| 【Objective】The potential quality security of agricultural products caused by high metal residues
produced by intensive pig breeding is widely concerned. This study aims to reveal the influence of metals in pig manure
on fruit quality and metal concentrations in litchi, and provide references for the reasonable and safe application of animal
manure in litchi. 【Method】 Successive field experiment was carried out to investigate the role of pig manure bearing Fe,
Mn, Cu and Zn on leaf photosynthesis and fruit quality of litchi during 2015-2018. Pig manures were applied at the rates
of 0, 20, 40 and 80 kg per plant each year. The security of manure application in litchi was discussed from the perspective
of litchi fruit quality. 【Result】Continuous application of pig manure did not impact leaf photosynthesis and fruit quality
including pulp pH, contents of soluble sugar and titratable acid, sugar acid ratio , flavor amino acid and total free amino
acid. And, Fe, Mn, Cu and Zn contents in litchi pulp were not increased by increased manure rate and application time,
even their contents in the manure were high up to hundreds to thousands of mg per kg.【Conclusion】It suggests that
repeated application of pig manure containing high contents of metals for three consecutive years does not bring about
fruit quality and security risks in litchi. |
