The concept of Integrating Aquaculture with Agriculture (IAA) is considered the right path towards achieving sustainable agriculture in semi and arid areas. With the increase of global water scarcity, the double utilization of water for both fish and crop production is gaining more attention since it ensures maximizing the productivity of every unit of water used. This study investigated the effect of fish effluent irrigation on the herbage growth, essential oil content, and composition of Origanum syriacum L. The experiment followed a randomized complete design of three irrigation treatments with three replicates, i.e., control with 100% chemical fertilizers (CT), full irrigation with fish effluent (FT), and the mixed treatment (MT) with 50% CT and 50% FT. Study findings showed that FT reached 49 branches/plant, gained maximum plant height (58.8cm), and highest fresh and dry herbage yield reaching 17.76 and 6.722 tons ha-1, respectively, in the second cut. Essential oil content reached the maximum in FT at 64.02dm3 ha-1 and 143.5dm3 ha-1, while the lowest in CT at 15.95dm3 ha-1 and 109.33dm3 ha-1 for the first cut and second, respectively. Carvacrol was the main constituent of the excreted essential oil, representing a maximum of 80.87% for FT in the first cut and 74.69% for MT in the second cut. It was closely followed by p-Cymene (10.75% - CT, 6.38% - FT) and γ-Terpinene (5.06% - CT, 8.49% - FT) for the first and second cut respectively. The importance of these major chemical components stems from their use in both the food and pharmaceutical industries.

The vast diversity of microalgae imposes the challenge of identifying them through the most common and economical identification method, morphological identification, or through using the more recent molecular-level identification tools. Here we report an approach combining enrichment and metagenomic molecular techniques to enhance microalgae identification and identify microalgae diversity from environmental water samples. From this perspective, we aimed to identify the most suitable culturing media and molecular approach (using different primer sets and reference databases) for detecting microalgae diversity. Using this approach, we have analyzed three water samples collected from the River Nile on several enrichment media. A total of 37 microalgae were identified morphologically to the genus level. While sequencing the three-primer sets (16S rRNA V1-V3 and V4-V5 and 18S rRNA V4 region) and aligning them to three reference databases (GG, SILVA, and PR²), a total of 87 microalgae were identified to the genus level. The highest eukaryotic microalgae diversity was identified using the 18S rRNA V4 region and alignment to the SILVA database (43 genera). The two 16S rRNA regions sequenced added to the eukaryotic microalgae identification, 26 eukaryotic microalgae. Cyanobacteria were identified through the two sequenced 16S rRNA regions. Alignment to the SILVA database served to identify 14 cyanobacteria to the genera level, followed by Greengenes, 11 cyanobacteria genera. Our multiple-media, primer, and reference database approach revealed a high microalgae diversity that would have been overlooked if a single approach had been used over the other.

Potato (Solanum tuberosum) is an important food crop. However, intensive cultivation has led to increased reliance on chemical fertilizers, raising environmental and economic concerns. One of the concerns in potato plantations is phosphorus, which often exhibits low availability due to leaching and poor use efficiency, coupled with rising fertilizer production costs. This study investigates the agronomic and economic impacts of using natural rock amendments combined with plant growth-promoting rhizobacteria (PGPR) as sustainable alternatives to chemical fertilizers on the yield and tuber quality of potato. A field experiment assessed three treatments: conventional chemical fertilizers (T1), reduced chemical fertilizers combined with PGPR (Bacillus megaterium, Bacillus mucilaginosus, and Azotobacter) (T2), and natural rock amendments of potassium feldspar and rock phosphate combined with PGPR (T3). Results showed that T2 and T3 demonstrated improved tuber quality compared to T1, with T3 achieving the highest starch content (314.05 mg/g FW) and reduced sugar content (102.03 mg/g FW). Furthermore, T3 improved soil quality after the growing season, showing higher phosphorus and potassium availability compared to T1. Economically, T3 reduced operating costs by 11% and achieved the highest yield (42 tons/ha). The return on investment for T3 reached approximately 79.48% (USD 3988/ha), with a 40.9% profit increase compared to T1 (USD 2460/ha) These findings confirm that integrating PGPR with natural rock fertilizers offers a cost-effective and durable alternative to conventional fertilization practices, enhancing productivity and profitability while providing significant opportunities for achieving the Sustainable Development Goals and promoting long-term soil sustainability.

Identifying microalgae biodiversity is essential to unleashing the diverse potential applications for microalgae. The aim of the chapter is to define the various tools and methodologies possible for revealing microalgae diversity. Identifying microalgae from natural environments, hotspots, and extreme environments enables us to isolate naturally tolerant species that may thrive and exhibit unique characteristics. Identifying microalgae will enable researchers to uncover new applications for these versatile organisms, including biofuel production, wastewater treatment, and pharmaceutical development. Hence, it is crucial to define the different possible identification approaches, beginning with the sample collection protocols and extending to the identification methods employed to determine the diversity of microalgae in an ecosystem.

Pearl millet (Pennisetum glaucum) is a widely cultivated C4 cereal crop in tropical and subtropical regions, serving as a food and feed source in developing countries across Africa and Asia. Despite its agronomic importance, research efforts aimed at developing improved millet varieties under the current climatic changes remain limited, particularly in Africa, including Egypt. This study aimed to establish an efficient regeneration system for the “Shandaweel-1” Egyptian pearl millet variety using immature inflorescences as explants. Six different callus induction media (CIM) treatments were evaluated for their effects on somatic embryogenesis, callus type, vitrification rate, and regeneration efficiency. Among the tested treatments, Murashige and Skoog (MS) media additionally supplemented with 1.0 mg L⁻¹ of l-proline, 1.0 mg L⁻¹ of l-asparagine, 10 mg L⁻¹ of silver nitrate (AgNO₃), 0.32 mg L⁻¹ of copper sulfate (CuSO₄), 1.0 mg L⁻¹ of 2,4-dichlorophenoxyacetic acid (2,4-D), and 0.5 mg L⁻¹ of 6-benzylaminopurine (BAP) produced a high callogenesis rate (93%) and the highest regeneration efficiency (47.6%). The combination of l-proline and l-asparagine enhanced the callus quality and regeneration potential more effectively than casein hydrolysate alone, whereas AgNO₃ addition did not have any significant impact on the vitrification or callogenesis rates. This study represents the first successful establishment of an in vitro regeneration system for an Egyptian pearl millet variety, providing a valuable platform for future genetic modification aimed at enhancing stress resilience and crop productivity.