OTKA ID number: T 038046
Project leader: Csillag Julianna
Name of institution: MTA Talajtani és Agrokémiai Kutató Intézet – Research Institute for Soil Science and Agricultural Chemistry of the HAS
address: 1022 Budapest, Herman O. út. 15.
Agronomic effectiveness and environmental risks of phosphate rock application
In Hungarian agricultural practices mainly superphosphates are used for P fertilization, consequently, very few data are available on reactive phosphate rocks (PR), which are widely applied on acid soils throughout the world. The goal of our research is to evaluate the agronomic effectiveness and environmental risks of the direct application of various PR as fertilizers on acid soils in Hungary.
The quantitative evaluation of the P availability from PR will be provided on the basis of a wide spectrum of soil and plant analyses and dynamic simulation.
We pay great attention to study the bioavailability and polluting effects of Cd and other heavy metals in soils amended with PR; their mobilization in soil and accumulation in edible plant parts.
After the determination of the P content, P solubility, specific surface area and heavy metal concentrations of the different P sources, the capacity of the PR to compensate high acid loads will be assessed in order to describe the effects of acidification on the mobilization of their contaminants.
Pot experiments will be carried out by application of various PR on acidic clay loam and sandy soils with spring barley and red clover crops.
The impact of P sources and P rates on easily soluble soil P contents in the pot experiments, determined by various P test methods will be studied. The total and Lakanen-Erviö extractable heavy metal content of the soils, as well as their concentrations in the soil solution will be determined. The effect of the different P sources and P rates on crop yield, P content, concentration of potentially toxic elements in the tissues and on morphometric and ecophysiological parameters measured on shoots and roots, as well as arbuscular mycorrhiza infection will be also analysed.
The bioavailability of rock phosphates and the processes by which plant can influence the rate of PR dissolution will be studied by measurements and dynamic simulation.
By this research we intend to provide information for the comparative environmental qualification of the acidic superphosphates and the basic phosphate rocks as a promising solution for P application on the acid soils of Hungary.