Samir A. Haddad

Organic farming could be a promising approach as an agricultural system utilizing available organic materials without retrogradation natural resources. In this study, the effect of four levels of compost (0, 12, 18, and 24 t/ha) on fenugreek plants (Trigoneila foenum-greecum) over two seasons (2021–2022 and 2022–2023) was investigated in combination with different planting timings on a sandy soil. A randomized complete block design with three replications was used for the experiment conducted at the Agricultural Experiment and Research Centre of Minia University, Egypt. The Results showed that fertilizing fenugreek plants with compost significantly increased the vegetative growth traits such as plant height, number of branches/plants and herb biomass. The highest values of soil organic carbon (SOC), 986.3 mg kg^-1, dissolved organic carbon (DOC), 21.l6 mg kg^-1, dissolved organic nitrogen (DON), 9.43 mg kg^-1, microbial biomass-C (59.67 mg kg^-1.), -N (24.88 mg kg^-1), -P (14.67 mg kg^-1), net bacterial [95.3 (×10⁵ cfu g^-1)] and fungi [74.32(×10⁴ cfu g^-1)] counts were obtained with 24t/ha of compost. Enzyme activities of dehydrogenase (DH), urease and β-glucosidase (βG) increased significantly as the compost rate increased. For planting dates, the beginning of October was the optimal time for fenugreek production in April. For sandy soils with low fertility under arid conditions, organic and inorganic fertilizer use will enhance crop quality and productivity, soil health and soil organic matter build-up.

Five isolates of Azotobacter were isolated from different locations in Minia Governorate - Egypt anddesignated Az1, Az2 Az3, Az4 and Az5. Az3 was found to be most tolerant isolate to NaCl. Bacterialviruses of Azotobacter (Az3) were isolated from soil samples collected from Minia Governorate. Twelvesingle plaques of Azotobacter phages, were isolated. Due to the similarity of the phage isolates in theiroptimum pH sensitivity to UV (260 nm), thermal inactivation point and host range the phages ofAzotobacter were classified into groups A and B. On the basis of electron microscope study, Azotobacterphages of every group were found to be similar in their size and morphology. Generally, the obtainedresults indicated that, the twelve isolates of Azotobacter phage belong to two types of phage. These twophage types were named Az 1, Az 2.

This study was carried out to investigate the effect of inoculation with Cyanobacteria, Azotobacter, and Azospirillum individually or in combination with different mineral-N levels on the growth of wheat plants. A pot experiment was conducted during two successive seasons (2021 and 2022) in the Department of Microbiology, Faculty of Agriculture, Minia University. Results revealed that inoculation with any of the used microorganisms generally encouraged the growth of wheat plants. Also, the treatment with 75 % N + any of the used microorganisms gained the highest plant hight, fresh and dry weight of the plant, highest total N, P, and K contents of the plants. The obtained results indicated that no significant differences in the studied measurements were observed between the treatment with 75 % N + any of the used microorganisms and the application of 100% mineral N. Such results may suggest that inoculation of wheat plants with cyanobacteria or diazotrophic bacteria may preserve nearly 25% of the mineral nitrogen required for wheat production. The most successful inoculum for wheat development was determined to be the mixture of the studied microorganisms, Moreover, all of the microorganisms that were used in this study showed promising biofertilizers for raising crop yields.

Among crucial factors that control flooding events are extreme climate, urban growth, and mismanagement. Islands in the Nile River have experienced successive cycles of flooding and drying due to recent rainy years in the Nile Basin countries. This paper focuses on the impact of floods on the amounts of ammonium-N released, total concentrations of heavy metals, enzyme activities, and microbial biomass (C and N) in flood soils of 11 Nile River islands. Field moist soils and their airdried counterparts were collected from the outskirts of the island and incubated for 15 days at 30 °C to be analyzed. Results reflected that the amounts of released NH₄-N were higher in airdried than in wet soils. The average hydrolysis rates of the studied six enzyme substrates were correlated significantly with organic C, organic N, microbial bio-mass C and N in the field moist soils. The highest correlation coefficients (r) were with rates of hydrolysis of substrates of asparaginase, amidase, and β-glycosaminidase. A significant intercorrelation between rates of hydrolysis of the six studied enzyme substrates and r values which range from 0.81 to 0.98. At 10 mmol kg⁻¹ soil, Co⁺², Cd⁺², Pb⁺², Cu⁺², Cr⁺³, and Ni⁺² inhibited the release of NH₄-N. Arginine hydrolysis was inhibited by the six heavy metals at 5 mmol kg⁻¹ soil; the most effective inhibitors were Pb⁺², Ni⁺², and Cr⁺³. Due to the complex soil enzymatic and organic nitrogen hydrolase activities that occur during floods, fertile fields on the Nile River islands should not be fertilized before the summer flood seasons, which will prevent contamination of the Nile River water and loss of its island soil fertility.

Biofertilizers and biocontrol agents have been improved for several decades as microbiological tools that can provide beneficial outcomes in the growth and health of plants. Two field experiments were performed in the Scientific Farm of the Horticulture Department, Faculty of Agriculture, Minia University, Egypt during the winter of 2022/2023 using clay loam soil. Control plots were treated with the recommended rates of mineral fertilizer of NPK (100%) without inoculation, while other plots were inoculated with Egyptian isolates of effective microorganisms (EMs) (a mixture of Azotobacter chroococcum and Azospirillium brasilense) and strains of Bacillus spp.; the biofertilizers were applied to the soil through mixing with irrigation water. For mycorrhizae, Glomus mosseae and Glamus fasiculatum isolation stock cultures were combined to create the mycorrhizal inoculum. The results showed that biofertilizers with 75% NPK were the best. Biofertilizers changed the properties of soil, increased its content of beneficial microorganisms, increased the total good quality production of onion and potato and decreased the stress of chemical pesticides and mineral fertilizers on crop growth and productivity.

Dual use of water for fish and crop production could be a promising approach to improve irrigation under arid conditions. A watercress pot study was carried out to assess the effects of irrigation by catfish and tilapia aquaculture water on the sandy soil properties as well as the growth parameters of watercress with various combinations of artificial NPK fertilizers at El-Minia Governorate of Egypt (28°18′16″ N latitude and 30°34′38″ E longitude). Catfish aquaculture water had the greatest phytoplankton abundance at 83,762 units (×10⁴/L), while the minimum number of phytoplankton existed in tilapia aquaculture water, recorded at 14,873 units (×10⁴/L). There were significant average changes that varied from 120 to 237 (×10⁴ cfu/mL⁻¹) in total bacterial counts in tilapia and catfish waters. Watercress growth quality parameters closely paralleled at all NPK application rates, indicating that the highest quality plants were produced in pots receiving 25% of the recommended levels and irrigated with catfish aquaculture water. Nitrate concentrations of watercress plants were determined under pollution levels established by the European Commission for leafy and tuber vegetables. In conclusion, the use of microbial and phytoplankton-rich aquaculture water to irrigate vegetables and as fertilizer can maintain a balanced soil ecosystem.

Peri-urban agriculture is becoming a potential step to promote sustainable and environmental food production systems. Our aim was to study the effect of biochar application at various rates on faba bean growth, cellulose decomposition, nodulation, and selected enzyme activities associated with carbon cycling in clay and sandy soils collected from peri-urban agricultural areas near the city of El-Minia, Egypt. To achieve this aim, incubation and pot experiments were conducted under controlled greenhouse conditions using clay and sandy soil. Among the studied treatments, using biochar at the rate of 3 kg/sq·m was the most effective soil amendment followed by biochar at the rate of 2 kg/sq·m. At 60 days of incubation, the count of cellulose-decomposing microorganisms reached a high level in both clay and sandy soil, and then decreased after 90 days, regardless of the biochar rate. The response of the cellulose-decomposer ratio (F_cd/B_cd) was positively correlated with biochar rates and incubation time. The obtained results showed significant increases in fresh and dry weight in clay soil compared to sandy soil. In any case, the use of biochar as a soil amendment enhanced soil health, soil microbial communities, and increased cellulose-decomposing microorganisms, thus improving faba bean nodulation and growth.

Biochar (BC) is a material that has many applications in agricultural and environmental activities. The aim of the study was to define the influence of BC produced in low-temperature pyrolysis from various organic waste materials, including one-month-old compost (OMOC), pine bark (PB), pine needle mulch (NM), pine cones (PC) and maple leaves (ML), on soil enzyme activity as well as its relation with organic matter properties. A 60-day incubation pot experiment was set up to investigate the influence of BC amendment on soil (S) characteristics. After incubation, we investigated the activity of soil enzymes, the content of available phosphorus (AP), potassium (AK) and magnesium (AMg), total organic carbon (TOC), total nitrogen (TN), dissolved organic matter (DOM) and its fractional composition (content and share of carbon and nitrogen of humic (CHAs, NHAs) and fulvic (CFAs, NFAs) acids and humin fractions). The effect of the amended biochars differed depending on the feedstock material. In general, the use of biochar enriched the soil with AP, AK and AMg increased the soil carbon stock, increased the intensity of nitrogen transformation and influenced the soil enzyme activity. OMOC and ML biochars significantly increased soil fertility, which was expressed by the high value of the CHA/CFA ratio.

Landfilling is the least desirable of waste management methods, but despite tightening legal regulations it remains among the most common. Assessing the impact of landfills on the soil environment is even more important when there are arable lands in their vicinity. Therefore, the study examined soils on and directly adjacent to a landfill. Soil samples were collected from eight points (S1–S8) on the landfill premises, and from one more (S9) and a control (C), both of which were outside the premises. The parameters analyzed were pH in KCl and the contents of: organic carbon (OC), total nitrogen (TN), available phosphorus (AP), potassium (K), magnesium (Mg), total iron (TFe), total manganese (TMn), available iron (AFe) and available manganese (AMn). The activities of alkaline (AlP) and acid (AcP) phosphatase and phosphorus microorganisms (PSM) were tested. The results of biological parameters were used to calculate the resistance index (RS). The soils were alkaline (pH in KCl 7.09–7.65 at S1–S8). Using the RS index values for AlP and AcP the resistance of the soils was: AlP > AcP. The negative values of RS for PSM in most cases indicate a heavy human impact on this parameter. The tested points were found to have been significantly affected by changes in the content of bioavailable P, K and Mg. The total content of tested trace elements in the analyzed soil material did not exceed the geochemical background value. The soil in a sector that had been closed off for two years (S2) showed the highest biological activity. The physicochemical and biological parameters used in the research show the scale of processes going on in the soil environment and the degree (or lack) of its negative exposure to the influence of municipal waste stored at the Municipal Waste Disposal Plant.

The current research aims to study the impacts of adding corncob biochar to a sandy soil irrigated with drainage water on wheat productivity, heavy metals fate, and some soil properties that reflect healthy soil conditions. This research consists of two separate experiments under field (lysimeters) and pot incubation conditions conducted on sandy soil irrigated with drainage water and treated with corncob biochar at the rate of 0.0, 1, 2, and 3% as mixing or mulching. Results specified that drainage water electrical conductivity value (5.89 dS m⁻¹) lies under the degree of restriction on use of “Severe”, indicating that nonstop irrigation with such drainage water may cause a severe salinity problem in soil in the long run. A comparison of heavy metal concentrations of biochar-treated soils with the control showed that total heavy metals had accumulated significantly in the topsoil layer. Most of the available heavy metal concentrations in all soil leachate fractions were below the method detection limits. Mean concentrations of Ni, Cd, and Pb in wheat crops were far below the concentrations considered phytotoxic to wheat plants. More than 90% of the Ni, Cd, and Pb contained in the drainage water of the Al-Moheet drain were significantly present (p ≤ 0.05) and adsorbed by biochar in the top 20 cm of soil lysimeters, indicating the high biochar adsorptive capacity of heavy metals. Total counts of bacteria and fungi gradually and significantly increased over the soil incubation time despite irrigation with contaminated drainage water. Soil resistance index (SRI) values for microbial biomass were positive throughout the experiment and increased significantly as the application rate of corncob biochar increased. These results indicated the high feasibility of using corncob biochar at a rate of 3% to temporarily improve the health of sandy soil despite irrigation with drainage water.