Fertilization of a mixed forage crop with fresh and composted chicken manure and NPK fertilizer: Effects on dry matter yield and soil and tissue N, Pand K

An experiment was conducted for 3 yr to compare the effects of fertilizatio n of mixed forage with fresh and composted chicken manure and inorganic NPK . Fertility amendments were applied each year at three N levels and an unfe rtilized treatment was included. The experiment was conducted in two hay fi elds near Truro, Nova Scotia. Dry matter yield and forage N, P and K conten ts are reported for the 1992 and 1993 seasons. The nutrient content of the amendments as well as the efficiency of P and K use are discussed. Soil Meh lich 3-extractable P and K and KCI-extractable N were measured at two depth s in September 1993. By the final year of the experiment, compost amendment s produced yields as high as the recommended rate of NPK fertilization at b oth sites on both harvest dates. Medium rates of compost application also r esulted in tissue N levels as high as or higher than the equivalent NPK tre atments. The medium rate of manure application was equivalent in yield and tissue N to the compost treatments at the Acadia site, but had slightly low er yields and tissue N content at the Pugwash site. Compost P and K were re latively inefficiently used by the forage; this resulted in increased level s of Mehlich 3-extractable P and K in the 0- to 15-cm layer of the compost- amended plots. It was concluded that fertilization with compost or inorgani c NPK, supplying equal amounts of N, can result in comparable yields and qu ality of forage.