Precision nutrient management—Impact on the environment and needs for the future

The inadequacies in plant nutrition and fertilizer application (dosage not according to the requirements; improper N‐P‐K ratio; lack of Ca, Mg and micronutrient supply; limited variety of fertilizers; problems related to storage, time of application, means of distribution; etc.) lead to serious environmental problems (e.g. soil acidification ‐> mobilization of potentially toxic elements: “chemical time‐bomb effect” P load of surface waters ‐> eutrophisation ‐> unfavourable changes in aquatic ecosystems, rapid silting‐up of canals and reservoires; nitrate pollution of drinking water resources ‐> human health problems; accumulation of toxic compounds from fertilizers; etc.) in many parts of the World, both in developed and developing countries. (Most of) these side effects ‐ however ‐ are not inevitable and uncontrollable consequences of fertilizer application. Precision nutrient management is the key task of sustainable agricultural development, economic biomass production and efficient environment protection. The objective of precision nutrient management is to satisfy the nutrient requirements of crops, without any environmental side‐effects. The main criteria of such a system, are:1. fertilizer application according to crop requirements (involving their nutrient uptake dynamics) and land‐site characteristics (climate, relief, moisture supply, nutrient status and other properties of soils);2. reduction of nutrient losses (surface runoff, leaching, volatilization, organic and inorganic immobilization);3. increase of the “efficiency” of soil nutrients, applied manure and fertilizers. The scientific preconditions of this system are adequate knowledge on the:•nutrient regime of soils: spatial and temporal variability of the various forms ("soluble”, “exchangeable”, “mobile”, and “available") of plant nutrients in soils [soil testing].•transport and transformation processes of plant nutrients.•nutrient requirements and nutrient uptake dynamics of various crops [plant analysis and plant physiology].•effect of plant nutrition on the biomass production.•actual and potential inputs of plant nutrition on the environment (soil, surface‐ and sub‐surface waters, biota, “food‐chain” up to human health). The technical preconditions are:•availability of a great variety of fertilizers applicable for various crops under different natural conditions and land management practices.•possibilities for uniform and'or differential fertilizer application according to the spatial variability of a given landsite.•possibilities for splitted fertilizer application according to the nutrient uptake dynamics of a given crop. The main task of the scientist ‐ extensionist ‐ farmer ‐ environmentalist community in the future will be:•ensuring the above‐mentioned preconditions.•broadcasting the present knowledge and providing the necessary help (education, extension and advisory service, technical assistance, etc.) to the land user.•establishment of proper society control mechanisms (legislation, financial policy and other economy regulations) to stimulate (or even press ‐ when and where it is necessary) the land users for sustainable land use, including precision nutrient management. The effective realization of these tasks guarantee simultaneously rational biomass production, a pleasant environment and a promising future.