稻田施用菌渣土壤团聚体的组成及评价

Effect of Application of Mushroom Residue on Composition of Soil Aggregates in Paddy Field and Its Evaluation

通过采集6 个不同菌渣用量处理的土壤,在实验室进行土壤筛分,研究稻田施用不同用量菌渣下土壤团聚体的组成,并对土壤团聚体的稳定性进行评价.结果表明,施用菌渣在-定程度上改变了土壤团聚体的分布.总体来看,不同处理土壤团聚体的优势粒级为〉2.0、〉0.5～1.0 和〉0.25～0.5 mm,施用菌渣提高了土壤中〉2.0 mm团聚体含量,且菌渣施用量越高,〉2. 0 mm 团聚体含量越高.平均重量直径（MWD）和几何平均直径（GMD）随菌渣用量的提高而增加（中量菌渣处理除外）.分形维数随菌渣用量的提高而减小.相关分析表明,MWD 和GMD之间呈显著正相关,〉2.0 和〉1. 0～2.0 mm 土壤团聚体含量分别与MWD 和GMD 呈显著正相关,与分形维数呈负相关,但不显著,指标MWD 和GMD 适用于该菌渣处理的〉2.0 和〉1. 0～2.0 mm 土壤团聚体稳定性评价.

Soil samples were collected from paddy fields different in mushroom residue application rate for analysis in la.boratory of composition and stability of soil aggregates. Results show that application of mushroom residue changed the dis.tribution of soil aggregates to a certain extent. All in all, soil aggregates 〉2. 0, 〉0.5-1. 0 and 〉0. 25-0.5 mm were domi.nant fractions, regardless of treatment （mushroom residue application rate）. Application of mushroom residue increasedthe content of 〉2. 0 mm soil aggregates, and the higher the mushroom residue application rate, the higher the content of〉2.0 mm soil aggregates. Mean weight diameter （MWD） and geometric mean diameter（GMD） increased with risingmushroom residue application rate （except for MR3）, while fractal dimension decreased with the rising rate. Correlation a.nalysis shows that MWD is significant and positively related to GMD, and the contents of 〉2.0 and 〉1.0-2.0 mm soil ag.gregates are significantly and positively related to MWD and GMD, but negatively related to fractal dimension, though notsignificantly. MWD and GMD could be used as indices in evaluating stability of 〉2.0 and 〉1.0-2.0 mm soil aggregates insoils applied with mushroom residue.