施用沼液对柑桔产量和品质以及土壤环境的影响

利用沼气发酵处理规模畜禽养殖场废水是综合治理畜牧业污染的主要途径之一,但大量沼液出路问题亟待解决。通过柑桔栽培过程中不同沼液灌溉量的多重复随机区组田间小区试验,对沼液不同灌溉量处理与常规施用化肥的对照处理进行了对比,结果表明,施用沼液可促进柑桔生长,对衡量土壤质量的几种重金属含量等基本无不利影响,且土壤中总氮、有机质等有所增加。用300000kg·hm-2沼液浇灌替代化肥,可使柑桔增加产量8.59%,还可增加柑桔果实可溶性固形物含量,沼液处理A的果实中总糖比化肥对照提高0.6个百分点,总酸降低0.262百分点,果实糖酸比明显提高,糖酸比与施用化肥的对照相比差异达显著水平（P〈0.05）,改善了柑桔的部分品质指标。合理施用沼液进行柑桔灌溉不仅可以减少作物化肥施用量,还能缓解规模养殖场污水处理的排放压力。

Influence of Applying Biogas Slurry on Yield and Quality of Citrus and Soil Environment

Biogas fermentation of wastewater released from livestock and poultry farms is one of the most important ways to comprehensively manage the stock raising pollution. However, disposal of a large amount of biogas slurry has become a challenge. In this study, incorporating biogas slurry in irrigation on citrus was investigated. Field plot experiments with multi-repeat randomized blocks design were performed to assess the influence of different amount of biogas slurry on soil property and the yield and quality of citrus. The results showed that biogas slurry irrigation could promote citrus growth and improve the soil quality by increasing the total nitrogen and organic matter but had no detrimental effect on the heavy metal contents of the soil compared with the blank controls using general chemical fertilizer. Production of citrus was increased by 8.59% with application of 300 000 kg·hm-2 biogas slurry instead of chemical fertilizers. The soluble solids content of fruit was improved as well. Total sugar of fruit was increased by 0.6% and total acid was decreased by 0.262%. The ratio of sugar to acid was significantly higher than that of the blank control（P0.05）. Hence, incorporating biogas slurry in citrus irrigation could not only decrease the use of chemical fertilizer but also provide a way to deal with biogas slurry.