Effect of Diverse Compost Products on Potato Yield and Nutrient Availability

Compost application to agricultural fields can increase soil organic matter content and soil productivity. This study compared diverse compost products with a non-amended control in small plot and on-farm trials for effects on tuber yield and plant nutrient availability under rain-fed potato production in New Brunswick, Canada. In the small plot trial, mature compost products resulted in a small increase in plant N availability, whereas immature products resulted in net N immobilization. Composts high in K increased plant K availability. However, these effects on nutrient availability did not result in a significant effect on tuber yield. In on-farm trials, compost did not significantly increase yield averaged across 19 site-years of trials. This suggests that any short-term nutrient benefit from application of these wood waste and manure based composts is unlikely to influence crop yield, although there may be the potential to reduce nutrient application rates, particularly for K.