Developing a fertilizer and manure nitrogen database for crops in Canada
Yang, J.Y., Drury, C.F., Yang, X.M., Reid, K. 2017. Developing a fertilizer and manure nitrogen database for crops in Canada. Oral presentation In: 2017 Annual Meeting of Canadian Society of Soil Science, The Trent University, Peterborough, Ontario 2017/06/10 - 2017/06/14
Accurate estimating the fertilizer and manure nitrogen (N) application rates applied to field crops is a key component to the development of the reactive N model for agriculture. This paper presents updated methods to allocate manure N and fertilizer N to Canadian farmland by crops. Manure N was allocated to priority crops in the order of grain corn, hay, spring wheat, spring cereals, winter wheat, canola, pulses, improved pasture, vegetables and unimproved pasture, based upon 75% of the N recommendation rate for these priority crops. If extra manure is available for a particular region, then it will be allocated to all crops equally in the region. Fertilizer N application rates were then adjusted by subtracting manure N application rate from the recommendations for each crop. After this step, the fertilizer N application rates were further adjusted to ensure that fertilizer allocation was equivalent to fertilizer N sales at the provincial level. Legumes, pasture and nursery crops are assumed to not have any fertilizer N applied. A new CANB-reactive N model is being developed that will incorporate these allocation methods. When these changes were implemented for the 2011 census year, the fertilizer N application rates decreased by 32 kg N ha-1 for grain corn, decreased by 13 kg N ha-1 for spring wheat and decreased by 5 kg N ha-1 for spring cereals while notable increases of fertilizer N rates occurred for silage corn (17 kg N/ha) and potato (14 kg N/ha). Fertilizer and manure N dataset were then developed at the Soil and Landscapes of Canada polygon scale and this dataset could also be available for other modelling projects.