Determining Optimum Rate and Timing for Applying Poultry Manures on a Perennial Grass.

Application of poultry litter to grass for production of silage and hay as dairy feed can improve the regional nutrient balancing in the Lower Fraser Valley of British Columbia. Even though poultry litter is often applied to grass there are no clear agronomic recommendations, often leading to over-application and possible loss of nutrients to the environment. This study aims to determine optimum rate and timing for applying poultry manures on a perennial grass (tall fescue). For 2016 grass crop, nitrogen response patterns for poultry litter and fertilizer were similar based on total applied N. Splitting application into three equal mounts over the growing season or application later in the season reduced yield relative to a single spring application. With a single spring application yield was slightly lower with broiler litter than with chemical fertilizer, whereas a single application of poultry litter in the fall or mid-winter performed similarly to a single fertilizer application in spring. At equivalent N rates (200 kg /ha) applied once, crop yields were similar for spring applied fertilizer (10.4 t DM/ha), fall and winter applied broiler litter (10.7 and 10.4) and spring applied layer manure (10.5) but significantly higher than spring applied broiler and turkey manures (9.4 and 8.4). For Nitrogen Use Efficiency (N uptake/ applied N) fertilizer (64%) > layer manure (55%) > spring and winter applied broiler litter (44 and 39%, respectively) > fall applied broiler litter and spring applied turkey manure.