Response of greenhouse cucumber to mineral fertilizers on a high phosphorus and potassium soil

Abstract

Abstract The response of greenhouse cucumber (Cucumis sativus L. cv. Lolita) to nitrogen (N), phosphorus (P) and potassium (K) fertilizers on a soil high in available P and K was studied during 1986. The greenhouses were located in the Beqa Valley, central Lebanon, and their soil chemical properties before planting were: NO3‐N = 52 ppm, P(NaHCO3 ext.) = 100 ppm, K (ammonium acetate ext.) = 650 ppm, ECe = 1.6 dS/m, pH = 7.5. Nitrogen at 200 kg/ha, P at 85 kg/ha and K at 150 kg/ha were applied in the following combinations: N, N+K, N+P+K and an unfertilized control. The rates were split into four equal weekly applications starting on the fourth week after transplanting the seedlings to the greenhouse. The treatments were applied through the drip irrigation system of the greenhouses. Fruit yield over the two months of harvest was highest in plants receiving N alone, which yielded 57 ton/ha. Yields of the plots receiving N+K, N+P+K and the control were 55.0, 54.0 and 39.5 ton/ha, respectively. Yield during the first month of harvest was comparable in all fertilized treatments and was substantially higher than the control.