Nitrogen Use Efficiency in Sandy Soil Using 15N Tracer Technique

The effect of water regime and fertilizer-N application rate and modality of application were studied in order to identify the most proper and effective combination of the above-studied variables that provides a satisfactory spinach yield and minimizes the use of chemical nitrogen fertilizers, to save the surrounding environment and to achieve good water saving. Water requirement and Nitrogen fertilizer are two factors notably affects the growth and yield of Spinach crop. So, any delay in irrigation, thinning or insufficient water supply and nitrogen fertilizer would negatively affect the growth and yield. Also frequent or excessive amount of water and nitrogen fertilizer would lead to increase the losses of water and nitrogen fertilizer. So, it is important to identify the educate amount of irrigation and nitrogen fertilizer need to maximize growth, and quality of the spinach crop. Drip irrigation system together with proper water regime and good fertilizer application practices is considered to be a useful management practice that could be applied to improve the sandy soil productivity.

Dr. Lamy HAMED is an Assistant Prof. of Fertility and Fertilizers at Soil and Water Dept., Fac. of Agri., Cairo Univ., Egypt. He holds a Master Degree in Land and Water Management, Bari, Italy. Master in Natural Resources Evaluation, Florence, Italy. He obtained his doctorate in Agricultural and Environmental Sciences from Milan University, Italy.