Spatially explicit information on soil variability is relevant for agronomic decisions; however, such information is limited in the northern Guinea savanna (NGS) agroecological zone of Nigeria. This study was conducted to delineate soil nutrient management zones (MZs), based on spatial variability of soils in the smallholder maize-based farming system within the NGS. Two hundred and eighty-nine soil samples were analyzed for some physical and chemical properties. Principal component analysis (PCA) was used to aggregate the soil properties into four principal components, which accounted for about 60 of the variation in the data, and spatial variability was assessed with a semivariogram. The ordinary kriging technique was used to predict soil properties at unsampled locations, while weighted overlay analysis was conducted to delineate nutrient management zones. Results showed that total nitrogen (0.06), available phosphorus (5.6mgkg⁻¹), organic carbon (0.66), and effective cation exchange capacity (5.6cmol₍₊₎ kg⁻¹) are below optimal requirement for maize production. Four MZs were identifiable in the region with the highest fertility (MZ3 and MZ4) associated with the northern area but covering a relatively small part (9.1). The differences observed in soil properties among the MZs suggest that each zone requires different agronomic management, especially in relation to fertilizer application.

This study evaluated the potentials of pollution due to urban agriculture to pose risk to food security in Kano, Nigeria. Two sites irrigated with industrial and domestic wastewaters at Challawa and Jakara, respectively, were sampled for soil, water, and lettuce (Lactuca sativa L.). The samples were analyzed for Pb, Cd, Cr, and Cu being metals which when present in food may pose human health hazard. The values were compared with samples from a control site not associated with wastewater at Watari. The sites were each segmented into up, mid, and downstream sectors. Results showed that the two sites and the control were contaminated with Cu (pollution indexes [PI] = 0.14, 0.16, and 0.14, respectively). Domestic wastewater site was slightly polluted (PI = 1.09) while industrial wastewater site and the control were contaminated (PI = 0.8 and 0.54, respectively) with Pb. The two sites were excessively polluted with Cd and slightly polluted with Cr. The control was contaminated with both (PI = 0.74 and 0.06 for Cd and Cr, respectively). Metal levels in the waters of the sites and the control were higher than the recommended threshold for irrigation water. There was significant positive correlation between Pb, Cr, and Cd in water and in soil; while Cu in soil and in water negatively correlated. There was high metal transfer from soil to plants at the domestic wastewater site (Metal transfer factor Pb = 1.602, Cr = 1.126, and Cu = 1.834). Plants' accumulated concentrations were also high at the domestic wastewater site (Pb = 26.21 mg/kg, Cd = 1.03 mg/kg, Cr = 28.63, and Cu = 2.66 mg/kg). The plants' metal concentrations at the domestic wastewater site exceeded the allowable limits in vegetables. The human ingestion risk was in the order of Jakara > Challawa > Watari.

This research sought to investigate how using organic amendments derived from readily accessible materials affects both tomato production and the electrochemical characteristics of soilless growing media. A greenhouse experiment using six (6) different locally accessible and underutilized composted organic materials [cocoa peat, rice husk, ground Doum palm (Hyphaene thebaica) fruit, Iroko (Milicia excelsa) saw dust, mahogany (Khaya senegelensis) saw dust, and Sapele saw dust (Entandophragma cylindricum)] was carried out. Standard procedures were used to determine the physical, chemical, and electrochemical characteristics of the modified materials.The results revealed that the highest water retaining capacity of the media varied from 51.11% to 85.56%. Iroko palm has the highest bulk density (0.94 g cm-3) while Doum palm has the highest particle density (0.81 g cm-3). The results of the study showed that the pH of the medium in KCl ranged from 6.32 to 7.81 and 7.36 to 8.37 for pH in water. The electrical potentials for the different media ranged from -52.01 to -93.38. The point zero charge of soils was shown to be positively correlated to the properties of the medium. The pH, electrical conductivity (ECe), and cation exchange capacity (CEC) of the media all increased when the media was modified. It is recommended that rice husks and cocopeat be used as growing given their superior performance compared to the other tested media in tomato production. However, because of the cost of producing cocopeat media, rice husk can serve as an alternative to cocopeat as a growing medium. Despite a slight delay in germination in the rice husk media, a high yield was attained at the end of production.

A survey was conducted during dry and rainy seasons of 2011 in order to determine the phytosociological attributes of acquatic weeds of Kano-Hadeja-Nguru wetlands. Random quadrat method was adopted for the phytosociological studies. The study areas consisted of communities from Kano, Jigawa and Yobe States. In each state, six communities were randomly selected. In each community20 quadrats of 4 m² size were laid down and hence sum of 120 quadrats were randomly thrown for each state. Within each quadrat area, weeds were identified, counted and weed cover scores were recorded. Weeds were cut at ground level, fresh and dry weights were determined. Typha grass was the most dominant species in the wetlands of Jigawa (21.195 and 22.5%) compared to either Kano (9.345 and 5.27%) or Yobe (12.73 and12.135%) states. Weed density, weed cover scores as well as fresh and dry weight of weed samples from Kano were observed to be higher than the other two states. Morphological characteristics of Typha spp found in Kano State were taller with more leaves than the other two states. The study suggested that there is strong need to start an Integrated Typha management in the study areas. Keywords: Phytosocioloy, aquatic weed, wetlands, Typha morphology

This research was conducted on the irrigated soils along the banks of the Jakara River within the metropolitan Kano and its suburb. Soil samples were collected between latitude 11o59’ and 12o 08’N and longitude 8o34’ and 8o 42’E at an altitude of 486.5m. The study investigated the effects of some heavy metals (Cd, Pb and Cu) on the fertility indices of the soil. Grid sampling was employed in which 100m2 of land was randomly selected in each of two sampling areas and was divided into ten equally sized grid cells of 10m2. Samples were analyzed for lead, cadmium and copper concentrations as well as fertility related parameters such as CEC and basic cations. Data obtained was subjected to correlation analysis using the Pearson moment correlation coefficient technique. The mean values of the heavy metals and the fertility indices are considered for the two sampling areas in bulk. Significantly positive correlation was found to exist between CEC, organic matter, nitrogen and phosphorus at P = 0.01. Significantly positive correlation was also found to exist between lead and potassium; lead and phosphorus; nitrogen and magnesium and copper and phosphorus. The quality of the soil for production is not immediately under threat especially with the very low mean values of the pollutants and the lack of significant effects they exert on many of the fertility indices determined.

This study examined the socio-economic impact of the parasitic weed Striga infestation and the effectiveness of local and conventional control measures in Nigeria’s Gombe, Kano, and Jigawa States. Cross-sectional data from 925 respondents in 2020 was analyzed using descriptive and inferential statistics. Most respondents were male (94.8%), married (85%), and engaged in crop production (64%). The average landholding per household was 2 hectares, primarily used for cereal and legume cultivation, such as maize, sorghum, cowpea, and millet. The majority practiced mixed cropping (88%). Soil texture, moisture retention, color, and grass species appearance were used to assess farmland fertility. Striga infestation’s negative effects included stunted growth (59%), yellowing of crops (57%), yield decline (51%), and soil fertility reduction (19%). Respondents considered continuous cropping (63%), low fertilization (89%), poor crop management (79%), low rainfall (45%), and high temperature (45%) as the main causes of Striga infestation. Farmers used various methods for control, including appropriate fertilizer application (75%) and weeding (68%). Indigenous methods like a mixture of salt and potash and Parkia fruit powder were also common. The effectiveness of indigenous and conventional methods showed no significant difference between Jigawa and Katsina. In conclusion, Striga infestation significantly threatens crop production, income, and food security. It can be managed through both conventional and indigenous methods. Efforts should focus on educating farmers about agronomic practices to mitigate Striga infestation and promote the adoption of Striga-resistant crop varieties, especially in Striga-prone areas.