Enrichment of soil
Indirect provision of minerals to grazing livestock includes mineral fertilization of pasture and altering soil pH, however this may not be always feasible due to complex soil – plant - animal interrelationship. In the indirect approach, soil treatment of deficient minerals would make these elements accumulate in plants. For instance soil treatment of cobalt and selenium will improve their concentration in plants without having any effect on plant yield. This effect may be neutralized in high alkaline or calcareous soils, as the uptake of cobalt by plants in such soils would be affected. Copper application makes it more available to plants in soils low in molybdenum content, but will not be effective when soils contain high molybdenum. High application of NPK fertilizers reduces the calcium, magnesium and sodium availability to plants. So the approach to enrich the soil through micronutrient supplementation may not be very cost effective and also may not yield the desired results due to the variation in soil profile in different zones. Trace element intakes that can be improved by fertilization include selenium, cobalt, copper, zinc, boron, and possibly nickel.