How do foliar applied nutrients work and are they an effective way to apply nutrients to pastures?

Plants can absorb water and dissolved nutrients through their leaf and stem tissues, although not as efficiently as through root tissues. There have been many studies on a wide variety of plants looking at the efficiency and effectiveness of foliar applied nutrients. In general, foliar applications for crops and forages, including pastures, are most commonly used for application of micronutrients such as zinc or boron in situations where plant deficiencies have been identified. Foliar fertilizers containing nitrogen, phosphorus, or potassium are usually low analysis formulations to prevent tissue burn, so foliar applications would not be recommended as a primary fertilizer source for these macronutrients. When considering use of a foliar fertilizer product, determine whether the nutrients supplied are actually needed by your pasture through soil and/or plant tissue analysis and whether foliar fertilization is your most practical and economic option to supply plant nutrient needs. For additional information on soil or plant tissue analysis, please contact your local UW Extension office.