DEPARTMENT OF SOIL SCIENCE AND LAND MANAGEMENT

A study was carried out to determine the status of some micronutrients in soil under
Citrus orchard at the University of Benin and to show the relationship between the
selected micronutrients and some soil’s properties. At each location, an area measuring 300 m by 200 m was marked out and the area divided into 3 equal parts. Each part made a replicate, soil sample were collected from 0-15 cm, 15 - 30 cm and 30 - 45 cm soil depths. A total of 18 soil samples were collected and analyzed using approved laboratory techniques Sand did not increase with increased soil depths while Silt and Clay increased significantly with increased soil depths. The pH wasmoderately acidic(5.56-5.70). Total nitrogen was generally low, Available phosphorus and organic was below critical level. Exchangeable bases were below critical level except Na and K which were above critical level. There were negative and significant correlation between the micronutrients and Sand, Clay, Silt, Organic carbon,Calcium, Sodium, Potassium, Total nitrogen and available phosphorus. E.C positive and significant correlation with copper but negative and significant correlated with Iron, Manganese and zinc. pH however negative and significant correlated with Copper, Iron, Manganese but positively and significant correlated with Zinc.

The study reviewed the effects of poultry manure (PM) on the growth and yield of selected fruit and leafy vegetables in Nigeria. With the increasing need for sustainable and eco-friendly farming practices, poultry manure has become an important organic nutrient source due to its high content of nitrogen, phosphorus, potassium, and essential micronutrients. It enhances soil fertility, improves structure and water-holding capacity, and promotes beneficial microbial activity. Findings from several experimental trials across different agro-ecological zones in Nigeria revealed that poultry manure significantly improved vegetative growth and yield parameters such as plant height, leaf area, number of fruits, and total yield. The optimal application rate generally ranged between 10–30 t/ha, depending on crop type and soil condition. Studies also indicated that integrating poultry manure with inorganic fertilizers such as NPK 15:15:15 produced superior results in nutrient availability and crop performance. In conclusion poultry manure is a sustainable, cost-effective, and environmentally friendly soil amendment capable of improving vegetable productivity anmaintaining long-term soil health in Nigeria.

The oil palm industry generates large quantities of solid waste, particularly Empty Fruit Bunches
(EFB), which are often discarded despite their potential value as organic soil material. This study examined the effects of EFB on bacterial communities in oil palm rhizosphere soils collected from the Nigerian Institute for Oil Palm Research (NIFOR) in Edo State, Nigeria. Laboratory analyses were conducted to determine how different EFB application rates influenced soil properties and bacterial population structures. The results showed that moderate EFB application at 50kg to 100kg improved key soil parameters such as pH, organic carbon, and nutrient content. Although bacterial counts slightly decreased with EFB addition, beneficial species such as Bacillus subtilis and Enterobacter aerogenes were more prominent, exhibiting plant growth- promoting traits like nitrogen fixation and phosphate solubilization. However, the presence of Escherichia coli and Staphylococcus aureus indicated potential biosafety concerns. In conclusion, EFB enhances soil fertility and supports beneficial microbes, when applied in moderate rates (50kg- 100kg)

This study investigates the contents of some heavy metals (Cadmium (Cd) and Chromium (Cr)) concentrations in the soils of a dumpsite located within Egor Local Government Area in Benin City. Soil samples were randomly obtained from different locations within the dumpsite while the control soils were obtained from the Faculty of Agriculture University of Benin. A total of 18 samples were collected, with nine from the dumpsite and nine from the
control site at three different depths (0-15cm, 15-30cm, and 30-45cm). The experiment was thereafter laid out in a Completely Randomized Design (CRD). Results from the investigations shows that the dumpsite soils exhibited higher organic matter content (47.73, 38.00 and 31.03 gkg -1) that ranged from the topsoil to the subsoil while the control had 13.79, 10.57 and 10.51 gkg -1 respectively. The dumpsite also recorded reduced (5.04 – 6.13) acidity, which resulted in increased nutrient (N, P, K, Ca and Mg) release so was the cadmium (Cd) concentrations significantly elevated in the dumpsite soils, ranging from 5.14 - 8.18 mgkg -1 , compared with the content in the control (0.31 - 0.66 mgkg -1 .). The Cd (19.93 – 36.78 mgkg -1) and Cr (5.14 – 8.18 mgkg -1) contents in the dumpsite were highly above the permissible limit defined by World Health Organization. These findings underscore the potential impact of waste deposition, emphasizing the need for proper waste management practices to mitigate heavy metal contamination from getting into the food chain and as such it is recommended that the dumpsite investigated should not be used in the production of food crops intended for human consumption.

Calcium carbide is a chemical compound with the chemical formula of CaC2. Itsindustrial use involved in the production of acetylene and calcium cyanamide. Inessencecalcium carbide poses a greater threat to soil fertility, leading to low productivityof cropsand livestock. The study was conducted at different mechanic workshops in Egor local government areaof Edo state. The study was done to access effects of calcium carbide on soil fertility. Theexperiment was a 3×3×3 factorial experiment that is three different workshops at threedifferent depth replicated three times. The total amount of hydrocarbon in location1shows there is decrease in soil fertility furthermore the available phosphorus decreasesinlocation 1 inferred that phosphorus is being held up by aluminumand hydrogenions. Same with the results for available phosphorus in location 2. Recommendations suchasmulching, physical methods such as scraping is needed to improve soil fertility

This study evaluated the effectiveness of poultry manure (PM) as a low-cost soil amendment for improving growth and yield of fluted pumpkin (Telfairia occidentalis) on nutrient-depleted soil. The study was carried out in 2025 at the Experimental Field of the Faculty of Agriculture, University of Benin, Benin City. This experiment was laid out on a Randomized complete block design (RCBD) with four different treatments and three replicates. The treatment rates were control(0), 5tonnes, 10tonnes and 15tonnes/ha. The treatments were four levels of poultry manure; control(0) 5tonnes, 10tonnes and 15tonnes/ha. The plant parameters measured were; vine length, number of leaves and stem girth. The growth parameters were recorded 4 WAP, 6 WAP and 8 weeks after planting, while soil properties (pH, organic carbon, total N, available P and exchangeable K) were taken before planting. The initial experiment showed the pH of the soil was moderately acidic (5.45), the textural class before the experiment was sand and low in total nitrogen ( 0.35g) indicating generally low fertility. The least value of Number of leaf was recorded in control plot ( 32.3 leaves) at 4 WAP which
was lower than the rest treatment levels at different weeks observed, while the highest value of number of leaves was recorded in soil treated with 15tonnes poultry manure ( 322 leaves) at 8 WAP and was significantly higher to other weeks observed in each treatment. The control plots recorded the lowest vine length value of 103.3cm at 4 WAP for fluted pumpkin. While the highest vine length was recorded at 15tonnes 388.7cm at 8 WAP. This means, application of poultry manure significantly (P>0.05) enhanced growth performance of fluted pumpkin on the degraded soil and application of 15 tonnes poultry manure had significant (P>0.05) increased the yield of Telfairia occidentalis. Therefore,15 tonnes poultry manure application significantly (P>0.05) increased the growth and marketable leaf yield ofTelfairia occidentalis.

The study was conducted to investigate the impact of oil palm empty fruit bunches (EFB) onthe fungal community structure and diversity within the rhizosphere of Elaeis guineensisL. at the Nigerian Institute for Oil Palm Research (NIFOR), Edo State. EFB, a lignocellulosicby product of palm oil processing, was applied at varying rates (0, 50, 100, and 150kg) toassess its effects on soil physicochemical properties and fungal dynamics. Standardlaboratory analyses were used to evaluate soil parameters, while fungal enumerationandidentification were conducted through morphological and microscopic characterization. Results revealed that moderate EFB application (100 kg) significantly (P ≥ 0.05) improvedsoil properties, while enhancing fungal abundance and diversity. Identified fungi specieswere Aspergillus niger, Trichoderma sp., Penicillium sp., Rhizopus arrhizus, andMucormucedo, with Trichoderma sp. exhibiting notable phosphate-solubilizing and nitrogen-fixingproperties. However, excessive EFB application (150 kg) led to nutrient immobilizationandreduced fungal proliferation. In conclusion, moderate EFB incorporation at 100kg optimizessoil health and promotes beneficial fungal communities, offering a sustainable approachforenhancing oil palm productivity in tropical soils.

Phosphorus (P) is a critical macronutrient essential for plant growth, it involved in energy transfer, cell division, and development of root systems. This study was conducted to examine different forms of inorganic phosphorus in soils planted to plantain. The study was conducted between April-October 2025, on twelve (12) soil samples collected from five (4) depths, three (3) replicates in soils planted to plantain within University of Benin, Edo States, Nigeria. Some soil properties were determined using standard laboratory procedures, Forms of inorganic P were determined by six step sequential fractionation using suitable chemical extractants, while the relationship between some soil properties and forms of inorganic P was
evaluated by simple linear correlation. Genstat (12 th edition) statistical package was employed for data analysis, Duncan multiple ranged test was used to separate means at 5%. Results revealed that various forms of inorganic P were distributed in the soils with the Al and Fe bound P forms occurring in the largest amount with grand mean values of 88.83 and 51.80 mg kg -1 respectively. The forms of P in the soils were influenced negatively and positively by some soils properties across the various soil depths, however at 0-30 cm soil depths Ca bound P correlated positively with Ca+Mg (r= 0.997*), saloid bound P showed significant positive and negative relationship with sand (r = -1.000 ***) and Organic carbon (r = 1.000***) respectively, the relation between other soil properties, with some forms of inorganic P were also obtained

Habanero pepper (Capsicum chinense Jacq.) is an important horticultural crop in Nigeria, but its yield potential is constrained by poor soil fertility and unsustainable tillage practices. This study was undertaken to evaluate the effects of tillage practices and nitrogen fertilizer application rates on performance of Habanero pepper under field conditions in Benin City, Edo State, Nigeria.
The field experiment was a 2 × 4 factorial arrangement fitted into a randomized complete block design with four nitrogen fertilizer rates (0, 40, 80, and 120 kg N/ha) and two tillage systems (minimum tillage and no-tillage) with three replications. Composite soil samples were collected and analyzed for physical and chemical properties before and after planting. Agronomic data collected includes plant height, number of leaves, number of branches, stem girth, and yield. Nutrient uptake, nutrient use efficiency (NUE), and nutrient balance sheets were used to assess fertilizer responsiveness.
Results showed that nitrogen application significantly affected soil pH, organic matter, and nutrient availability, with high N rates (120 kg/ha) resulting to acidification and organic matter decline. Minimum tillage enhanced nutrient uptake and plant growth compared to no-tillage. Optimal plant growth and yield were achieved under the interaction of minimum tillage and moderate nitrogen rates (40 and 80 with yield values of 4.42t/ha and 4.16t/ha respectively). NUE peaked at 40 kg N/ha and declined at higher rates, while nutrient balance sheets indicated surplus nitrogen with increased N inputs (120kg/ha). The study suggests that integrating 40–80 kg N/ha with minimum tillage optimizes Habanero pepper growth, yield, and soil quality and NUE, excessive N application should be avoided to promote healthy soil environment and ensure sustainable vegetable production systems in Nigeria.

This study was conducted in the Greenhouse of the Department of Soil Science and Land Management, Faculty of Agriculture, University of Benin, Benin City, to determine the heavy metal concentration of Celosia argentae raised on soils from dumpsites in Benin City, Edo State. Soil samples were collected from dumpsites from three different land uses around Ugbowo Campus of University of Benin City. The soils from the dumpsites were filled into plastic buckets and used to raise Celosia argentae. The experiment was laid out in a Completely Randomized Design (CRD) with three treatments and replicated three times. Soil and plant sample were collected and taken to the laboratory for analysis and standard
procedures were used to analyze the samples. Data obtained were subjected to analysis of variance (ANOVA) and Duncan’s New Multiple Range Test was used to separate the means at 5% level of significance. The parameters measured include: pH, Total organic carbon, Total nitrogen, Available phosphorus, Sand, Silt, Clay, Boron, Chlorine, Copper, Iron, Manganese, Molybdenum, Zinc, Lead, Chromium and Cadmium for the dumpsite soils, while the micro nutrients (Boron, Chlorine, Copper, Iron, Manganese, Molybdenum, Zinc) and heavy metals (Lead, Chromium and Cadmium) for the plant samples. The results show that the pH of the soils from the dumpsites were moderately acidic (5.66 – 5.92). The soils belong to the textural class sand