Nana Ewusi-Mensah

• PhD
• Professor (Associate) at Kwame Nkrumah University of Science and Technology

In several countries, invasive aquatic plants (IAP) have plagued most river systems, limiting their utilization. However, there is limited information on the conversion of this significant feedstock to biochar with agricultural value. Consequently, a field experiment was conducted to evaluate the influence of biochar from IAP (Arthropteris oriental...

Promoting investment in biomass composting is necessary to halt finite resource depletion and transition consumption and production processes into sustainable circular bioeconomy paths. This notwithstanding, there is a lack of demonstrable evidence of the economic viability of such investment, which often disincentivises the adoption of composting...

Food security issues continue to be a challenge in most parts of the globe, especially in sub-Saharan Africa (SSA). Several research attempts on addressing this issue have mainly been on nutrient replenishment using combined nutrient application of organic amendments and mineral fertilizer inputs. However, there is limited information available on...

This study evaluates the quality of compost produced from household biowaste (CBIO), aquatic invasive plants (CAIP) and a mixture of the invasive plants and biowaste (CBAIP) and the effect of their application on maize yield in comparison with mineral fertilizer (NPK). The composts were produced using Aerobin 400 Composter with aquatic invasive pla...

This study evaluates the quality and performance of compost produced from household biowaste (CBIO), aquatic invasive plants (CAIP) and a mixture of the invasive plants and biowaste (CBAIP) in comparison with mineral fertilizer (NPK) application. The composts were produced using Aerobin 400 Composter with aquatic invasive plant collected from the O...

A 70-day laboratory incubation study was conducted to unravel the mechanism(s) underlying synergistic interactions between organic and inorganic nutrient inputs to the soil. Soil from a maize farmer's field at Kpongu in the Upper West Region of Ghana was amended with a factorial combination of 0, 50% and 100% levels of the recommended rates (RR) of...

The poor quality of cow dung in Ghana resulting from the opportunistic feeding mode of cattle impedes its adoption due to high quantities needed for application. This calls for nutrient optimization of cattle manure with inexpensive locally available sources of organic inputs that could enhance its quality. Though large volumes of crop residues and...

Nitrogen is the most limiting major nutrient required by all living plants. Nitrogen fertilizer is costly and too much application of nitrogen causes detrimental effects to our ecosystem. Alternatively, the use of commercial microbial inoculants will be an alternative to chemical fertilizer for the small holder farmers in northern Nigeria. Groundnu...

For sustainable agriculture nitrogen must be adequately supplied because it is the most limiting major nutrient required by all living plants. This experiment was conducted at the two ecological zones, Sudan savannah in Kano State and Guinea savannah in Bauchi state of Nigeria during the 2016 cropping season. The design of the experiment was Random...

Mechanisms underlying interactive effects of nutrient inputs on crop yields are poorly understood especially throughout sub-Saharan Africa. This research thus sought to evaluate the possible mechanisms causing the interaction effects from compost and mineral fertilizer and quantify the relative contribution(s) of the mechanisms to added benefits in...

This paper provides a compendium of the utilisation potential of aquatic invasive plants found in the Owabi Dam in the Ashanti Region of Ghana. In total, seven aquatic invasive plants were identified in the Owabi Dam, which included Ceratophyllum demersum, Nymphaea odorata, Polygonum lanigerum, Arthropteris orientalis, Typha domingensis, Pistia str...

Greenhouse and multi-location experiments were conducted for two consecutive years to investigate the effects of rhizobium on nodulation, biomass production and partitioning of faba bean. Split-plot in randomized complete block design was used for field experiments. Treatments consisted of six rhizobium strains and three faba bean varieties. Peat c...

Cattle manure (CM) is noted for its poor nutrient quality especially in Ghana where most cattle are fed on a free range. There is therefore a need to improve its quality since it is a vital nutrient resource for smallholder farmers. An experiment was thus carried out by composting cocoa pod husk (CPH), palm kernel cake (PKC) and rock phosphate...

Low inherent nitrogen (N), phosphorus (P), and potassium (K) contents of smallholder farms limit maize grain yield. Maize grain yield response to N, P, and K mineral fertilizer application and economically optimal rates for nitrogen (EORN), phosphorus(EORP ), and potassium (EORK) were evaluated on a Ferric Acrisol within the semi-deciduous forest z...

Inherently low concentrations of soil nutrients and erratic rainfall pattern in sub-Sahara Africa limit soybean response to rhizobia inoculant and P-fertilizer. The study was conducted to: (i) improve soybean response to rhizobia inoculation and P-fertilizer through the addition of organic manure; (ii) enhance rain water use efficiency and (iii) de...

This study reports the effectiveness of some selected rhizobium strains in enhancing nitrogen fixation and nutrient uptake in Vicia faba L. Multi-location field experiments were conducted for two years (2016 and 2017) using a split-plot in randomized complete block design. Treatments comprised six rhizobium strains as the main plot factor and three...

The main objective of this study was to improve the growth of oil palm seedlings by using microbe plus to enhance phosphorous availability from rock phosphate under oil palm nursery was evaluated at Oil Palm Research Institute of Ghana, Kade-Kumasi. The study consisted of 16 treatments replicated 3 times in a 4 × 4 factorial experiment arranged in...

Research exploiting the effect of phosphorus-biochar interactions on biological nitrogen fixation (BNF) and nutrient uptake in legumes is very scarce. In this study, we examined the short-term effect of rice husk biochar and phosphorus application on nutrient uptake, nodulation and nitrogen fixation of cowpea in both pot and field experiments in th...

Low concentrations of P and organic manure in savanna soils limit cowpea response to rhizobia. The study was conducted to determine combined effect of P and organic manure on cowpea response to rhizobia in a factorial experiment arranged in randomized complete block design with three replications on smallholder farmers’ fields in northern Ghana in...

We assessed the influence of Azotobacter inoculated commercial compost on eggplant productivity and soil nutrient status in the semi-deciduous forest zone of Ghana. In randomized complete block design, eight treatments (Control, 2.5 t ha −1 compost, 5 t ha −1 compost, 100% recommended NPK fertilizer at 50 kg N, 30 kg ha −1 P 2 O 5 and 30 kg ha −1 K...

A two-year field experiment was conducted in Niger to explore the effects of integrated use of millet glume-derived compost (MGD-Compost) and NP fertilizer on soil microbial biomass carbon (Cmic), nitrogen (Nmic) and millet yields. Three compost rates (3000 kg ha⁻¹, 1500 kg ha⁻¹ and 0 kg ha⁻¹) and three NP fertilizer rates (100%, 50% and 0% of reco...

Soybean yields on smallholder farms in sub-Sahara Africa (SSA) are far below the potential yield thus creating a huge yield gap. Interventions are thus needed to bridge this yield gap and ascertain the factors influencing the yield variation. This study evaluated the on farm response of soybean to rhizobia inoculation and or mineral P fertilizer in...

Reliable information on the persistence of rhizobium in soil in the absence of host between growing periods is important in deciding whether inoculation on the same plot in subsequent seasons is necessary. This study determined the survival of introduced rhizobium strains and predominant factors that influence the declining rates of their populatio...

Savannas are widespread in sub-Saharan Africa (SSA) and play a major role in the global carbon balance. Extensive quantification of savanna carbon stocks in SSA will therefore contribute to better accounting of the global carbon budget in the era of climate change. In this study, we investigated the spatial distribution of carbon stocks of differen...

Low phosphorus availability in cultivated soils limits sustainable crop production in sub‐Saharan Africa. This study aimed at evaluating the effect of long‐term application of different types of organic amendments on soil P forms, P use efficiency and sorghum yields. A long term experiment established in 1980 at Saria in Burkina Faso, comparing the...

Increasing soil phosphorus and organic matter content for crop production while reducing the cost of production are required to facilitate the achievement of green revolution in Africa. Field and pot experiments were laid out during 2012 and 2013 to assess the effects of combined application of Kodjari phosphate rock (PR) and water soluble phosphor...

A field experiment was conducted at Kpongu in the Upper West region of Ghana to determine the added benefits in grain yield of maize derived from the concurrent use of manure and mineral fertilizer, and their cost effectiveness. Factorial combinations of cattle manure and mineral fertilizer each at 0, 50 and 100% of their recommended rates were eva...

This study evaluated the symbiotic effectiveness and economic evaluation of Rhizobium inoculants with the objective of recommending the most effective inoculant strain for soybean and cowpea production in Northern Ghana. Field experiments were established in three locations using randomized complete block design with five blocks. A total of four tr...

In Niger, farmers rely largely on organic resources such as manure and compost to address soil fertility problems and improve crop production. Ironically, they do not improve the fertilizer value of these organic resources or take into account their decomposition and nutrient release patterns before the application. This study aimed to assess the d...

Compatible rhizobia populations are seldom available in soils where soybean has not been grown before. Inoculating soybean seeds with superior rhizobia strains is necessary for nodulation and nitrogen fixation. Ironically, many commercial agricultural products (biological and chemical) claim increases in crop productivity but their efficacy cannot...

Compatible rhizobia populations are seldom available in soils where soybean has not been grown before. Inoculating soybean seeds with superior rhizobia strains is necessary for nodulation and nitrogen fixation. Ironically, many commercial agricultural products (biological and chemical) claim increases in crop productivity but their efficacy cannot...

The use of cow dung as a source of plant nutrients is widespread among many smallholder farmers in Ghana. The benefits of cow dung application in crop production depend on the amount, quality, nutrient-release patterns, and uptake by crops. Samples of cow dung from three main systems of manure management (free range, semi-intensive, and intensive)...

A study was conducted for three consecutive cropping seasons at the Central Agricultural Station, Kwadaso, Kumasi in the semi - deciduous forest zone of Ghana to investigate the seasonal variations of soil microbial biomass carbon, nitrogen and phosphorus under different nutrient management and cropping systems. The field experiment was a split - p...

This paper reports the short‐ term effects of organic and inorganic fertilizer applications on the culturable resident bacterial and fungal properties of a Ferric Acrisol in the semi‐deciduous forest zone of Ghana after three con‐ tinuous cropping seasons. The treatments were two compost types (i.e. 1:1 compost comprising 1 part made up of Chromola...

A field experiment to evaluate Soil Organic Carbon (SOC) and maize grain yield under different soil amendments and cropping systems was conducted in 2006 and 2007 at the Soil Research Institute, Kwadaso, Kumasi. The experiment was a split plot with three replications. The main plot factor (cropping systems) consisted of continuous maize, maize/soyb...

A survey was conducted in the Upper East region of Ghana to seek information on the fertility status of the soils, manure production, its management options and nutrient concentration that could be associated with quality. Analysis of soils from farmers’ fields showed that the soils are coarse textured, with low exchange capacity and organic matter...

A study was conducted through composting to evaluate the potential of Chromolaena odorata , Stylosanthes guianensis and maize stover mixture as sources of nutrients, for improving the fertilizer quality of cattle manure. Composting was done in a ratio of 1:1 and 2:1 plant materials mixture: manure. Mass loss and nutrient release from the composts w...

A field experiment was carried out to determine the nitrogen fixation ability of some soybean experimental lines and to determine the amount of residual nitrogen that could be made available to a succeeding arable crop. The study was undertaken at the Crops Research Institute, Fumesua, Kumasi. The experiment was laid out in a randomized complete bl...