National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resource, College of Resources and Environment, Shandong Agricultural University, Tai'an, Shandong, 271018, China.
National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resource, College of Resources and Environment, Shandong Agricultural University, Tai'an, Shandong, 271018, China.
Environ Res. 2021 Mar;194:110711. doi: 10.1016/j.envres.2021.110711. Epub 2021 Jan 12.
Humic acid can improve soil nutrients and promote plant growth. Weathered coal and lignite can be used as agricultural resources due to high humic acid content, but their impact on soil NH volatilization and CO emissions are yet to be determined. In this study, a field experiment was carried out to compare the effects of four types of humic acid isolated from coal (pulverized weathered coal (HC), pulverized lignite (HL), alkalized weathered coal (AC) and alkalized lignite (AL)) on NH volatilization, CO emissions, pH, the C/N ratio and enzyme activities in soil cultivated with maize. The effect of biotechnology humic acids (BHA) was also examined for comparison. HL, AC, AL and BHA all increased cumulative NH losses by 147.7, 278.5, 113.9, and 355.3%, respectively, compared with the control (chemical fertilizer only), and notably, BHA caused an increase of 90.71% compared with the humic acids isolated from coal. A significant increase in cumulative CO losses was observed only under AL treatment, by 14.44-24.90% compared with all other treatments. Soil urease activity was positively correlated with cumulative NH losses (P < 0.001), while the soil C/N ratio (P < 0.001) and soil sucrase activity (P < 0.05) were positively correlated with cumulative CO losses. Since humic acid from pulverized weathered coal caused no increase in NH volatilization or CO emissions, it is therefore thought to be the most suitable humic acid for field application.
腐植酸可以改善土壤养分，促进植物生长。风化煤和褐煤由于腐植酸含量高，可作为农业资源加以利用，但它们对土壤 NH 挥发和 CO 排放的影响尚未确定。本研究通过田间试验比较了四种从煤中分离得到的腐植酸（煤粉风化煤（HC）、煤粉褐煤（HL）、堿化风化煤（AC）和堿化褐煤（AL））对玉米种植土壤中 NH 挥发、CO 排放、pH 值、C/N 比和酶活性的影响，并比较了生物技术腐植酸（BHA）的影响。HL、AC、AL 和 BHA 与对照（仅施用化肥）相比，分别使累积 NH 损失增加了 147.7%、278.5%、113.9%和 355.3%，而 BHA 与煤中分离得到的腐植酸相比，增加了 90.71%。仅在 AL 处理下观察到累积 CO 损失显著增加，与其他所有处理相比，增加了 14.44-24.90%。土壤脲酶活性与累积 NH 损失呈正相关（P<0.001），而土壤 C/N 比（P<0.001）和土壤蔗糖酶活性（P<0.05）与累积 CO 损失呈正相关。由于煤粉风化煤产生的腐植酸不会增加 NH 挥发或 CO 排放，因此被认为是最适合田间应用的腐植酸。
