园林废弃物覆盖材料组分及厚度对土壤化学性质的影响

Effects of Composition and Thickness of Green-waste Mulches on Soil Chemical Properties

为研究城市园林废弃物不同组分用于地表覆盖对土壤基本化学特性的影响,以期为城市园林废弃物的循环利用提供参考依据。选用园林植物养护修剪废弃物,设置4种材料组分类型(草屑、树叶、枝叶和树枝)、3种覆盖厚度(3、6、9 cm)的双因素完全随机试验,并以无覆盖物的裸土作为对照,通过21个月种植维护,对比分析覆盖物材料及厚度对土壤有机质、氮磷钾养分、pH及EC的影响。结果显示:与对照相比,各处理土壤有机质、全氮、全钾含量及氮磷钾养分有效性、EC均不同程度增加、土壤pH总体下降,其中以6 cm厚度草屑、枝叶及9 cm厚度树枝覆盖土壤pH下降最显著;覆盖材料和厚度差异对土壤有机质、氮磷钾储量及有效性、EC均影响明显,且对部分指标影响有显著交互作用,而对土壤pH无明显影响;土壤EC与有机质、全氮、碱解氮、有效磷之间呈显著正相关、与pH值之间呈显著负相关。研究结果表明,园林废弃物地表覆盖能改善土壤有机质、养分条件、调节pH,其效果受材料种类和覆盖厚度影响,草屑、树叶、枝叶等覆盖厚度以6 cm为宜,树枝可覆盖厚度6 cm或9 cm。

This study was conducted to evaluate the influence of components of green-waste mulches on soil basic chemical characteristics,and promote the recycling of urban green waste.The pruning materials were collected and classified according to turfgrass clippings(TCS),leaves(LVS),mixture of branches and leaves(MBL)and branches(BCS),and were crushed and air-dried.A two-factor completely random experiment of material(CTS,LVS,MBL,BCS)and cover thickness(3 cm,6 cm,9 cm)and a bare soil treatment(CK)were arranged and as a control.The contents of soil organic matter(SOM),total nitrogen(TN),total phosphorus(TP),total potassium(TK),alkali-hydrolyzed nitrogen(AN),available phosphorus(AP),available potassium(AK),pH and EC were analyzed after 21 months of planting.The results showed that soil SOM,TN,TP,TK,AN,AP,AK and EC increased to varying degrees in mulch treatments compared with in CK,and soil pH decreased,among which,the soil pH decreased most significantly in TCS(6 cm),MBL(6 cm)and BCS(9 cm).The results of two-factor anova showed that the difference of mulching materials and thickness had significant influence on soil organic matter,nitrogen,phosphorus and potassium storage and availability and soil EC,and had significant interaction on some soil indexes,but had no significant influence on soil pH.Soil EC was positively correlated with SOM,TN,AN and AP,and negatively correlated with soil pH.The research results showed that green-waste mulches can improve soil organic matter,nutrient status and Regulate soil pH,and its effect is limited by mulching material composition and thickness.The covering thickness of TCS,LVS,MBL be 6 cm,and,and BCS 6 cm or 9 cm.