Effects of Long-Term Nitrogen, Phosphorus, and Potassium Fertilization on Chenin blanc Vines. I. Nutrient Demand and Vine Performance

Abstract

The effects of nitrogen (N), phosphorus (P), and potassium (K) fertilization were investigated in a field trial with Vitis vinifera L. var. Chenin blanc over a period of 11 years. Three levels of N (16, 56, and 96 kg N/ha/yr), P (0, 9, and 18 kg P/ha/yr), and K (0, 45, and 90 kg K/ha/yr) were tested in a 3 x 3 x 3 factorial layout on a gravelly sandy loam soil containing 1.1% organic material, 12.7 mg P/kg, and 38 mg K/kg. Nitrogen fertilization increased yield and shoot growth slightly but reduced the pH of the topsoil. It was concluded that the N-supplying capacity of the soil was nearly sufficient to satisfy the N demand of the vines, which had an average yield of 13t/ha, and that an additional fertilization of only 40 kg N/ha was justified in this case. Phosphorus fertilization increased P levels in both topsoil and subsoil and also had a positive effect on yield and shoot growth. Evidence of a P/K antagonism was encountered. Apparently, little P fixation occurred, and it was found that less than 9 kg P/ha/yr was needed on this P-deficient soil to ensure optimum yield and growth. Potassium fertilization increased K levels in the soil as well as yield and shoot mass. A fertilization level of less than 45 kg K/ha/yr was needed on this soil with its marginal initial K content and a soil norm of 50 mg/kg seemed appropriate for K.