Effect of Municipal Mulch and Poultry Litter Amendments on Soil and Tree Parameters of a Mature Peach Orchard in a Humid Subtropical Climate

Abstract

AbstractApplying organic matter (OM) amendments in mature peach orchards with low organic matter content (Prunus persica (L.) Batsch.) may improve tree nutrient and water status during the growing season and enable growers to reduce synthetic fertilizer inputs. Three treatments were applied to “Juneprince” and “Scarletprince” peach trees: (1) grower standard of bare soil (GS), (2) municipal mulch (M), and (3) poultry litter with municipal mulch (PLM). Synthetic fertilizer was reduced within the M and PLM treatments each year. Soil samples were taken from under the amendments, and the nutrient and water status of the soil and trees were monitored over 3 years. Fruit yield and tree growth measurements were also recorded. Soil OM did not increase, but soil P increased in all three treatments over time. Soil Cu was reduced by adding OM amendments, while PLM increased soil Na and increased leaf K in “Scarletprince” trees. The PLM and M treatments buffered soil water compared to GS, but tree water status between treatments was largely similar. The elevated N status over time from the PLM and M treatments delayed fruit maturity and reduced cumulative yield in “Juneprince” trees. The PLM treatment increased “Scarletprince” fruit size and mass over 3 years, as well as tree size compared to GS. Covering the soil with mulch allowed for reduced synthetic fertilizer use, but further reduction of supplemental synthetic fertilizer or adjustment of amendment rates is needed to limit N and ensure desired fruit harvest windows and long-term production.