Synthetic nitrogen fertilizers can contribute to environmental hazards. Moreover, their manufacturing is an energy-intensive process which causes greenhouse gas emissions, which can lead to climate change. Therefore, it should evaluate the possibility to use organic sources such as Azolla as a partial substitute for synthetic nitrogen fertilizers in cultivation, as this may reduce the cost of fertilizer inputs, and promote sustainable agriculture. So, a field trial was carried out in the Tag El-Ezz Experimental Farm (30°56' 12.88" E longitude and 31°31' 47.64" N latitude) during seasons of 2021/2022 and 2022/2023 to assess the additive of nitrogen recommended dose (NRD=178.6 kg N ha-1) as combined treatments of urea (46.5%N) as mineral nitrogen source and Azolla (4.0 %N) as organic nitrogen source. Also, the exogenous application of zinc (zinc sulfate, 22.8% Zn) and copper (copper sulfate, 21.8 %Cu) was evaluated. The tested plant was wheat (Cv. Giza 171). The nitrogen treatments [T1: 100% of NRD as urea (control),T2:75% of NRD as urea+25% of NRD as Azolla,T3:50% of NRD as urea+50% of NRD as Azolla, T4: 25% of NRD as urea +75% of NRD as Azolla and T5: 100% of NRD as Azolla] represented the main plots, while exogenous application of the studied elements [F1: control (without spraying),F2:Zn (at rate of 200 mgL-1) and F3: (Cu at rate of 20 mgL-1)]  represented the sub main plots. The findings illustrate that wheat plants grown under T2 treatment had  the highest values of growth performance (e.g., fresh and dry weights and total chlorophyll), yield and its components (e.g., grain yield, spike length and weight of 1000 grain) and biochemical traits (e.g., carbohydrates and total protein) compared to the corresponding wheat plants grown under other  studied N treatments, as T1 treatment (control) came in the second order followed by T3 treatment, while T4 and T5 treatments came in the last order, respectively. Regarding the external applications, the cu foliar application was the superior treatment followed by Zn treatment, while the control treatment came in the last order. Generally, the maximum values were recorded under combined treatment of (T2xF3). On the other hand, some soil fertility parameters like A-N, A-P and A-K were affected due to all studied treatments. Finally, it can be concluded the possibility of using Azolla as a partial substitute for synthetic nitrogen fertilizers. Also, the obtained results confirm the vital role of both Zn and Cu in wheat plants.

Two field experiments were conducted at the Experimental Farm of TagEl-Ezz , Dakahlia governorate (30° 59\\ N latitude, E 31° 58\\ longitude) ,ARC, Egypt during the two growing summer seasons of 2020 and 2021 as sake of studying the possibility of partially substituting for the amount of inorganic NPK fertilizers required for maize plants using compost and/or vermicompost and their effects on growth, yield and nutrients uptake of maize plants (Single cross 10 variety) under the alluvial soil conditions. Experiments were laid out in split plot design with three replicates. However, main plots were affected for four rates of inorganic NPK fertilizers i.e.; without, 50%, 75% and 100% of the recommended dose (RD)) whereas, four organic fertilizers namely without, compost (C); (5 ton fed-1), vermicompost (VC); (0.5 ton fed-1) as well as half compost and half vermicompost (mix)) were randomly distributed in the sub plots. Results showed that: 1-Application of inorganic NPK fertilizers at 100% RD recorded the highest values of growth parameters, yield and nutrients uptake by maize grains in the two investigated seasons 2-Using organic fertilizers i.e. compost and /or vermicompost caused a significant effect on all growth parameters, yield and nutrients uptake. In this respect, V.C. attained the superiority impacts followed by mix and lately C compared with control (without adding NPK fertilizers). 3-The addition of inorganic NPK fertilizers at 100% RD and organic V.C. had positive impacts on maize growth parameters, yield and nutrients uptake better than the application of inorganic NPK fertilizers at 100% RD singly under the two investigated seasons. 4-Dual application of inorganic NPK fertilizers at 100% RD and organic C treatment application achieved the highest values of available NPK in the soil post harvesting. 5-Economically using inorganic NPK fertilizers at 75%RD and C recorded the highest net return and benefit cost ratio (BCR). So, it could be a good alternative to other treatments, save 25% of inorganic NPK fertilizers and viable option for enhancing crop yield and farmers income.

Collectively, the challenges aim to accelerate the development of innovative fertilizer product technologies and to increase the use of existing enhanced efficiency fertilizers sources (EEFS) like slow release fertilizers (SRF) as an example for increasing crop yields and reducing environmental impacts to air, land and water. Two field experiments were carried out at Experimental Farm of Tag El-Ezz, Agricultural Research Station (30 o 59 \ N latitude, 31 o 58 \ E longitude´), Agriculture Research Center (ARC), Dakahlia Governorate, Egypt. Completely randomized blocks design (CRBD) with three replicates was used during the two winter and summer successive growing seasons 20۲۰/21 and 2021 to study the effect of three different slow release nitrogen fertilizer (SRNF) sources 1-sulfur coated urea (SCU), 2-urea formaldehyde (UF) and 3cement coated urea (CCU) with different fertilization rates (100,125 and 150 % from the recommended dose) comparing with conventional urea (CU) under recommended fertilization rate for wheat and corn crops respectively (75 and 120 kg N fed -1 ) on growth, yield and its components of wheat (Triticum aestavium L.) cv. Misr1 during the winter season. As well as studying the residual effect of (SRNFs) with half additional application does of conventional urea to each plot on maize (Zea mays L.) var. (Tri Cross 360) growth, yield and its components. Available soil N in the experimental plots was determined during the growing seasons along the two experiments. The obtained results indicated the ability to use new age technologies as enhanced efficiency fertilizers (EEFS) like slow release fertilizers (SRFs) to sustain crops yield and maintain environment quality.SRNFs applications gave the highest values of vegetative growth, yield and its components of wheat plant compared to conventional urea. Raising rate of N fertilizer caused an increase in all studied parameters. SCU using at 100% fertilization rate was the superior SRNF using at the same rate where it increased ChllC a+b and BY by 31.23 and 19.95%, respectively, as well as it gave the highest grain nutrients concentration and protein content by 2.35% for N; 0.289% for P; 1.38% for K and 13.51% for protein comparing with CU using at 100% fertilization rate. The highest residual N (mg kg -1 ) in the soil after wheat harvesting was recorded with cement coated urea (CCU) and the same trend continuous to maize post harvesting. Thus the residual of CCU using at 100% fertilization rate + 50% CU increased maize ChllC a+b and BY by 36.40 % and 7.27%, respectively as well as it gave the highest values of maize grain content from N (2.09%), P (0.134%), K (1.46%) and oil content (5.20%) comparing with CU using at 100% fertilization rate. Economically, we advised farmer using SCU at 100% fertilization rate for one crop and using CCU at 100% +50 % CU recommended fertilization rates for cropping sequence.