Effect of Diverse Compost Products on Potato Productivity and Soil Quality

Abstract

Quality and productivity of potato fields in New Brunswick, Canada has been declining due to intensive production practices. Compost addition may rapidly increase soil organic matter and reverse declining productivity. Five diverse compost products were fall-applied at 45 Mg/ha dry weight in 2015 and 2016 to field plots, also receiving inorganic fertilizers, and were compared with a no-compost control for effects on tuber yield and selected soil quality (SQ) indicators. Compost affected soil nutrient availability (particularly K) and pH; permeability; carbon content; and biological activity. Responses in SQ indicators varied with the properties of compost applied. Reductions in soil-borne diseases were observed in the field and in a complementary growth room experiment, but effects were inconsistent. Despite SQ improvements, no significant potato yield response was observed. Overall, results suggest that mature compost products, high in carbon and dry matter, are most suitable for enhancing SQ in potato production systems.