Department of Crop and Soil Science Education

Assessment of heavy metals in selected dumpsite soils and plants in Kumasi and Asante Mampong, Ghana

Fri, 01 Jan 2021 00:00:00 GMT

Assessment of heavy metals in selected dumpsite soils and plants in Kumasi and Asante Mampong, Ghana Kyere, K. This study investigated dumpsite farmers’ soil physicochemical knowledge, heavy metals and their pollution levels in selected dumpsites and background soils and plants in Kumasi and Asante Mampong, Ghana (latitude 5o 50‘ 7.46’’ N, longitude 0o 15‘ 2.25’’ W). Chi - square (ꭓ2) test showed that dumpsites farmers’ soil knowledge had no association (p = 0.21) with farmers’ educational level but showed a significant (p = 0.02) association with farmers awareness that dumpsites soil contain toxic elements; and (p = 0.03) farmers awareness that plants on dumpsites absorb toxic elements. Metals level were determined in soils at 0 - 15 cm and 15 - 30 cm depths with edible parts of plantain and cocoyam; 0 - 30 cm depth of sampled soils in pots with lettuce under field conditions using an XL3t GOLD XRF mass spectrometer. Physicochemical properties of dumpsite soils were higher than that of background soils. Cr, Fe, Ni, Cu, Zn, As, Cd, Hg and Pb were higher by 15 – 25 %. Soil Cu, Zn and Hg at 0 - 15 cm and 15 - 30 cm; soil Ni, Zn and Hg in pots from Magazine dumpsite were all above WHO (2015) limits in soils. Cr, Fe and Hg in plantain leaves and fruits from Magazine dumpsite; Hg in cocoyam leaves from Kyeremfaso dumpsite, and Hg in cocoyam corms from Magazine dumpsite; Cr, Fe, Ni and Cd in lettuce shoots and roots in pots in Magazine dumpsite were above allowable levels by FAO/WHO (2011). Cr and Cd; Fe and Zn; Ni and Cu; Cu, Zn and As; Zn and As; As and Pb; Hg and Pb association showed they have similar contamination sources. Cr and Fe; Cu, Cr and Zn showed antagonistic and synergistic type of behavior. Soil pH, SOM, CEC, Clay and soil available P influenced Cr, Fe, Ni, Cu, Zn, As and Cd. Pollution indices (Igeo, EF, RTEF, TR and TF) indicated very high contamination for Fe, Cu, Zn and Hg in the order of KYE < AYE < SUA. Education on dumpsites farming must be intensified and excavate dumpsites to landfill sites. A thesis in the Department of Crop and Soil Sciences Education, Faculty of Agriculture Education, submitted to the school of graduate studies in partial fulfillment of the requirements for the award of the Degree of Doctor of Philosophy (Soil Science) in the University of Education, Winneba JULY, 2021

Temporal variability of tree litter fall, soil carbon stocks and hydrology of soils under different agricultural land uses

Sat, 01 Jan 2022 00:00:00 GMT

Temporal variability of tree litter fall, soil carbon stocks and hydrology of soils under different agricultural land uses Osei, B. Y. The research was conducted at the crop plantations of Akenten Appiah Minkah University of Skill training and Entreprenuarial Development (AMUSTED – Mampong in the forest-savannah transition agro-ecological zone of Ghana. The objective of the research was to assess the seasonal variations in litter fall, soil carbon accumulation and hydro-physical properties of soils under different agricultural land use. The experiment was a 5 × 6 factorial, laid in a randomized complete block design, with 5 different land uses and 6 distinct seasons. The land uses were forest stand, cocoa plantation, coffee plantation, cashew plantation and mango plantation while the seasons were dry season 2016, major rainy 2016, minor rainy 2016, dry season 2017, major rainy 2017 and minor rainy 2017. A field test was conducted to measure soil bulk density, volumetric moisture content, total porosity, air-filled porosity, degree of saturation and aggregate stability of soils under the different land uses. Cumulative infiltration, infiltration rate, sorptivity, steady state infiltrability and saturated hydraulic conductivity were also evaluated. For carbon accumulation, quantity of litter fall, soc, soil carbon stocks and soil carbon sequestration were measured. A laboratory analysis was carried out to measure total nitrogen, phosphorus, pH, exchangeable bases like calcium, magnesium, potassium. Microbial biomass (Cmic, Nmic and Pmic), microbial quotient (qCmic, qNmic and qPmic) and microbial biomass ratios (Cmic/Nmic, Cmic/Pmic and Nmic/Pmic) were all measured. The bulk densities of soils under the different land uses were significantly different (p<0.05) from each other, in the order mango > cashew > coffee > cocoa > forest. Both the soil gravimetric and volumetric moisture content differed significantly among land uses, with cashew and coffee recording the highest and lowest values in both instances, respectively. Significant (p<0.05) seasonal variations in soil moisture were observed in the order MNRS2017 > MNRS2016 > MRS2017 > MRS2016 > University of Education,Winneba http://ir.uew.edu.gh xv DS2017 > DS2016. The study showed, significant difference in total porosity, airfilled porosity and degree of saturation of the different land uses and seasonal variations, with aeration decreasing with increased rainfall amount. Aggregate stability was significantly different among the different land uses and season. Aggregate stability gradually improved over seasons by 1.5 % to 11.1 % from season DS2016 to MNRS2017. Hydrological and hydraulic properties of soils under the different land uses were significantly different from each other. Seasonal cumulative infiltration amount and hydraulic conductivity of soils ranged from and 90.2 to 154.1 mm and 0.036 to 0.077 mm s-1, respectively. Litter fall significantly differed among the different land uses, forest stand (3.28 t/ha) and mango plantation (2.27 t/ha) recorded the highest and lowest. Significant seasonal variations of litter fall were recorded, with DS2017 (4.06 t/ha) and MRS2016 (1.80 t/ha) recording the highest and lowest, respectively. Soil carbon stocks and soil carbon sequestration was highest (48.04 Mg C/ha and 179.2 CO2 Mg/ha) and lowest (45.7 Mg C/ha and 167.7 CO2 Mg/ha) in mango plantation and forest stand, respectively. Total nitrogen, available phosphorus, potassium, magnesium, calcium and pH were significantly different among the different land uses. Soil microbial biomass (Cmic, Nmic and Pmic) which ranged from 151.3 to 323.8 mg/kg, 22.28 to 47.32 mg/kg and 7.89 to 25.5 mg/kg, respectively differed significantly among the different land uses and seasons. Microbial quotients (qCmic, qNmc and qPmic) decreased in the dry seasons (DS2016 and DS2017), while it was highest in the minor rainy reasons (MNRS2016 and MNRS2017). It is recommended that, mango, cashew, cocoa and coffee could be used to store and sequester as much carbon as the forest when they are properly managed. Coffee > cocoa > cashew > mango improved soil hydrological and hydraulic properties in this order of efficiency. A thesis in the Department of Crop and Soil Sciences Education, Faculty of Agriculture Education, submitted to the School of Graduate Studies in partial fulfilment of the requirements for the award of the degree of Doctor of Philosophy (Soil Science) in the University of Education, Winneba JUNE, 2022

Genotype × environment interaction and yield stability analysis of some cowpea varieties released in Ghana from 1990 to 2005

Wed, 01 Jan 2020 00:00:00 GMT

Genotype × environment interaction and yield stability analysis of some cowpea varieties released in Ghana from 1990 to 2005 Atakora, K The phenological development, growth, yield and yield stability performance of eight cowpea varieties released in Ghana between 1990 and 2015 were evaluated in field experiments carried out at Mampong-Ashanti (forest-savannah transition zone) and Fumesua (forest zone) over two cropping seasons in 2015 and 2016. The experiments were arranged in a randomized complete block design (RCBD) with three replicates. Asontem, Nhyira, Asetenapa, Hewale and Videza flowered and podded earlier (37-44 days and 49- 51 days, respectively) than Soronko, Tona and Asomdwe (46-48 days and 52-55 days, respectively). Hewale, Asomdwe, Asontem and Videza by virtue of their erect and semierect architecture had the highest plant height in both seasons, while Tona recorded the lowest. Crop growth rate among the varieties ranged from 1.1-1.7 g/m2/day for Asetenapa, Tona and Videzea to 2.3-3.3 g/m2/day for Asontem, Nhyira, Soronko, Hewale and Asondwe. Pod yield ranged from 980-2540 kg/ha, with Videza and Soronko producing the lowest pod yields, while Asontem had the highest pod yield across both locations and cropping seasons. Seed yield ranged from 603-2241 kg/ha, with Asetenapa yielding the lowest (603-1407 kg/ha). Asontem produced the highest number of pods per plant and number of seeds per pod and thus the highest seed yields (1240-2241 kg/ha) over the locations and seasons. Pod harvest index ranged from 0.58-0.90. The four yield stability analysis methods used showed that Asontem and Tona were the most stable varieties and were adapted to all the environments, while Soronko and Asetenapa were the least stable and were adapted to more favourable environments. A thesis in the Department of Crops and Soil Sciences Education, Faculty of Agricultural Education, submitted to the School of Graduate Studies in partial fulfillment of the requirements for the award of the degree of Doctor of Philosophy (Agronomy) in theUniversity of Education, Winneba FEBRUARY, 2020