Compost and Biostimulants versus Mineral Nitrogen on Productivity and Grain Quality of Two Wheat Cultivars

To reduce the environmental pollution, this study was designed to test the effect of using compost and biostimulants as total or partial replacement for mineral nitrogen on productivity and grain quality of two wheat cultivars. Two field experiments were conducted in the Desert Experimental Station, Cairo University located at Wadi El-Natroon, Egypt during two successive seasons (2016/2017 and 2017/2018). A split-split-plot design in a randomized complete block arrangement was used. Four fertilizer treatments (100% mineral nitrogen as control, 100% compost, 75% compost + 25% mineral nitrogen and 50% compost + 50% mineral nitrogen). Four levels of biostimulants foliar applications (control, 0.75 L ha−1, 1.13 L ha−1 and 1.5 L ha−1). Treatments were tested on two wheat cultivars (Egyptian cultivar, Gemmiza-10 and Nigerian cultivar, LacriWhit-4). Results indicated that, the treatment of 50% compost + 50% mineral nitrogen fertilizer along with 1.5 L ha−1 of biostimulants (VIUSID® agro) significantly increased the grain yield of both wheat cultivars, LacriWhit-4 and Gemmiza-10 (4.44- and 4.53-ton ha−1, respectively). The increase of grain yield was 0.9- and 1.36-ton ha−1, respectively. The treatment of 100% compost significantly increased protein, crude fiber, total sugars, Mg and Mn contents in grain while the treatment of 100% mineral nitrogen fertilizer significantly increased ash, total phenols, P and Ca contents in grain. Replacing nitrogen fertilization with compost significantly increased ether extract and carbohydrates content of the Nigerian cultivar grains while N, K and Fe contents were increased in the grains of both tested cultivars. The foliar application of biostimulants (VIUSID® agro) at different levels significantly increased protein, carbohydrates, total sugars, P, K, Ca, Cu and Zn contents. It can be concluded that replacing mineral nitrogen fertilizer with a combination of compost and mineral nitrogen (50% compost + 50% mineral nitrogen) along with 1.5 L ha−1 of biostimulants (VIUSID® agro) is recommended for the enhancement of productivity and grain quality of wheat while reducing environmental pollution.