2022 Volume 68 Issue 2 Pages 73-84
We have suggested that fertilizer recommendations can be measured by a linear regression formula showing the relationship of the herbage consumption and the demand of fertilizer application in previous study in the central Hokkaido. In this study, we applied that regression lines to 47 pastures among two study sites in the eastern Hokkaido to verify their utility. Although herbage intake per body weight depends on individual weight, herbage consumption was able to be estimated by multiplying the total body weight of cattle throughout the grazing period by 2.38% derived from the previous study mentioned above. Fertilizer recommendation for each pasture was predicted by substituting the herbage consumption into the regression formula. The nutrient balance of grazed sward was calculated as the annual fertilizer application rate minus the fertilizer recommendation. The nutrient balance was compared with the change in soil nutrients before and after grazing period. The results of the comparisons were consistent with those obtained from the previous study with the same level of accuracy. Although relatively large differences were shown in pastures that sloped steeply or were affected by ground water. These findings will enable the formulation of fertilization strategy concurrent with drafting a grazing plan.
