Patrick Musinguzi

Prevalence of chronic obstructive pulmonary disease and associated risk factors in Uganda (FRESH AIR Uganda): a prospective cross-sectional observational study

BACKGROUND In sub-Saharan Africa, little is known about the damage to respiratory health caused by biomass smoke and tobacco smoke. We assessed the prevalence of chronic obstructive pulmonary disease (COPD) and related risk factors in a rural region of Uganda. METHODS We did this prospective observational cross-sectional study in rural Masindi, Uganda. We randomly selected people above the age of 30 years from 30 villages. Trained local health-care workers asked validated questionnaires and administered spirometry to participants. We defined COPD as FEV1:FVC less than the lower limit of normal. We calculated prevalence of COPD and tested its association with risk factors. FINDINGS Between April 13, and Aug 14, 2012, we invited 620 people to participate, of whom 588 provided acceptable spirometry and were analysed. Mean age was 45 years (SD 13·7); 297 (51%) were women. 546 (93%) were exposed to biomass smoke. The prevalence of COPD was 16·2% (15·4% in men, 16·8% in women). Prevalence was highest in people aged 30-39 years (17 [38%] of 45 men, 20 [40%] of 50 women). 20 (44%) of 45 men with COPD were current smokers (mean age 40 years, SD 7·5), 11 (24%) were former smokers (mean age 49 years, SD 11·0); four [8%] of 50 women were current smokers (mean age 52 years, SD 18·1), nine (18%) were former smokers (mean age 64 years, SD 16·2). Mean Clinical COPD Questionnaire score was 0·81 (SD 0·78), mean Medical Research Council dyspnoea score was 1·33 (SD 0·65); 28 (30%) of 95 patients had had one or more exacerbations past 12 months. COPD was associated with wheeze (odds ratio 2·17, 95% CI 1·09-4·34; p=0·028) and being a former smoker (1·96, 1·07-3·59; p=0·029). INTERPRETATION In this rural district of Uganda, COPD starts early in life. Major risk factors were biomass smoke for both sexes and tobacco smoke for men. In addition to high smoking prevalence in men, biomass smoke could be a major health threat to men and women in rural areas of Uganda. FUNDING International Primary Care Respiratory Group.

Nitrogen-neutrality: a step towards sustainability

We propose a novel indicator measuring one dimension of the sustainability of an entity in modern societies: Nitrogen-neutrality. N-neutrality strives to offset Nr releases an entity exerts on the environment from the release of reactive nitrogen (Nr) to the environment by reducing it and by offsetting the Nr releases elsewhere. N-neutrality also aims to increase awareness about the consequences of unintentional releases of nitrogen to the environment. N-neutrality is composed of two quantified elements: Nr released by an entity (e.g. on the basis of the N footprint) and Nr reduction from management and offset projects (N offset). It includes management strategies to reduce nitrogen losses before they occur (e.g., through energy conservation). Each of those elements faces specific challenges with regard to data availability and conceptual development. Impacts of Nr releases to the environment are manifold, and the impact profile of one unit of Nr release depends strongly on the compound released and the local susceptibility to Nr. As such, Nneutrality is more difficult to conceptualize and calculate than C-neutrality. We developed a workable conceptual framework for N-neutrality which was adapted for the 6th International Nitrogen Conference (N2013, Kampala, November 2013). Total N footprint of the surveyed meals at N2013 was 66kgN. A total of US

CRITICAL SOIL ORGANIC CARBON RANGE FOR OPTIMAL CROP RESPONSE TO MINERAL FERTILISER NITROGEN ON A FERRALSOL

3050 was collected from the participants and used to offset the conference’s N footprint by supporting the UN Millennium Village cluster Ruhiira in SouthWestern Uganda. The concept needs further development in particular to better incorporate the spatio-temporal variability of impacts and to standardize the methods to quantify the required N offset to neutralize the Nr releases impact. Criteria for compensation projects need to be sharply defined to allow the development of a market for N offset certificates. S Online supplementary data available from stacks.iop.org/ERL/9/115001/mmedia

Strategic nutrient management of field pea in southwestern Uganda

Soil Organic Carbon (SOC) is a major indicator of soil fertility in the tropics and underlies variability in crop response to mineral fertilizers. Critical SOC concentrations that interact positively with N fertilizer for optimal crop yield are less understood. A study was conducted on a Ferralsol in sub-humid Uganda to explore the critical range of SOC concentrations and associated fractions for optimal maize ( Zea mays L.) yield response to applied mineral N fertiliser. Maize grain yield response to N rates applied at 0, 25, 50 and 100 kg N ha −1 in 30 fields of low fertility (SOC 1.2%), medium fertility (SOC = 1.2–1.7%) and high fertility (SOC > 1.7%) was assessed. Soil was physically fractionated into sand-sized (63–2000 µm), silt-sized (2–63 µm) and clay-sized ( 1.2% SOC registered the highest agronomic efficiency (AE) and grain yield. Non-linear regression models predicted critical SOC for optimal yields to be 2.204% at the 50 kg N ha −1 rate. Overall, models predicted 1.9–2.2% SOC as the critical concentration range for high yields. The critical range of SOC concentrations corresponded to 3.5–5.0 g kg −1 sand-sized C and 9–11 g kg −1 for clay-sized C.

Maize Response to Fertilizer and Nitrogen Use Efficiency in Uganda

The highlands of south-western Uganda account for the bulk of field pea (Pisum sativum L.) produced and consumed in the country. The crop fetches a stable price, which is as high as that of beef, but it has remained outside the mainstream of the research process. Low soil fertility, unfortunately, is poised to eliminate the crop. Nitrogen, phosphorus and potassium have variously been reported as deficient on the bench terraces where crop production is primarily done. Strategic nutrient management requires that the most limiting nutrient is known in order to provide a foundation for designing effective and sustainable soil fertility management interventions. A study was conducted on upper and lower parts of the bench terraces on the highlands in south-western Uganda to identify the most required macro-nutrient(s) in field pea production. Treatments included: 0 and 25 kg N ha–1, 0 and 60 kg P ha–1, and 0 and 60 kg K ha–1, all applied factorially in a randomized complete block design. Parameters assessed included nodulation, nodule effectiveness for BNF and dry weight, shoot dry weight (SDW), and grain yield. Nutrient applications that resulted in the highest crop responses were considered as most required, and hence, most limiting to plant growth and yield. Phosphorus based nutrient combinations gave the highest increments in total and effective nodule numbers, as well as dry weight, irrespective of terrace position. On the other hand, N based combinations led to the highest shoot dry matter at flowering (39% higher over the control). The superiority of N was carried over up to final harvesting, with stover and grain yields edging out the other treatment regimes on either terrace positions.