INFLUENCE OF PARTIAL ROOT-ZONE DRYING ON WATER USE EFFICIENCY AND PHOSPHORUS UPTAKE OF CORN (ZEA MAYS L.) IN A GYPSIFEREOUS SOIL

Abstract

Pot experiment was conducted to study the alternate and fixed partial root zone drying on irrigation water use efficiency and phosphorus absorption efficiency of corn (Zea mays L.) in a gypsiferous soil during the spring growing season. The experiment included three irrigation techniques, which were conventional irrigation (C1), alternating partial root-zone drying (APRD) and fixed partial root-zone drying (FPRD), and three levels of phosphate fertilizer application (40, 80, 120 Kg h-1), for three stages of plant growth, jointing stage (40 days from planting), booting stage (60 days from planting) and maturing stage (105 days from planting). The experiment was carried out with a complete randomized design with nine replications. Yellow corn seeds variety DKC6664 were planted on 20/3/2020. During the aforementioned growth stages, the development of the root system and vegetative parts of corn plants were studied and the water use efficiency was calculated for each growth stage. Results showed a decrease in the ratio of root to the vegetative weight under the alternating and fixed root-zone drying for the three fertilization levels and the three-growth stage (jointing, booting, maturing). The conventional irrigation treatment gave a grain yield of 40.53, 51.44 and 57.71 g pot-1 for the fertilization levels of 40, 80 and 120 kg P h-1 with a significant difference compared to alternate and fixed partial root-zone drying treatments. Alternate partial root-zone drying give the highest water use efficiency of 0.90, 0.93 and 0.98 kg m-3. Higher values of phosphorus absorption was recorded with CI treatment. The phosphorus absorption was high in the jointing and booting stages of corn growth. Phosphorous reduced some of the negative effects of water shortage on plant growth and yield and the reason for an increase in water use efficiency.