沼液配施化肥对蜜柚产量、品质及土壤重金属的影响

以8年生蜜柚为供试材料，通过连续3年施用猪粪沼液的田间定位试验，研究等氮磷钾条件下不同比例沼液与化肥配施对蜜柚产量、品质及土壤重金属和盐分的影响。结果表明，随沼液施用年限增加，TFN25%和TFN50%处理蜜柚增产优势逐渐显现，与TF处理相比较，试验第3年TFN25%处理的蜜柚产量增加了6.91%，果实粒化率和裂果率降低，Vc、可溶性糖含量和糖酸比提高。随沼液替代比例和施用年限的增加，土壤中Cu、Zn含量有显著增加，但均低于国家污染土壤的重金属限量标准，土壤电导率随沼液替代比例的增加而增加。综上，沼液替代25%化肥用量的处理在蜜柚果园应用效果较好，可在生产上推广，但长期沼液灌溉的影响还需进一步的观测和评价。

Effects of biogas slurry combined with chemical fertilizers on yield, quality of pomelo and heavy metals in soil

A three-year field experiment was carried out to study the effects of different proportions of pig manure biogas slurry combined with chemical fertilizers on yield and quality of 8-year old honey pomelo and soil heavy metals and salinity. The results showed that with the increase of the application years of biogas slurry, the yield of pomelo under the treatment of TFN25% and TFN50% gradually appeared. Compared with TF treatment, the yield of honey pomelo under TFN25% treatment increased by 6.91% in the third year of experiment, the granulation rate and fruit cracking rate decreased, and the content of Vc, soluble sugar and sugar-acid ratio increased.With the increase of biogas slurry replacement proportion and application years, the contents of Cu and Zn in soil increased significantly, but they were lower than the national limit standard of heavy metals polluted soil. The soil electrical conductivity increased with the increase of biogas slurry replacement proportion. In conclusion, biogas slurry replacing 25% chemical fertilizer has better application effect in honey pomelo orchards, which can be popularized in production. However, the effect of long-term biogas slurry irrigation needs further observation and evaluation.