Perceived stressors of climate vulnerability across scales in the Savannah zone of Ghana: a participatory approach

Smallholder farmers in sub-Saharan Africa are confronted with climatic and non-climatic stressors. Research attention has focused on climatic stressors, such as rainfall variability, with few empirical studies exploring non-climatic stressors and how these interact with climatic stressors at multiple scales to affect food security and livelihoods. This focus on climatic factors restricts understanding of the combinations of stressors that exacerbate the vulnerability of farming households and hampers the development of holistic climate change adaptation policies. This study addresses this particular research gap by adopting a multi-scale approach to understand how climatic and non-climatic stressors vary, and interact, across three spatial scales (household, community and district levels) to influence livelihood vulnerability of smallholder farming households in the Savannah zone of northern Ghana. This study across three case study villages utilises a series of participatory tools including semi-structured interviews, key informant interviews and focus group discussions. The incidence, importance, severity and overall risk indices for stressors are calculated at the household, community, and district levels. Results show that climatic and non-climatic stressors were perceived differently; yet, there were a number of common stressors including lack of money, high cost of farm inputs, erratic rainfall, cattle destruction of crops, limited access to markets and lack of agricultural equipment that crossed all scales. Results indicate that the gender of respondents influenced the perception and severity assessment of stressors on rural livelihoods at the community level. Findings suggest a mismatch between local and district level priorities that have implications for policy and development of agricultural and related livelihoods in rural communities. Ghana’s climate change adaptation policies need to take a more holistic approach that integrates both climatic and non-climatic factors to ensure policy coherence between national climate adaptation plans and District development plans

Growth and yield of rice as influenced by different levels of temperature, water and nitrogen under greenhouse condition

Increasing temperature and frequency of drought associated with climate variability and change and low soil fertility are factors that handicap sustained rice (Oryza sativa L) production in the tropics. In this study, the growth and yield of rice (Legon 1 rice variety) were investigated under three temperature regimes T1 = 33 °C, T2 = 34 °C, and T3 = 36 °C, two water regimes W1 = continuous flooding and W2 = intermittent irrigation, and two nitrogen application rates: (N1 = 0 kg N ha−1 and N2 = 90 kg N ha−1) at the Soil and Irrigation Research Centre, of the University of Ghana, Ghana. The experimental design was split-plot with temperature treatments as main plots and water and nitrogen applications as subplots with 4 replicates. The rice plants under high temperatures (T3 & T2) produced significantly lower biomass, nutrient uptake, and grain yield. Furthermore, the intermittent irrigation (W2) and nitrogen application (N2) significantly increased the percentage of yield components, grain yield, and nutrient uptake, The intermittent irrigation saved between 20 and 33% of irrigation water. The grain yield under the intermittent irrigation was 36, 24, and 15 g pot−1 for T1, T2, and T3, respectively, compared with 22, 14, and 8 g pot−1 for T1, T2, and T3 under the full continuous irrigation conditions. The uptake of nutrients was lower under the increased temperature with the rate of decline higher under nitrogen fertilization. The potential decline in grain quality due to reduced nutrient uptake poses a challenge for human nutrition under warmer climates

Interactive effects of soil compaction, biochar application, and soil water regime on the growth, yield, and water use efficiency of upland rice

ABSTRACT: The mechanization of tropical agriculture by conventional tillage has enhanced production and contributed to soil compaction, which has long term adverse effects on soil and crop productivity. Application of biochar is among the several remedial measures proposed to offset the compaction problem. Yet, it is unclear how biochar interacts with varying soil water that occurs under variable weather to mitigate the compaction problem. In this study, a screen house experiment was conducted to investigate the growth, yield, and water use efficiency (WUE) of upland rice (Nerica 14) grown under a range of biochar-amended compacted soils and soil water conditions. The experimental design was a completely randomized design (CRD) in a factorial arrangement with three bulk density (D) levels (D1= 1.30 Mg m−3, D2 = 1.50 Mg m−3, and D3 = 1.75 Mg m−3), two rates of rice husk biochar (RHB) application: (B) = 0 ton ha−1, and B10 = 10 ton ha−1), and three levels of seasonal irrigation (W1 = 391 mm, W2 = 419 mm, and W3 = 569 mm). Grain yield was influenced by biochar, bulk density and water regime. When averaged across irrigation levels, the B0 grain yields were 1336 kg ha−1, 947 kg ha−1 and 636 kg ha−1 for D1, D2 and D3, respectively. Biochar application reduced both the runoff, drainage, and improved the crop water use efficiency. In terms of WUE, the treatment combination of B10D1W1 and B10D3W3 recorded the highest (14.27 kg ha−1 mm−1), and least (9.28 kg ha−1 mm−1) values, respectively. Though biochar application improved the WUE under all density levels, high irrigation (W2, W3) could not compensate for the adverse effect of increasing soil density. It is concluded that the adverse impact of tillage-induced soil compaction on upland rice yield can be effectively alleviated by biochar application under varied soil water conditions

Assessment of Greenhouse Gas Emissions from Different Land-Use Systems: A Case Study of CO2 in the Southern Zone of Ghana

The emission of greenhouse gases (GHGs) results in global warming and climate change. The extent to which developing countries contribute to GHG emissions is not well known. This study reports findings on the effects of different land-use systems on GHG emissions (CO2 in this case) from two locations in the southern zone of Ghana, West Africa. Site one (located at Kpong) contained a heavy clay soil while site two (located at Legon) contained a light-textured sandy soil. Land-use systems include cattle kraals, natural forests, cultivated maize fields, and rice paddy fields at site one, and natural forest, woodlots, and cultivated soya bean fields at site two. CO2 emissions were measured using the gas entrapment method (PVC chambers). Trapping solutions were changed every 12–48 h and measurement lasted 9 to 15 days depending on the site. We found that, for the same land-use, CO2 emissions were higher on the clay soil (Kpong) than the sandy soil (Legon). In the clay soil environment, the highest average CO2 emission was observed from the cattle kraal (256.7 mg·m−2·h−1), followed by the forest (146.0 mg·m−2·h−1) and rice paddy (140.6 mg·m−2·h−1) field. The lowest average emission was observed for maize cropped land (112.0 mg·m−2·h−1). In the sandy soil environment, the highest average CO2 emission was observed from soya cropped land (52.5 mg·m−2·h−1), followed by the forest (47.4 mg·m−2·h−1) and woodlot (33.7 mg·m−2·h−1). Several factors influenced CO2 emissions from the different land-use systems. These include the inherent properties of the soils such as texture, temperature, and moisture content, which influenced CO2 production through their effect on soil microbial activity and root respiration. Practices that reduce CO2 emissions are likely to promote carbon sequestration, which will consequently maintain or increase crop productivity and thereby improve global or regional food security

Accounting for Weather Variability in Farm Management Resource Allocation in Northern Ghana: An Integrated Modeling Approach

Smallholder farmers in Northern Ghana face challenges due to weather variability and market volatility, hindering their ability to invest in sustainable intensification options. Modeling can help understand the relationships between productivity, environmental, and economical aspects, but few models have explored the effects of weather variability on crop management and resource allocation. This study introduces an integrated modeling approach to optimize resource allocation for smallholder mixed crop and livestock farming systems in Northern Ghana. The model combines a process-based crop model, farm simulation model, and annual optimization model. Crop model simulations are driven by a large ensemble of weather time series for two scenarios: good and bad weather. The model accounts for the effects of climate risks on farm management decisions, which can help in supporting investments in sustainable intensification practices, thereby bringing smallholder farmers out of poverty traps. The model was simulated for three different farm types represented in the region. The results suggest that farmers could increase their income by allocating more than 80% of their land to cash crops such as rice, groundnut, and soybeans. The optimized cropping patterns have an over 50% probability of increasing farm income, particularly under bad weather scenarios, compared with current cropping systems