Enhanced Organic Fertilizers as a Partial Alternative to Synthetic Fertilizers: A Sustainable Tool for Improving Maize Productivity and Soil Properties

Abstract

It is known that synthetic fertilizers cause environmental and health damage. In this research, various fertilization regimes were implemented with maize plant aiming to reducing reliance on synthetic fertilizers. The treatments were T1: Control1 (100% of NPK recommended dose RD as synthetic fertilizers), T2: Control2 (50% of NPK - RD as synthetic fertilizers), T3: 50% of NPK-RD as synthetic fertilizers + Compost1 (Wheat straw alone), T4: 50% of NPK-RD as synthetic fertilizers + Compost2 (Maize residues + FYM), T5: 50% of NPK-RD as synthetic fertilizers + Compost3 (Cotton stalks +microbial activator),T6: 50% of NPK-RD as synthetic fertilizers + Compost 4 (Banana residues + palm fronds + wood ash), T7: 50% of NPK-RD as synthetic fertilizers + Compost 5 (Bean residues + molasses + yeast). Before conducting the experiment, the five types of compost were analyzed, and the analysis revealed a clear variation in the properties of these composts. All studied compost were added to the soil at a rate of 35 m3ha-1 according to the studied treatments. Compost5 showed a potential advantage in terms of the expected impact on maize plant performance and soil health (total microbial count), as it contained a higher percentage of organic matter and available nutrients as well as low C/N ratio. Regarding plant performance at 60 and 90 days, the superior treatments was T7, which achieved the highest values of growth criteria (such as plant height, fresh and dry weights and leaf area), photosynthetic pigments (e.g., chlorophyll a & b and carotene), straw content of NPK and ear qualitative and quantitative traits (e.g., grain and biological yield, harvest index, weight of ear, ear length and diameter, No. seeds ear-1 and weight of 100 grain, grain content of protein and carbohydrates). The T6 came in the second order in terms of effectiveness followed by T5, T1, T4, T3 and T2, respectively. Concerning, the soil properties such as available NPK,CEC, OM and total microbial count, all types of compost positively affected these properties, as the order sequence from top effectives to less were T7> T6> T5> T4> T3> T2> T1. Finally, it is recommended to use compost5,4,3, to substitute partially Synthetic fertilizers by up to 50% as part of integrated plant nutrition management programs, as this approach achieves high productivity and lower costs. Furthermore, this approach represents a fundamental step toward reducing reliance on expensive synthetic fertilizers with negative environmental influences.