贺丽群 张庆金 吴培栋 余晓玲 冯曾威 姚青

摘要：【目的】比较施用有机肥和/或生物炭及二者互作对城市底土肥力及生菜生长的影响，为利用有机肥和生物炭对城市底土进行改良提供理论依据。【方法】以典型的城市底土为试验对象、生菜为供试作物，设有机肥和生物炭均不施用（-C-B，对照）、施有机肥不施生物炭（+C-B）、不施有机肥施生物炭（-C+B）、同时施用有机肥和生物炭（+C+B） 4个处理，测定生菜植株叶片的叶绿素相对含量（SPAD值）和地上部生物量、土壤的化学性状和酶活性，研究有机肥和生物炭及其互作对生菜生长和底土肥力的影响。【结果】与对照（-C-B）相比，同时施用有机肥和生物炭（+C+B）的处理效果最好，生菜植株生物量增长4.27倍，显著提高底土中有机质、有效磷、有效钾和NO3-的含量（P<0.05，下同），显著增强底土中碳循环、磷循环和氮循环相关的酶活性。此外，有机肥和生物炭在增强纤维素二糖水解酶、磷酸单脂酶、丙氨酸氨肽酶和亮氨酸氨肽酶的活性上存在正向互作效应。方差分解分析结果揭示有机肥的促进作用（93.3%）远大于生物炭（4.6%），多元线性回归分析结果表明土壤中有效磷和NO3-含量的提高是生物量增加的决定性因子。【结论】同时施用有机肥和生物炭能有效提高城市底土的肥力，两者存在正向协同效应，有机肥是生物炭发挥作用的前提。

关键词： 城市底土;生菜;有机肥;生物炭;土壤改良;土壤肥力

中图分类号： S158;S636               文献标志码： A 文章编号：2095-1191（2019）08-1701-08

Effects of compost and biochar interaction on urban subsoil fertility and plant growth of lettuce

HE Li-qun， ZHANG Qing-jin， WU Pei-dong， YU Xiao-ling，

FENG Zeng-wei， YAO Qing*

（College of Horticulture， South China Agricultural University， Guangzhou  510642， China）

Abstract：【Objective】The effects of compost and/or biochar application and the interaction between the two on the fertility of urban subsoil and the plant growth of lettuce（Lactuca sativa L.） were compared，in order to provide the theoreti-cal basis for the improvement of urban subsoil with compost and biochar. 【Method】With typical urban subsoil as target and lettuce as tested crop，four treatments were set up， including no application of compost or biochar（?C‒B， control）， application of compost but no biochar（+C‒B）， application of biochar but no compost（‒C+B）， application of both compost and biochar（+C+B）. The relative chlorophyll content（SPAD value） in leaves of lettuce plants，shoot biomass， soil chemical properties and soil enzyme activities were measured to study the effects of compost and biochar as well as their interaction on the subsoil fertility and lettuce growth. 【Result】Compared to the control（‒C‒B），the treatment of application of both compost and biochar（+C+B） showed the best effects，with lettuce plant biomass increasing by 4.27 times. App-lication of both compost and biochar（+C+B） significantly increased the contents of organic matter，available phosphorus，available potassium and NO3- in subsoil（P<0.05，the same below），and significantly enhanced the enzyme activities involved in carbon cycling，phosphorus cycling and nitrogen cycling. In addition， compost and biochar positively interacted in the enhancement of cellobiosidase，phosphomonoesterase，alanine aminopeptidase and leucine aminopeptidase activities. Variance partitioning analysis revealed the far greater effect of compost（93.3%） than that of biochar（4.6%）. Multiple linear regression analysis indicated that the increase in available phosphorus and NO3- contents was the determinant of plant biomass enhancement. 【Conclusion】The application of both compost and biochar can effectively increase the urban subsoil fertility with positive synergistic effect，and application of compost is the precondition for biochar effect.

Key words： urban subsoil; lettuce; compost; biochar; soil improvement; soil fertility

0 引言

【研究意义】底土是分布在表土下面的……