S13 - Session O4 - Organic matter amendments on nutrient and water status within subtropical peach orchards

Authors: Brian Lawrence *, Juan Carlos Melgar

Peach trees grow well on fertile soils, but high intensity management with bare soil and excessive inputs of chemical fertilizers encourages negative environmental impacts such as erosion and carbon loss within the soil. Organic matter (OM) amendments can increase soil fertility and quality, but unexplored consequences to tree water and nutrient status prevent grower adoption. We have recently added regional waste stream products including composted municipal mulch (M) and poultry litter along with the mulch (PM) to the soil surface underneath 'Scarletprince' peach trees and concomitantly reduced synthetic fertilizers. Following two years, OM content within the original soil has not changed beneath where M or PM were applied. Both amendments buffered soil moisture, but this trend did not always match tree water status measurements. However, nutrient status of trees receiving OM amendments were sufficient or comparable to trees receiving only synthetic fertilizers. This study suggests perennial fruit growing systems within subtropical climates should consider OM amendments as a possible strategy towards more sustainable orchards.