2024 Volume 70 Issue 1 Pages 10-21
The applicability of the fertilizer recommendation estimation method developed for cattle grazed swards to sheep and horse grazed swards in Hokkaido was examined. For each pasture, the weight of grazing livestock was totaled per area, and 2.38% of the weight was estimated to account for herbage consumption. Using herbage consumption as an independent variable, we calculated the nitrogen, phosphorus, and potassium requirement using an estimation formula derived from the cattle grazing experiment. The difference between the fertilizer requirement and annual fertilizer application rate was used to obtain nutrient balance. The nutrient balance was compared with the changes in soil nutrients before and after grazing to verify the validity of the fertilizer requirements. The results of our estimation were consistent with those obtained from the cattle pasture experiment with the same level of accuracy. Relatively large outliers were assumed to be caused by land conditions such as slope and drainage permeability, and management conditions such as grazing pressure. This study made it possible to plan annual fertilizer application according to the total weight of sheep and horses during the grazing season, which was assumed at the time of grazing planning, based on the same logic as for cattle.
