Tillage and phosphorus effects on silage corn

Abstract

No tillage (NT) has an advantage over conventional tillage (CT) in hilly lands of the Appalachian region of the Eastern U.S. because it reduces soil erosion and lowers energy input. Field experiments were conducted for three years (at an elevation of 908 m) to evaluate the effects of tillage (CT, NT) and P rates (25, 200 kg P ha-1) on shoot and root growth and nutrient uptake by silage corn (Zea mays L.). Shoot dry matter yields, root length per plant, and root density in NT were significantly higher than in CT. In both tillage treatments, higher levels of P improved shoot and root growth. In all treatments, the majority of the roots were close to the plant row. With the exception of uptake of K, Mg, and Mn, the uptake of all nutrient elements — including N, P, Ca, S, Zn, Cu, and Fe— was significantly higher in NT than in CT. High levels of P significantly enhanced the uptake of all nutrient elements except Zn, Cu, and Fe. Enhanced dry matter yield and nutrient uptake under NT could be related to greater root length and root density. The results show that NT has an added advantage in enhancing the production potential of the steep, hilly lands of Appalachia.