Azumah, S. , Tindjina, I. , Obanyi, S. , Wood, T. (2017), 'Productivity Effect of Urea Deep Placement Technology: An Empirical Analysis from Irrigation Rice Farmers in the Northern Region of Ghana', World Academy of Science, Engineering and Technology, Open Science Index 123, International Journal of Agricultural and Biosystems Engineering, 11(3), 200 - 205.