Integrated Management of Slow- release Nitrogen Fertilizer Types and Rates for Wheat Production under Middle Nile Delta Soil Conditions

In light of the state’s trends towards sustainable agricultural development and achieving self-sufficiency in food, especially wheat, as it is considered a strategic crop in Egypt. Also, in order to preserve the environment and human health as well as save the material and moral losses resulting from the excessive use of urea as a nitrogen fertilizer. So, two field experiments were conducted at the experimental farm of Tag El-Ezz, Agricultural Research Station (30o 59\ N latitude, 31o 58\ E longitude´), ARC, Dakahlia Governorate, Egypt, during two winter successive growing seasons of 2022/2023 and 2023/2024. The experiments evaluated the efficiency of two different mineral slow- release nitrogen fertilizer sources: urea formaldehyde (UF), sulfur coated urea (SCU) and two organic amendments: compost (C) and vermicompost (VC) individually or in combination using different rates comparing with usual fertilizer urea (U) at recommended nitrogen fertilization rate (178.5 kg N ha-1) for wheat production under alluvial soil conditions. As well as, tracking the fate nitrogen in the soil during different wheat growth stages and effect of treatments on some chemical properties of experimental soil after harvesting.

The acquired results demonstrated the ability to apply slow-release nitrogen fertilizers in mineral or organic form to sustain agricultural output and preserve environmental quality. Combination of mineral and organic fertilizers achieved the best growth and improved physiological functions and chlorophyll formation. Combination treatment of urea formaldehyde (UF) 50% of nitrogen recommended dose (NRD) and vermicompost (VC 25% of NRD) (treatment N9) increased vegetative growth parameters and chlorophyll content comparing with the other treatments. Treatment N9 increased chlorophyll a by 4.96 and 4.47% as well as increased chlorophyll b by 3.21and 3.89% in both seasons, respectively comparing with the control treatment (usual urea at 100% NRD).

Application of sulfur coated urea (SCU 50% NRD) in combination with vermicompost (VC 25% NRD) (treatment N11) was the superior treatment application at harvest stage. Treatment N11 increased yield by 11.63 and 11.45% in two successive seasons respectively comparing with the control treatment (N1). Regarding to the soil, all slow-release nitrogen fertilizer treatments had a significant impact on the soil's nitrogen content at various interval phases and on chemical soil properties i.e. pH, Ec and organic matter content.

From an economic point of view, SCU at 50% NRD combined with compost at 25% NRD (N10 treatment) applied treatment listed the highest net return (7807.4 and 24107.4) as well as BCR (1.18 and 1.37) in both growing seasons , respectively . So, it could be an excellent alternative to usual urea for increasing production and farmer revenue.

Finally, the results show that treatments involving the interaction of slow-release fertilizers from both organic and mineral sources have a long-term impact in terms of reducing fertilization rates, increasing wheat productivity, and improving soil properties that have been degraded as a result of agricultural practices. Furthermore, my production and specifications are compliant with food safety requirements and agricultural quarantine regulations for export, which aligns with the state's initiatives to promote sustainable agriculture.