Eco-Friendly Production of Maize Using Struvite Recovered from Swine Wastewater As a Sustainable Fertilizer Source (Report‪)‬

INTRODUCTION It is estimated that the present reserves of mined phosphate rocks is 7,000 million tons as [P.sub.2][O.sub.5], in which 40 million tons of P rock is used for fertilizer production and human consumption every year (Florida Institute of Phosphate Research, 2005). It is predicted that the demand for P will increase by 1.5% each year (Steen, 1998). So, it might be stated that the mined P rocks will be exhausted within 90 years, assuming a 1.5% annual increase of utilization. Shu et al. (2006) stated that all reserved P rock will be exhausted by the year 2090 as 1.5% increasing utilization trend, and currently there is no alternative sources of P for crop production (Sharpley, 2001). So, it is essential to develop an alternative source of P fertilizer for uniform crop and animal production.