| Popis: |
Field studies were conducted on Ladino clover, orchardgrass, smooth bromegrass, and timothy. Each species was planted in a pure stand to determine its requirements with respect to P and K. Increases of 30% to 80% in hay production were obtained when adequate K was applied. Split applications of K fertilizer were used instead of single large applications. Although the percentage P in the plant material increased with added increments of P, there was no appreciable yield response to P on most species above the lowest P rate. Phosphate needs of the crop for 3 to 4 years can be met by banding 50 to 100 pounds P₂O₅ per acre at seeding time. Although liberal amounts of fertilizer potash were applied to the grasses studied there was nearly complete removal of applied K (79 to 94%). This points up the fact that it is not possible to increase the reserves of soil K when producing large yields of the forage grasses, smooth brome, orchard, or timothy on this and similar soils. Competition for K between desirable forage species and undesirable weedy species has a pronounced influence on the longevity of the stand. By the spring of the third crop year, Ladino clover comprised less than 5% of the vegetation on low K plots. The remaining vegetation was predominantly the weedy grasses, Kentucky bluegrass, and bentgrass. |
