Spatial targeting of irrigation development and water resource management to mitigate vector-borne disease

Scaling irrigated agriculture is a global strategy to mitigate food insecurity concerns. While expanding irrigated agriculture is critical to meeting food production demands, it is important to consider how these land use and land cover changes (LULCC) may alter the water resources of landscapes and impact the spatiotemporal epidemiology of disease. Here, a generalizable method is presented to inform irrigation development decision-making aimed at increasing crop production through irrigation while simultaneously mitigating malaria risk to surrounding communities. Changes to the spatiotemporal patterns of malaria vector (Anopheles gambiae s.s.) suitability, driven by irrigated agricultural expansion, are presented for Malawi\u27s rainy and dry seasons. The methods presented may be applied to other geographical areas where sufficient irrigation and malaria prevalence data are available. Results show that approximately 8.60% and 1.78% of Malawi is maximally suitable for An. gambiae s.s. breeding in the rainy and dry seasons, respectively. However, the proposed LULCC from irrigated agriculture increases the maximally suitable land area in both seasons: 15.16% (rainy) and 2.17% (dry). Proposed irrigation development sites are analyzed and ranked according to their likelihood of increasing malaria risk for those closest to the schemes. Results illustrate how geospatial information on the anticipated change to the malaria landscape driven by increasing irrigated agricultural extent can assist in altering development plans, amending policies, or reassessing water resource management strategies to mitigate expected changes in malaria risk

Solar powered technologies for the smallholder dairy industry in Malawi

The study assesses proposed solar-powered dairy production technologies for smallholder dairy production systems in Malawi; evaluates the quantity and quality of milk produced; assesses socio-economic and gender impacts of the technologies, and promotes the uptake of the technologies. The introduction of a solar-powered water pump greatly reduced the amount of time spent fetching water for the dairy farm; solar milking machines (SMM) had the lowest milking time per cow. There were no significant differences between average milk yields per cow from machine milking and hand milking. The use of solar-powered groundwater pumps ensures a steady and easily accessible water supply

Optimising nutrient potential from compost and irrigation with wastewater to meet crop nutritional requirements

Globally agricultural production is facing serious challenges to provide adequate food supply to meet a growing population. However, the reduced capacity of soil to support and sustain agricultural production as a result of soil fertility decline is impacting negatively on agricultural growth. Increase in the price of inorganic fertilisers and limited availability of nutrients from organic amendments has reduced progress in improving soil fertility. This research therefore aims at contributing knowledge towards evaluating the maximisation/optimisation of nutrients in compost and secondary treated sewage effluent (STSE) amended soils to meet the nutritional requirements of crops for sustainable crop production and environmental protection. STSE was irrigated on soils (sandy loam and clay loam) amended with greenwaste compost in soil incubation, glasshouse/pot and lysimeter studies. Perennial ryegrass (Lolium perenne) was grown in the pots and lysimeter studies. The incubation experiment showed that for a clay loam, N mineralisation in treatments with STSE alone and combinations of compost and STSE was higher than the applied N. Increasing compost quantity in compost and STSE nutrient integration resulted in reduced net N mineralisation in the clay loam soil. In the sandy loam, increasing compost contribution in compost and STSE nutrient integration resulted in an increase in net N mineralisation. Cation exchange capacity, microbial diversity, quality of available carbon and drying and rewetting cycles influenced the net nitrogen mineralisation dynamics in both soil types. Increasing the contribution of STSE while reducing compost quantity resulted in increased nitrogen use efficiency and ryegrass dry matter yield. The environmental threat to ground and surface water pollution through NO3 --N leaching may be enhanced by the inclusion of STSE in integrated compost and STSE nutrient supply to plants. Similarly, the threat to eutrophication due to phosphorous leaching is likely to be higher with integration of compost and STSE. Ryegrass dry matter yield reduced with increasing compost contribution while the concentration of N in ryegrass herbage for the combinations of compost and STSE was above the minimum requirement for N in herbage for productive grazing and dairy cattle in the pot experiment. Using compost and STSE of similar characteristics, the ideal approach to maximise nutrient potential from compost through irrigation with STSE is when 25% compost is integrated with 75% STSE with respect to nitrogen supply.Commonwealth Scholarship Comissio

Barriers to commercialise produce for smallholder farmers in Malawi : an interpretive structural modelling approach

Smallholder farmers are among the most vulnerable communities in Sub-Saharan Africa, relying on agriculture for subsistence and employment. The transition from subsistence towards commercial agriculture is a focus area to improve the living conditions of farmers in several African countries, including Malawi. However, a number of barriers still prevents the commercialisation of produce by smallholder farmers. This work aims to identify the key barriers faced by Malawian smallholder farmers to commercialise their produce and to identify their root causes in order to prioritise areas of improvement to facilitate market participation for smallholder farmers. Using Interpretive Structural Modelling (ISM), the opinions of experts in the field were captured to establish causal and hierarchical relationships among the thirteen identified barriers, which holistically address on-farm and off-farm elements across multiple disciplines, such as agriculture, entrepreneurship, supply chain management, micro- and macro-economy. A causal mapping method is applied for the first time in the context of smallholder farming. This work is novel in identifying in a structured manner and comprehensively analysing barriers to commercialisation of produce for smallholder farmers in the context of Sub-Saharan Africa, offering a causal hierarchical mapping of the relationships between barriers in Malawi. The findings show that 'Poor farmers' group organisation' and 'Lack of market knowledge and understanding' are the most significant barriers, having the highest driving power and aggravating the other barriers. The findings of this work can have a notable contribution to practice. Policy makers and other related actors can have more clarity on the key barriers that affect all others as well as on their impact pathway, thus being able to prioritise their efforts to effectively address them

Water Use Efficiency Differences in Maize Varieties under Every Furrow and Alternate Furrow Irrigation

Water-use efficiency (WUE) differences of selected maize varieties under alternate and every furrow irrigation were investigated in a split-plot design trials with three replicates. Alternate furrow (AFI) and Every furrow irrigation (EFI) were main treatments and twenty maize varieties were sub-treatments. Plots were 64 m2 with one maize seed per station spaced at 0.25m apart. Crop water use results indicated that EFI consumed more water than the AFI. The AFI reduced crop water consumption by 38 - 45% compared to EFI. Differences were also prominent in maize varieties‟ response to AFI. Late maturing maize varieties proved to have minor yield reduction with AFI compared to early and medium maturing maize varieties. WUE (kg m-3 ) differed with irrigation water application strategy (P<0.001). AFI had high WUE. A combination of AFI with selection of water efficient maize varieties was a good strategy for improving WUE. The AFI is a promising furrow irrigation water management strategy for water saving. According to farmers experience at five irrigation schemes and on station research, it was concluded that AFI is one of the climate smart irrigation technique that farmer can easily adopt and apply as it saves labour, time water whilst reducing conflict for water among irrigators. It was recommended that AFI be applied fully on early and medium maturing maize varieties within an irrigation interval of 7 days. For late maturing maize varieties, AFI technique should be applied from initial stage to mid - stage (up 55 days from planting) then apply EFI at tasselling and silking stages to reduce water stress at this critical stage

Compost-Sewage Effluent Integration for Ryegrass Production

<div><p>This study evaluated effects of integrated application of compost and secondary treated sewage effluent (STSE) on net N mineralization (NM_net) and ryegrass production. Soil incubation and pot (glasshouse) trials were carried out on two soil types, sandy loam and clay loam. NM_net was significantly higher (p < 0.05) in clay loam than in sandy loam soil. Increasing contribution of compost in integrated compost and STSE resulted in N immobilization. Experimental data on ryegrass dry matter (DM) obtained in pot trial was consistent with NM_net trend observed in soil incubation. In pot trial, ryegrass DM yield and N use efficiency reduced with increasing contribution of N from compost. For every unit addition of compost (25%), DM yield of ryegrass declined by 573 and 462 kg DM⁻¹ in sandy loam and clay loam, respectively.</p></div