INFLUENŢA NUTRIŢIEI CU FOSFOR ŞI FIER ASUPRA DEZVOLTĂRII NODOZITĂŢILOR LA PLANTELE DE SOIA ÎN CONDIŢII DE SECETĂ TEMPORARĂ

Abstract

Low-phosphorus availability and water stress are main environmental constraints of soybean growth and nodulation. A pot experiment was carried out to investigate the effect of phosphorus (P) and iron (Fe) application on nodulation in water-stressed soybean plants. Phosphorus (KH2PO4) and Fe (FE-EDTA) were applied in soil in dose 100 mg per kg of soil and 5 mg respectively. One set of plants was subjected to suboptimal water regime (35% WHC) at flowering stage for 12 days. Another set served as control was grown at normal moisture of soil (70 % WHC). Nodulation and plant growth were significantly decreased by low nutrient supply and drought. Combined effect of drought and P deficiency decreased most the growth of nodules and plants of both cultivars Zodiac and Licurici. Supplemental P nutrition alone or in combination with Fe significantly increased nodules biomass irrespective of soil water regime. However, its effect was more pronounced on cultivar of Licurici. It is concluded that harmful effects of water deficits can be attenuated by adequate nutrition with P and Fe of soybean plants.