Mineral elements in clover- and grass forage in Sweden

Abstract: Minerals are essential elements for all living organisms. Plants and animals need minerals to function and maintain a balanced physiological state. Minerals are also important in the ecological cycle. The minerals originate in the soil and makes the foundation of the plants nutritional value for the animals. The minerals can later re-circulate to the soil in form of manure. Forage is the main feed giving to ruminants and knowledge about the mineral content in the forage is important to avoid deficiencies or toxicities and to get a good under-standing about the mineral balance of the farm. This study aimed to map the contents of calcium, phosphorus, magnesium, potas-sium, sodium, chlorine, sulphur, iron, manganese, zinc, copper, cobalt, selenium, iodine and molybdenum in clover- and grass forage in Sweden and to correlate those with the content of minerals in the soil of Sweden. The results generated 15 different maps showing the content of each mineral in samples of forages from all over Sweden. The results from the regression analysis between minerals in soil and feed, showed a varied relation, where calcium, phospho-rus, copper and molybdenum had the strongest determinations coefficient of 50% - 65%. It was concluded that this study showed mean concentration of calcium, phosphorus, magnesium, potassium, sulphur and copper comparable, to previously reported for Swedish forage. The mean contents of zinc, manganese and selenium, were however higher than those reported earlier and should therefore be the new refrence values for Swedish forage. This study also showed a difference in the phosphorus concentration between the northern and southern Sweden, which contradicts previously reported values of phosphorus in Swedish forage.