Possible Use of Renewable Industrial By-products in Environmentally- Friendly Agricultural Production Brigitta Tóth 1+ , László Lévai 1 , Imre Vágó 2 and Szilvia Veres 1 1 University of Debrecen – Institute of Crop Sciences, Department of Agricultural Botany and Crop Physiology 4032 Debrecen, Böszörményi s. 138 Hungary 2 University of Debrecen – Department of Agricultural Chemistry and Soil Science, 4032 Debrecen, Böszörményi s. 138 Hungary Abstract. The aim of our study is to provide on overview of selected wastes (sewage sludge, lime sludge, compost) on the physiological parameters of sunflower (Helianthus annus L. cvs. Arena). The filtrates of the examined materials were added to a nutrient solution. The dry matter accumulation of the shoots and roots, the relative chlorophyll contents and the contents of elements were measured of plants that were grown on a nutrient solution. We concluded that the examined wastes may have dangerous effects on the ecosystem, because they contain several harmful elements for plant development. Keywords: crop production, environmental protection, industrial by-products 1. Introduction While worldwide data on emission of heavy metals from natural sources are particularly scarce, a summary of a literature survey has been prepared. Windblown dusts and volcanic eruptions are of particular relevance to ecosystem inventories and budgets of heavy metals. Marine aerosols and forest fires also exert a major influence on many environments. While the long-range transport of dust particles, particularly from the Sahara, has recently received considerable attention [1] the transport of dust particles originating in Asia and elsewhere to the Pacific, Arctic and Antarctic has also been investigated [2]. Climate change may bring about increased aridity to large areas of Europe. Higher temperatures, larges water deficits and high light stress are likely to occur in conjunction with elevated levels of CO 2 . These changes raise the question whether a high CO 2 concentration in the atmosphere can compensate for the decrease in carbon gain under water-stressed conditions. The processes which determine dry matter production and the ways they are affected by soil water deficits are discussed. It is now well established that in most species and under most circumstances stomata is the main limiting factor to carbon uptake under water deficit; the photosynthetic machinery being highly resistant to dehydration. However, when other stresses are superimposed, a decline in photosynthetic capacity may be observed. In the short term, under drought conditions, an increase in CO 2 in the atmosphere may diminish the importance of stomata limitation for carbon assimilation inhibiting photorespiration, which might otherwise result in significant losses in plant production under stress conditions. However, in the longer term though, a negative acclimation of photosynthesis appears to occur in many species, an explanation for which still needs to be clearly identified. Similarly, the effects of extended exposure to elevated CO 2 under arid conditions are not known. Plant production is more closely related to the integral of photosynthesis over time and total foliage area than to the instantaneous rates of the photosynthetic process. Water deficits result in a decrease in foliage area biomass and, therefore, in productivity. On the other hand, the increase in air temperature may result in more + Corresponding author. Tel.: + 003652 512900 E-mail address: btoth@agr.unideb.hu 124 2011 International Conference on Environment and BioScience IPCBEE vol.21 (2011) © (2011) IACSIT Press, Singapore