Legume-maize rotation or relay? Options for ecological intensification of smallholder farms in the Guinea Savanna of northern Ghana

Article purchasedSoil nutrient constraints coupled with erratic rainfall have led to poor crop yields and occasionally to crop failure in sole cropping in the Guinea savanna of West Africa. We explored different maize-grain legume diversification and intensification options that can contribute to mitigating risks of crop failure, increase crop productivity under different soil fertility levels, while improving soil fertility due to biological N2-fixation by the legume. There were four relay patterns with cowpea sown first and maize sown at least 2 weeks after sowing (WAS) cowpea; two relay patterns with maize sown first and cowpea sown at least 3 WAS maize in different spatial arrangements. These were compared with groundnut-maize, soybean–maize, fallow-maize and continuous maize rotations in fields high, medium and poor in fertility at a site each in the southern (SGS) and northern (NGS) Guinea savanna of northern Ghana. Legumes grown in the poorly fertile fields relied more on N2-fixation for growth leading to generally larger net N inputs to the soil. Crop yields declined with decreasing soil fertility and were larger in the SGS than in the NGS due to more favourable rainfall and soil fertility. Spatial arrangements of relay intercrops did not have any significant impact on maize and legume grain yields. Sowing maize first followed by a cowpea relay resulted in 0.18–0.26 t ha−1 reduction in cowpea grain yield relative to cowpea sown from the onset. Relaying maize into cowpea led to a 0.29–0.64 t ha−1 reduction in maize grain yield relative to maize sown from the onset in the SGS. In the NGS, a decline of 0.66 and 0.82 t ha−1 in maize grain yield relative to maize sown from the onset was observed due to less rainfall received by the relay maize. Groundnut and soybean induced 0.38–1.01 t ha−1 more grain yield of a subsequent maize relative to continuous maize, and 1.17–1.71 t ha−1 more yield relative to relay maize across both sites. Accumulated crop yields over both years suggest that sowing maize first followed by cowpea relay is a promising ecological intensification option besides the more common legume–maize rotation in the Guinea savanna, as it was comparable with soybean–maize rotation and more productive than the other treatments

The Association between Adult Sport, Fitness, and Recreational Physical Activity and Number and Age of Children Present in the Household: A Secondary Analysis Using NHANES

Article describes how only one in three adults in the United States meets the weekly recommendation for physical activity. The purpose of this study was to examine the association between adult moderate and vigorous sport, fitness, and recreational physical activities and the number and age (0–5 and 6–17) of children in their household

Environmental impact of organic pineapple production in Ghana: a comparison of two farms using Life Cycle Assessment (LCA) approach

This LCA analysed and compared the environmental impact of producing 1 kg of organic pineapples on farm A to 1 kg on farm B. Environmental impact categories considered were Global Warming Potential (GWP); Acidification Potential (AP); Eutrophication Potential (EP) and Erosion Potential (ErP). Results indicate that farm B was more environmentally friendly than farm A with respect to all impact categories. The environmental impacts per kg product for farm A were between 12% (GWP) and 85% (EP) higher. It is suggested that farm A could improve its environmental performance by (i) replacing its organic fertiliser imported from the Netherlands by locally produced composts and (ii) increasing its yield per hectare. More than 50 percent of the impacts in the categories GWP, AP and EP were due to energy-related emissions. Thus, energy use should be considered when designing certification schemes or assessing the environmental soundness of agriculture production systems

N_2-fixation and N contribution by grain legumes under different soil fertility status and cropping systems in the Guinea savanna of northern Ghana

Continuous cereal-based cropping has led to a rapid decline in soil fertility in the Guinea savanna agro-ecological zone of northern Ghana with corresponding low crop yields. We evaluated the effects of cropping system and soil fertility status on grain yields and N2-fixation by grain legumes and net N contribution to soil fertility improvement in contrasting sites in this agro-ecological zone. Maize was intercropped with cowpea, soybean and groundnut within a row, with a maize stand alternated with two equally spaced cowpea or groundnut stands and in the maize-soybean system, four equally spaced soybean stands. These intercrops were compared with sole crops of maize, cowpea, soybean and groundnut in fertile and poorly fertile fields at sites in the southern (SGS) and the northern (NGS) Guinea savanna. The proportion of N derived from N2-fixation (%Ndfa) was comparable between intercrops and sole crops. However, the amount of N2-fixed was significantly larger in sole crops due to a greater biomass accumulation. Legumes in poorly fertile fields had significantly smaller shoot δ 15N enrichment (-2.8 to +0.7‰) and a larger %Ndfa (55-94%) than those in fertile fields (-0.8 to +2.2‰; 23-85%). The N2-fixed however was larger in fertile fields (16-145kgNha-1) than in poorly fertile fields (15-123kgNha-1) due to greater shoot dry matter and N yields. The legumes grown in the NGS obtained more of their N requirements from atmospheric N2-fixation (73-88%) than legumes grown in the SGS (41-69%). The partial soil N balance (inkgha-1) was comparable between intercrops (-14 to 21) and sole legumes (-8 to 23) but smaller than that of sole maize receiving N fertiliser (+7 to +34). With other N inputs (aerial deposition) and outputs (leaching and gaseous losses) unaccounted for, there is uncertainty surrounding the actual amount of soil N balances of the cropping systems, indicating that partial N balances are not reliable indicators of the sustainability of cropping systems. Nevertheless, the systems with legumes seem more attractive due to several non-N benefits. Our results suggest that soybean could be targeted in the SGS and cowpea in the NGS for greater productivity while groundnut is suited to both environments. Grain legumes grown in poorly fertile fields contributed more net N to the soil but growing legumes in fertile fields seems more lucrative due to greater grain and stover yields and non-N benefits

Sex-Specific Differences in the Association Between Race/Ethnicity and NAFLD Among US Population

Non-alcoholic fatty liver disease (NAFLD) is spreading worldwide, with a racial/ethnic disparity. We examined the gender role in the racial/ethnic difference in NAFLD in the US population. We analyzed data for 3,292 individuals ≥18 years old from NHANES 2017–2018, a representative sample of the non-institutionalized adult population in the US. Exclusions were subjects with elevated transferrin level, chronic hepatitis B or C, excessive alcohol use, or prescription medications that might cause hepatic steatosis. NAFLD was diagnosed by FibroScan® using controlled attenuation parameter (CAP) values: S0 290. Data were analyzed using Chi square and multinomial regression. The overall prevalence of NAFLD was 47.9% [S2 = 16.1%, and S3 = 31.8%]. The prevalence of S3 was highest among Mexican Americans (46%), lowest among Blacks (22.7%), 29.9% in other Hispanics and 32.1% in Whites (p \u3c 0.05). It was higher among Mexican American males (54.1%) compared to Mexican American females (37.7%) (p \u3c 0.05). In the adjusted model, Mexican Americans were two times more likely than Whites to have S2 and S3 (p \u3c 0.05). Only male Mexican Americans had higher odds of S2 and S3 relative to male White (p \u3c 0.05). Males had higher odds of S3 relative to non-menopausal females (p \u3c 0.05). There was no difference in the odds of S2 or S3 NAFLD among the menopausal females with or without hormone therapy relative to non-menopausal females (p \u3e 0.05). While Mexican Americans had the highest prevalence of severe NAFLD relative to the other racial/ethnic groups, only male Mexican Americans, but not females, had higher likelihood of both moderate and severe NAFLD relative to Whites. Interventions that specifically target Mexican American males are needed to increase awareness about NAFLD and its prevention

Reassessment of the Hispanic Disparity: Hepatic Steatosis Is More Prevalent in Mexican Americans Than Other Hispanics.

Hepatic steatosis (HS) is a growing problem in adults worldwide, with racial/ethnic disparity in the prevalence of the disease. The purpose of this study was to characterize the racial/ethnic prevalence of the stages (normal/mild [S0/S1], moderate [S2], and severe [S3]) of HS in Mexican Americans and other Hispanics compared to other racial/ethnic groups. We analyzed data for 5,492 individuals 12 years and older from the newly released National Health and Nutrition Examination Survey 2017-2018, which is a representative sample of the US adult population. HS was diagnosed by FibroScan using controlled attenuation parameter values: S0, <238; S1, 238-259; S2, 260-290; S3, >290. We analyzed the data using the bivariate chi-squared test and multinomial regression. The prevalence of HS overall was 46.9% (S2,16.6%; S3, 30.3%). The prevalence of S3 was highest among Mexican Americans (42.8%), lowest among Blacks (21.6%), 27.6% in other Hispanics, and 30.6% in Whites (P < 0.05). Mexican Americans were about 2 times more likely than Whites to have S2 and S3, while other Hispanics showed no difference from Whites. In an adjusted model, the common risk factors of S2 and S3 were male sex, older ages, high waist-to-hip ratio, body mass index ≥25, and high triglycerides (P < 0.05). Other risk factors for S3 were hemoglobin A1c ≥5.7 and highly sensitive C-reactive protein ≥10 mg/dL (P < 0.05). Conclusion: Our study challenges the paradigm that HS is higher in Hispanics overall; rather, our data show that HS is higher in Mexican Americans and not non-Mexican American Hispanics

Prevalence and Predictors of Nonalcoholic Steatohepatitis Using Multiple Non-Invasive Methods: Data from NHANES III.

ObjectivePatients with nonalcoholic steatohepatitis (NASH) are at risk for developing cirrhosis and hepatic cancer. Currently, the definitive gold-standard method of diagnosing NASH is a liver biopsy, an invasive and costly method. Our objective was to compare three non-invasive methods of identifying NASH by using data on 10,007 subjects from NHANES III (1988-1994) to determine the prevalence and variables associated with NASH, as defined by each non-invasive method.MethodsWe used ultrasound data to identify subjects with moderate-to-severe hepatic steatosis, of whom we identified the NASH population using either the HAIR score, the NASH liver fat score, or the Gholam score, each of which had been validated with liver biopsy. We performed multinomial logistic regression to compare each NASH population to the normal population (those with no-to-mild hepatic steatosis).ResultsWe identified 1136 (9.5%) subjects as having NASH by at least one method and 219 (1.8%) were identified by all 3 methods. Independent of the non-invasive method used, Mexican-Americans (MA) had the highest prevalence of NASH. All three methods identified significant risk factors for NASH (p<0.05), including: elevated waist-to-hip ratio, elevated levels of C-peptide, total cholesterol, or C-reactive protein (CRP).ConclusionWe conclude that the combined non-invasive methods can help identify candidates with a high likelihood of being diagnosed with NASH. Health care providers can screen people with the combined non-invasive methods for the risk factors and identify candidates for interventions, including exercise and/or referral to biopsy

N2Africa Podcaster no. 57 : Putting nitrogen fixation to work for smallholder farmers in Africa: July and August 2019

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