The invention provides compositions comprising a polymeric carrier of cellulose and/or starch, and an element. The carrier is insoluble in water and a salt of the element is soluble or partially soluble in water. The compositions include at least about 5% (wt/wt) of the element, based on a total weight of the composition, and have particle sizes between about 0.05 mm and about 1.5 mm. Also provided are methods of making such compositions and methods for using the compositions to deliver the element to a plant.