Evaluation of the efficiency of phosphorus uptake by rice and beans cultivars related to root architecture, using the isotope dilution technique with 32P and 33P

Abstract

The low availability of phosphorus (P) in soil is a major constraint to the optimal development of plants in tropical regions. Many studies have demonstrated the need to improve the use of P, especially in areas where concentrations of P in the soil are considered low due to soil genesis and / or insufficient application of fertilizers. Plants originating in or adapted to soils with low P concentrations tend to develop more effective mechanism of roots exploration, increasing the length and density of the same. Thus, the objective is to this work was to evaluate the influence of the architecture of the root crops of rice and beans related to the efficiency of P uptake in Cerrado soils, seeking to improve the capacity of the plant to absorb P in tropical soils. This project will be developed in three phases I and III in greenhouse, and II in field conditions. All procedures will be adopted for each phase for the two crops: rice and beans. The Phase I experiments will be conducted with the objective to select among 20 cultivars of upland rice and 20 varieties of beans, efficient materials to absorb P, using the technique of isotope dilution of the 32P. The Phase II experiments will be the objective of evaluating and characterize root architecture of the same 20 cultivars of upland rice and 20 varieties of beans, and calculate the nutritional efficiency of these cultivars, and compare with the experimental results of phase I. Based on the results of the experiments of Phases I and II experiments in phase III, intended to evaluate the availability of P stimulates the modification of root architecture along the soil profile by double staining of the soil profile with radioisotope 32P and 33P. (AU)