Fertilizer use efficiency and economic viability in maize production in the Savannah and transitional zones of Ghana

Increasing fertilizer use is highly justified for sustainable agricultural intensification if yield response, fertilizer use efficiency (FUE), and economic viability of fertilizer application are high. Despite the increasing fertilizer application rates in Ghana, yields only marginally increased. Also, the recent fertilizer price hikes post COVID-19 revived concern for economic analysis of fertilizers. This study analyzed the FUE and economic viability of fertilizer use in maize production in Guinea/Sudan Savannah and Transitional/Deciduous zones of Ghana. Survey data from 2,673 farmers in the 2019, 2020, and 2021 production seasons were used. The average agronomic efficiency (AE), partial factor productivity (PFP), and value-cost ratio (VCR) of fertilizer use were 2.2 kg of grains per kilogram of fertilizer, 18.3 kg grains per kilogram of fertilizer, and 1.8 Ghana cedis of marginal yield per Ghana cedi spent on fertilizer, respectively. Fertilizer use was economically viable for only 28.1% of farmers with a VCR of 2 or higher, while 52.5% reached the break-even point with a VCR of at least 1. Various fertilizer formulations, including NPK plus sulfur, and adoption of integrated soil fertility management (ISFM) practices, particularly improved seeds, organic fertilizers, and minimum tillage, improved maize yield response to fertilizer and thus the FUE. These low efficiency and economic viability of fertilizer use are prevailing conditions in other sub-Saharan Africa (SSA) countries and these do not guarantee sustainable food security and improved livelihood of the farmers in the region. Ghana’s Ministry of Food and Agriculture (MoFA), together with relevant stakeholders, should provide guidance on ISFM and intensify farmer education through farmer associations to increase the adoption of ISFM. The local government should work with other relevant stakeholders to improve the market conditions within the agriculture sector, for instance, by linking farmers to city markets for favorable output prices

Stimulus of nitrogen fertilizers and soil characteristics on maize yield and nitrous oxide emission from Ferric Luvisol in the Guinea Savanna agro-ecological zone of Ghana

Farmers in Ghana rely on different forms of fertilizers to increase crop yields. The quantity of applied mineral N fertilizer is lost through nitrification and denitrification in the form of the powerful greenhouse gas nitrous oxide (N2O) has not been determined in the field until now. This study was conducted on a Ferric Luvisol in the Tolon District in Northern Ghana to determine the influence of nitrogen fertilizers, soil moisture and soil temperature on N2O emissions and grain yield. Three different nitrogenous fertilizers, i.e. ammonia sulfate (AS), urea (U) and NPK 60–40–40, were applied at either 60 or 120 kg N ha−1 yr−1 to maize, termed AS 60, AS 120, U 60, U 120 and NPK 60–40–40 thereafter. A control was left without N application. The results showed that N fertilizer type and quantities applied affected N2O emissions significantly. Plots of NPK 60–40–40, AS 60 and U 60 emitted 1.22, 1.45 and 1.79 kg N2ON ha−1, respectively, throughout the sampling period and were not considerably higher than N2O emissions from the control plots, which amounted to 0.32 kg N2ON ha−1. In contrast, the N2O emissions of U 120 and AS 120 were significantly higher than the controls, with values of 4.29 and 3.49 kg N2ON ha−1, respectively. When N2O flux was related to grain yield, 1.24 and 1.04 g N2O kg−1 grain was emitted from AS 120 and U 120, respectively. Plots treated with NPK 60–40–40, AS 60 and U 60 produced 0.39, 0.47 and 0.55 g N2O kg−1 grain, respectively, whereas plots without fertilization emitted 0.53 g N2O kg−1 grain. Average N-induced N2O emission factors ranged between 0.10% and 0.22%, with an overall emission factor of 0.15%

Growth, Nodulation, and Yield Responses of Groundnut (Arachis hypogaea L.) as Influenced by Combined Application of Rhizobium Inoculant and Phosphorus in the Guinea Savanna Zone of Ghana

Groundnut yields obtained by farmers in northern Ghana are generally low due to low soil fertility resulting from continuous cropping coupled with low use of external inputs. There is therefore the need to use systems’ internal resources such as biological nitrogen fixation efficiently to enhance crop production. This on-station experiment investigated nodulation and pod yield responses of three groundnut varieties, namely Obolo, Oboshie and Samnut 22 to inoculation with rhizobium inoculants of exotic strains, namely Bradyrhizobium yuanmingense (BR 3267) and USDA 3456 in combination with 0 kg P ha−1, 15 kg P ha−1 and 30 kg P ha−1. Combined application of 30 kg P ha−1 and BR 3267 increased the nodule numbers in Obolo, Oboshie and Samnut 22 by 144%, 188% and 56%, respectively compared to their uninoculated counterparts. Inoculation with BR 3267 produced the highest pod yield in all the three varieties with yields increasing from 13 to 40% over that of the uninoculated treatments, with BR 3267-inoculated Samnut 22 giving the highest yield of 2013 kg ha−1. P fertilizer and rhizobium inoculant also had a significant interactive influence on the pod yield of groundnut. Combined application of 30 kg P ha−1 and rhizobium inoculation increased the groundnut yield by 64 to 68%. The study observed a positive interaction between the rhizobium strains and P fertilizer

Economic Viability of Smallholder Agriculture in the Savannah and Transitional Zones of Ghana: Implications of Farm Output Commercialization and Farm Diversification

Smallholder agriculture remains the heart of Ghana’s food crop production and crucial to meet the zero-hunger target. Unfortunately, rural households continue to see no significant improvement in their livelihoods, as poverty and food insecurity remain high in these areas. This has raised concerns about the economic viability of smallholder agriculture in Ghana. We estimated propensity score matching on a sample of 581 farmers to determine the economic viability of the smallholder farmers and the impact of farm output commercialization and off-farm diversification on their food security and welfare status. Large-scale (>2 ha) maize production led to 8% more yield and 96% more income than small-scale (≤2 ha) production. At observed mean levels, large-scale farmers performed better in most of the livelihood outcomes. The impact of diversification and commercialization on livelihood outcomes was mixed, based on the scale of production. For small-scale farmers, diversification reduced per capita consumption expenditure, while commercialization improved food security, consumption expenditure, and income. For large-scale farmers, diversification improved yield and food security, while commercialization improved fertilizer application rate and income but reduced yield. Although small-scale farmers are not necessarily doomed, the heterogeneity of farmers’ production scale should be considered in the design of rural agricultural policies