Subsurface drip irrigation and urea phosphate fertigation for vegetables on calcareous soils

Abstract

Abstract Drip irrigation lines installed at 5 cm (shallow) or 15 cm (deep) below the soil surface and furrow irrigation were compared for vegetables grown on calcareous desert soils. Urea phosphate (UP) fertilizer (17–44–0) was injected twice in the drip irrigation lines during the growing season. Yields were compared to preplant fertilized and unfertilized furrows. Fall cabbage (Brassica oleracea var. capitata L.) gave comparable yields under the different irrigation treatments with the drip treatments using half the water used by the furrow treatment. Cabbage yield increased in all fertilized treatments as compared to the unfertilized furrow. Petiole P and NO3‐N concentrations were higher from the drip than from the furrow treatments. Zucchini squash (Cucurbita pepo L.) had the highest yields under deep drip and fertilized furrow treatments, with the deep drip using half the water and P rate used by the furrow treatment. The deep drip increased squash yield by 34% over the shallow drip. The unfertilized...