African Journal of Agriculture

African Journal of Agriculture | Vol. 13, No. 4, April 2026 | pp. 009–016

DOI: 10.46882/2026/AJA/000735

Article Type: Original Research Article

Title: Spatio-Temporal Mapping of Soil Salinization in the Nile Delta Using Sentinel-2 Multi-Spectral Imagery and Machine Learning

Names of Authors: Amgad E. El-Mahdy¹, Fatma H. Al-Sherif¹

Authors’ Affiliations: ¹Department of Soil and Water Sciences, Faculty of Agriculture, Alexandria University, Alexandria, Egypt

Abstract: Soil salinization presents a profound environmental threat to agricultural sustainability in the coastal zone of the Nile Delta. Conventional laboratory testing is highly accurate but logistically slow and resource-intensive for large-scale monitoring. This study explored the efficacy of combining high-resolution Sentinel-2 multi-spectral satellite imagery with three machine learning algorithms—Random Forest (RF), Support Vector Machines (SVM), and Gradient Boosting Machines (GBM)—to predict and map topsoil electrical conductivity (ECe). Soil samples (n = 180) were collected at a depth of 0–15 cm from smallholder farms across Kafr El-Sheikh Governorate during the dry season. Spectral reflectance values, vegetative indices, and salinity indices extracted from cloud-free images were utilized as modeling predictors. Laboratory soil analysis revealed a wide variation in ECe, ranging from 1.25 to 18.64 dS/m. Among the models evaluated, the RF model achieved the highest predictive accuracy, yielding a coefficient of determination (R²) of 0.84, a Root Mean Square Error (RMSE) of 1.12 dS/m, and a Ratio of Performance to Deviation (RPD) of 2.34. The salinity index (SI-1) and the Normalized Difference Vegetation Index (NDVI) were identified as the most influential variables in predicting spatial salinity variations. The generated high-resolution salinity map revealed that 34.2% of the surveyed agricultural zone is severely affected by salinity, driven by sea-level rise and brackish water irrigation. This remote sensing framework enables rapid, cost-effective soil monitoring for targeted regional remediation.

Keywords: Remote sensing, Support vector machines, Random forest, Soil degradation, Nile delta, Electrical conductivity

Manuscript Timeline: Received: January 14, 2026; Revised: February 20, 2026; Accepted: March 12, 2026; Published: April 08, 2026

Citation: El-Mahdy, A. E., & Al-Sherif, F. H. (2026). Spatio-Temporal Mapping of Soil Salinization in the Nile Delta Using Sentinel-2 Multi-Spectral Imagery and Machine Learning. African Journal of Agriculture, 13(4), 009–016. DOI: 10.46882/2026/AJA/000735

African Journal of Agriculture ISSN 2375-1134 Vol. 13 (3), pp. 001-008, March, 2026. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper
 
Agronomic and Nutritional Characterization of QPM Varieties through Participatory Approaches in the Congolese Savanna

K. Mbuya^1,2, K. K. Nkongolo⁴*, A. Kalonji-Mbuyi^1,3 and R. Kizungu^1,2
 
1University of Kinshasa, B.P 117 Kinshasa 11, RD–Congo.
²Institut National pour l’ Etude et la Recherche Agronomiques (INERA), B.P. 2037, Kinshasa 1, RD-, Congo.
³Nuclear Research Center, Kinshasa, RD-Congo.
⁴Department of Biological Sciences, Laurentian University, Sudbury, Ontario, Canada.

Accepted 20 October, 2025

Maize (Zea mays L.) is a major cereal crop for human nutrition in the Democratic Republic of Congo (DR- Congo). Prevailing normal maize is deficient in two essential amino acids, lysine and tryptophan. Participatory variety selection was applied to select diversified quality protein maize (QPM) varieties that possess farmers’ preferred plant and grain traits. The varieties were planted with and without chemical fertilization. Selection was based primarily on agronomic traits such as time to maturity, plant and ear aspect, disease and insect resistance, yield and yield components as well as flour quality. There were significant differences among QPM varieties for several agronomic traits. The use of participatory approach in agricultural research allowed selection of one QPM, (QPMSRSYNTH), and one normal improved maize (AK9331-DMR-ESR-Y) for their yield advantage over currently released normal maize varieties in more than one criterion. The adoption of these newly introduced varieties is expected to be high since they were selected based on farmer’s preference.

Key words: Quality protein maize, participatory varietal selection, DR-Congo.
 

African Journal of Agriculture ISSN 2375-1134 Vol. 13 (3), pp. 001-005, March, 2026. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Nuclear DNA Content and Ploidy Levels of 48 Bermudagrass Accessions for Cultivar Breeding

Wenjing Pang¹*, William T. Crow¹ and Kevin E. Kenworthy²

¹Entomology and Nematology Department, University of Florida, Gainesville, FL 32611-0620, United States.
²Agronomy Department, University of Florida, Gainesville, FL 32611-0500, United States.

Accepted 9 December, 2025

Bermudagrass (Cynodon spp.) is widely used on golf courses and sport fields in Florida. Most cultivars used on golf courses are triploid bermudagrass (Cynodon dactylon [L.] Pers. var. dactylon × C. transvaalensis Burtt-Davy) resulting from hybridizations between tetraploid common bermudagrass and diploid African bermudagrass. In order to breed and develop bermudagrass cultivars with superior characteristics, it is essential to know the ploidy levels of available bermudagrass accessions and select fertile ones. The objective of this study was to determine the DNA content and ploidy level of bermudagrass germplasm accessions in the University of Florida germplasm collection to aid in future cultivar breeding. Flow cytometry was used to determine the nuclear DNA contents of 48 bermudagrass accessions, and one diploid (2%), 19 triploid (40%), 24 tetraploid (50%), one pentaploid (2%) and three hexaploid (6%) accessions were identified. The range of the nuclear DNA contents was 1.17, 1.38 to 1.61, 1.94 to 2.24, 2.47 and 2.64 to 2.75 pg/2C nucleus-1 for the respective ploidy levels. As such, tetraploid and hexaploid accessions could be utilized for future breeding efforts. The triploid accessions could be the results of mutations that have occurred in existing commercial bermudagrass cultivars or from natural hybrids between diploid C. transvaalensis and tetraploid C. dactylon.

Key words: Cynodon spp., flow cytometry, nuclear DNA content, ploidy level.
 

African Journal of Agriculture ISSN 2375-1134 Vol. 13 (2), pp. 001-006, February, 2026. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Gene Action and Combining Ability for Yield and Yield Components in Rajmash (Phaseolus vulgaris L.) Across Diverse Environments

Asif M. Iqbal, F. A. Nehvi, Shafiq A. Wani, H. Qadri, Z. A. Dar and Aijaz A. Lone*

Division of Plant Breeding and Genetics, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Shalimar, 191121, J and K, India.

Accepted 10 December, 2025

The experimental material comprised 45 F1’s generated by crossing ten diverse lines of common bean (Phaseolus vulgaris L.) in a half diallel fashion and their parents were evaluated in RBD in two replications at three locations during Kharif, 2008. The pooled analysis revealed that both gca and sca were influenced by environments, which suggested that studies are being conducted over the environments to get unbiased estimates. The sca x e interaction was greater than gca x e interaction for most of the traits. The compassion of relative magnitude of gca and sca variances indicated greater magnitude of sca variances for all the traits, indicating greater importance of non additive gene action for the inheritance of these traits. SKUA-R-607 and SKUA-R-608 showed high combining ability for seed yield and yield attributing traits. The most promising crosses, in order of merit for seed yield, were Shalimar rajmash 1 x SKUA-R-607, SKUA-R-608 x SKUA-R-106 and Shalimar rajmash -1 x SKUA- R-612.

Key words: Common bean, diallel, combining ability over environments, gene action.
 

African Journal of Agriculture ISSN 2375-1134 Vol. 13 (2), pp. 001-009, February, 2026. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Phenotypic and Agronomic Diversity of Sweet Potato (Ipomoea batatas [L.] Lam.) Germplasm in Tanzania

Fred Tairo*, Emmarold Mneney, and Alois Kullaya

Mikocheni Agricultural Research Institute, P. O. Box 6226, Dar-Es-Salaam, Tanzania.

Accepted 20 November, 2025

One hundred and thirty six sweet potato (Ipomoea batatas) landraces collected from three different agro-ecological zones of Tanzania [Lake Victoria basin (LZ), Eastern (EZ) and Southern Highlands Zones (SHZ)] were characterized morphologically and agronomically using International Potato Centre (CIP) descriptors in two seasons. The cluster analysis revealed existence of two major groups, 1 and 2 with low genetic variability of 0.52. Number of roots, weight of roots, fresh weight/plant and dry matter content differed significantly among and within agro-ecological zones. Landraces Lubisi from southern highlands zone had the highest number of roots (12 per plant) and Shinamugi from Eastern zone had highest dry matter content of 39.4%. Overall, landraces from Lake Zone recorded highest average root weight of 8,977.7 kg ha-1 followed by Southern highlands (7,561.2 kg ha-1) and Eastern zone (4,333.0 kg ha-1). Principal coordinate analysis (PCA) indicated variances accumulated by the first five components of the six major morphological characters was 52.5% and produced similar groups corresponding to those of cluster analysis. Our data indicate low genetic variation despite significant variations shown by agronomical traits. Many landraces recorded in different names from three different agro ecological zones showed close resemblance and grouped into two major groups suggesting presence of dupl-icates or mislabelling.

Keywords: Morphological traits, agronomical traits, diversity, germplasm characterization, Ipomoea batatas, sweet potato

African Journal of Agriculture ISSN 2375-1134 Vol. 13 (1), pp. 001-005, January, 2026. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Mitigative Effects of Calcium on Cadmium-Induced Oxidative Stress and Anti-Oxidative Enzyme Activity in Tomato Plants

Sbartai Hana¹, Rouabhi Rachid²*, Sbartai Ibtissem¹, Berrebbah Houria¹ and Djebar Mohammed-Réda¹

¹Cellular Toxicology Laboratory, Badji-Mokhtar Annaba University, Annaba, 23000, Algeria.
²Life and nature sciences Institute, Department of Biology, Tebessa University Center, 12000, Algeria.

Accepted 09 August, 2025

In the present study, the cadmium’s effect on anti-oxidative enzymes in tomato (Lycopersicon esculentum) plants was evaluated. Plants treated with increasingly CdCl2concentrations (0, 20, 40, 80, 100 and 200 µM respectively) were grown in a basic nutrient solution for 7 days. APX (Ascorbate Peroxidase) and GPX (Guaïgol Peroxidase) activities showed to increase below 100 µM concentration after treatment. In excessive concentration however, more than determined level, a significant decrease in the enzymes activities was determined. The increase in enzymatic activity can be associated with induction of oxidative stress by cadmium treatment. Excessive calcium displayed also low APX and GPX activities, which were virtually the same activity levels of control plants. However, it should be note that concentration more than 80 µm of Cd resulted in decreasing of APX and GPX activity. The enzymatic activity of GSH followed in the presence of Cd showed a significant increase by 80 µM of Cd then the activity showed decreasing. Calcium treatment resulted in impairing of GSH stimulation in the presence of Cd conditions. Eventually, Cd treatment resulted in decline in GST activity that was significantly increased in the presence of calcium, suggesting stimulation of antioxidant enzymatic activities. Therefore, accumulation of Cd can be associated with oxidative stress, which may be inhibited and reduced its adverse effects by calcium treatment in the cell culture.

Keywords: Cadmium, Calcium, APX, GPX, GSH, GST, Lycopersicon esculentum, enzymatic activity.