© by PSP Volume 28 – No. 11A/2019 pages 8814-8822 Fresenius Environmental Bulletin 8814 EFFECTS OF PHOSPHOGYPSUM WASTE APPLICATION ON CORN (ZEA MAYS L.) YIELD AND NUTRIENT CONTENTS Ayhan Horuz 1,* , Metin Turan 2 , Guney Akinoglu 1 , Cengiz Ozcan 3 , Adem Gunes 4 , Ahmet Korkmaz 1 , Yilmaz Kaya 5 , Nurgul Kitir 2 , Sevinc Adiloglu 6 , Sefik Tufenkci 7 , Aydin Adiloglu 6 , Mehmet Rustu Karaman 8 , Ekrem Ozlu 9 1 Ondokuz Mayis University, Faculty of Agriculture, Department of Soil Science and Plant Nutrition, Samsun, Turkey 2 Yeditepe University, Faculty of Engineering, Department of Genetics and Bioengineering, Istanbul, Turkey 3 Directorate of Food Agriculture and Animal Breeding, Nevsehir, Turkey 4 Erciyes University, Faculty of Agriculture, Department of Soil Science and Plant Nutrition, Kayseri, Turkey 5 Ondokuz Mayis University, Faculty of Agriculture, Department of Biotechnology, Samsun, Turkey 6 Tekirdag Namik Kemal University, Faculty of Agriculture, Department of Soil Science and Plant Nutrition, Tekirdag, Turkey 7 Yuzuncu Yil University, Faculty of Agriculture, Department of Soil Science and Plant Nutrition, Van, Turkey 8 Afyon Kocatepe University, Department of Medical and Aromatic Plants, Afyon, Turkey 9 Department of Soil Science, University of Wisconsin-Madison, Madison, WI, USA ABSTRACT The transformation of agro-industrial wastes into value-added commodity is among the best approches to a greener and more sustainable future. The aim of in this study was to examine the effects of phosphogypsum waste (PGW) as fertilizer to improve yield and nutrient content in the grain, stem and leaves of corn (Zea mays L.). A random- ized experiment via a complete plot design was applied using four different triplicated doses of PGW (0, 1, 5 and 10 tons ha -1 ). It was shown that improvement in corn yield was proportional to the increase in PGW dose, corresponding to 46.19%, 38.76% and 39.65% for 1, 5, and 10 ton ha -1 of PGW, respectively. A 5.85 ton ha -1 PGW dose was optimal in yielding a 8.63 ton ha -1 of corn despite a 8.26 ton ha -1 the production yield using 5 ton ha -1 PGW, as the latter was statistically borderline sig- nificant. The approach adopted here also yielded corns with higher macro- and micronutrient con- tents compared to the control. The analysis of vari- ance data illustrated that the improved contents of N, P, K, Ca, Zn and B per 1 ton ha -1 , and Mg per 5 ton ha -1 were also significant (P<0.05). It can be construed that the recommended dose of PGW as fertilizer between 1−5 tons ha -1 can lead to substan- tial improvements in yield and nutrient contents in corn. KEYWORDS: Phosphogypsum waste, grain yield, leaf, stem, nutrient contents, Zea mays L. INTRODUCTION Corn (Zea mays L.) is one of the world’s most important silage crops owing to high production yield and palatability in comparison to other forage crops, as well as providing a large amount of ener- gy and protein in the animal diet [1]. According to recent statistics, the agricultural area devoted to corn plantation is 682.000 ha per annum, constitut- ing ⁓ 4% of cereal cultivation land in Turkey [2]. However, the quality and yield of corn is very much affected by a combination of several factors, for instance, environmental, genetic, and cultural dy- namics. The gradual rise in demand for corn is a matter of concern as it has elevated the cost of silage and grain production [3]. This issue warrants the attention of the agricultural and scientific com- munity, as simply leaving the ruminant livestock grazing on natural pastures is no longer adequate due to low levels of nutrition, more so during dry seasons [4, 5]. In fact, the livelihood of farmers very much depends on the amount of nutrients that are fed to their livestock as this will, in turn, affect the final quality and price of the produced meat. The elevated production costs have somewhat to do with the decline in soil fertility as a conse- quent of rigorous agricultural land use that severely depletes the nutrients in soil. Nevertheless, corn farming productivity can be improved by supple- mentation of soil with nutrients such as nitrogen and phosphorus. It is a two-prong nutritional boost to promote forage yield of corn, and its crude pro- tein content, in addition, the latter forms an integral portion of nucleic acid and essential for vegetative growth [6], seed, fruit quality, alongside good crop formation and maturation. The form of native soil phosphorus, inter alia different rates and type of applied phosphorus, as well as soil reaction are factors responsible for phosphorus availability to