Additional information is contained in the Manitoba Agriculture and Food's fact sheet Fertilizing Alfalfa Forage . Inoculate legume seed before planting. Sulphur deficiency may occur in many soils and in any area of the province. A soil test is recommended to determine the available sulphur status of fields. The micronutrient boron is particularly important for alfalfa.
Visual deficiencies appear as yellowing to reddening of the youngest upper leaves on the plant.
Deficiencies are generally limited to high pH, sandy soils when plants are under drought stress. Since deficiencies are often weather-related, they may be observed one year and not the next. Confirm deficiencies with soil and plant-tissue analysis. Apply boron with caution, since excessive boron can cause toxicity in following crops such as oats and beans. Fertilizing mixtures of grasses and legumes If the mixed stand contains more than 25 per cent legume, fertilize as for a pure legume stand.