Effects of application of organic amendments i.e, compost (COM), farmyard manure (FYM) and town refuse manure (TR) (at a rate of 5 Mg fed.-1 corresponding to 12 Mg ha-1) with or without different levels of N (i.e, 0, 60, 90 and 120 kg N fed.-1, corresponding to 0, 143, 215 and 286 kg N ha-1) in the form of urea on maize (Zea mays L. cv. Triple hybrid 310) grown on a saline-sodic loamy sand soil at Gelbana village, Northern Sinai Governorate, Egypt were studied during the two successive summer seasons of 2013 and 2014. The treatments were arranged in a randomized complete block design with three replicates. Soil content of available N, P, K, Fe, Mn and Zn increased whereas the electrical conductivity (EC dSm-1) and soil pH values decreased due to these treatments. The applied organic amendments and urea as well as their combinations, generally increased significantly all the growth parameters i.e. plant height, grain weight ear-1 and 100-grain weight and consequently grain yield in the two growing seasons. Values of N, P, K Fe, Mn and Zn uptake by maize plant increased significantly in both the growing seasons.
The highest values of apparent nitrogen recovery (ANR) were obtained due to the treatment T R + (90 kg N fed.-1) at the two growing seasons, however, the highest nitrogen agronomic efficiency (NAE) was obtained owing to the treatment consisting of COM + N at a rate of 60 kg N fed.-1. Proline content decreased with increasing N rate up to 120g N fed.-1; however, the highest proline content (5.94 g g-1 fresh weight) was obtained due to application of TR without urea fertilizer. In the contrary, total chlorophyll content increased with increasing N rate up to 120 kg N fed.-1 which resulted in the highest content of chlorophyll when this rate of N was accompanied with COM during the two growing seasons. The highest rate of N fertilization i.e., 120 kg N fed.-1 combined with TR or FYM compost was of the most superior effect on protein content and nutrient contents. This was found to be true for both 2013 and 2014 seasons.