status of Camellia oleifera Abel seedlings growing in above substrates were compared. On the basis of linear regression analysis and path analysis on physicochemical indexes of substrates and seedling index of C. oleifera seedlings, the seedling cultivation effect of different substrates was comprehensively evaluated by methods of principal component analysis and comprehensive evaluation. The results show that bulk density, total porosity and capillary porosity of nine mixed substrates with agricultural and forestry wastes are 0 . 23-0 . 47 g · cm-3 , 60. 90%-67. 23% and 46. 53%-58. 27%, respectively, with pH 6. 72-pH 7. 14. Available nitrogen content, available phosphorus content, available potassium content, pH value, electronic conductivity and aeration porosity of different substrates are all higher or significantly higher than those of the control, their bulk density is significantly lower than that of the control. There are all some differences in stem diameter, leaf number per plant, leaf length, leaf width, relative content of chlorophyll (SPAD), dry weight of shoot per plant, dry weight of root per plant and seedling index of C. oleifera seedlings in different substrates, while there is no significant difference in height and root-shoot ratio. In which, most growth indexes of seedlings in S9 mixed substrate 〔V( SB):V( CP):V( BA)=2:1:1〕 are high, appearing obviously growth advantage. The results of linear regression and path analysis reveal that except aeration porosity, other eight physicochemical indexes of substrates are basically covered key factors affecting seedling index. In which, available potassium content is negative correlation factor with the greatest direct effect on seedling index, while available phosphorus content, electronic conductivity and total porosity have a positively direct effect on seedling index, and the three bring negatively indirect effect on seedling index through available potassium content. Otherwise, bulk density of substrate also has a certain negatively direct effect on seedling index. The comprehensive evaluation result shows that comprehensive score of effect of S9 mixed substrate and S7 mixed substrate 〔V ( SB ):V ( BA ):V ( GS )= 4:3:3〕 on seedling cultivation of C. oleifera is high with a value of 14. 363 and 14. 337, respectively. So, it is suggested that taking S9 mixed substrate as preferred substitute substrate for seedling cultivation of C. oleifera, and taking S7 mixed substrate as alternative substrate.