Determining if the vast soil health degradations across the seven major soil groups (orders) of Sub-Saharan Africa (SSA) can be managed on the basis of a one-size-fits-all or location-specific approach is limited by a lack of soil group-based understanding of soil health degradations. We used the relationship between changes in nematode population dynamics relative to food and reproduction (enrichment, EI) and resistance to disturbance (structure, SI) indices to characterize the soil food web (SFW) and soil health conditions of Ferralsol, Lithosol and Nitosol soil groups in Ghana, Kenya and Malawi. We applied bivariate correlations of EI, SI, soil pH, soil organic carbon (SOC), and texture (sand, silt and clay) to identify integrated indicator parameters, and principal component analysis (PCA) to determine how all measured parameters, soil groups, and countries align. A total of 512 georeferenced soil samples from disturbed (agricultural) and undisturbed (natural vegetation) landscapes were analyzed. Nematode trophic group abundance was low and varied by soil group, landscape and country. The resource-limited and degraded SFW conditions separated by soil groups and by country. EI and SI correlation with SOC varied by landscape, soil group or country. PCA alignment showed separation of soil groups within and across countries. The study developed the first biophysicochemical proof-of-concept that the soil groups need to be treated separately when formulating scalable soil health management strategies in SSA.

The co-existence of microbial communities and Meloidogyne hapla populations showing high, medium, and low levels of parasitic variability (PV) in mineral and muck soils with different soil health conditions in Michigan vegetable production fields is established. However, if PV relates or not to bacterial communities is unknown. This study characterized bacterial communities present on and in the body of nine M. hapla field and greenhouse sub-populations isolated from the mineral and muck fields. We utilized a high throughput sequencing of 16S rDNA. Results showed a variable composition (or abundance) of 65 genera in the field and 61 genera in the greenhouse isolates, with 12 genera of unknown and the rest belonging to 14 known functional groups. The medium- and low-PV populations shared more bacterial composition than either one with the high-PV population. Thus, laying a foundation for an in-depth understanding of if the observed associations have any role in cause-and-effect relationships with M. hapla PV.

While numerous studies have evaluated the effects of prenatal pesticide exposure on birth weight, few have examined associations with ultrasound measures of fetal growth, and none have focused on women living with HIV (WLHIV). Because children born to WLHIV face health vulnerabilities related to HIV infection and antiretroviral treatment, we conducted this study to determine whether pesticide exposure contributes further risk to fetal growth. We assessed associations between prenatal exposure to 28 pesticide biomarkers and ultrasound-based fetal growth trajectories and traditional birth outcomes among WLHIV from Brazil and the U.S. We evaluated 153 women living with HIV with prenatal ultrasounds, birth measurements, and urine specimens collected throughout pregnancy. Pesticide biomarkers (including herbicides, insect repellents, neonicotinoids, organophosphate insecticides, and pyrethroids) were quantified using mass spectrometry. Mixed effect linear regression models evaluated associations of geometric mean concentrations with fetal growth outcomes, and linear and logistic regression models assessed associations with birth outcomes. Most pesticides were not associated with meaningful decrements in fetal growth measures or birth outcomes. However, seven pesticides were linked to reductions in fetal growth measures persisting through birth. These included associations with smaller fetal and birth measurements, including head circumference, biparietal diameter, femur length, abdominal circumference, and birth weight Z-score. Two of these pesticides were also associated with increased odds of being small for gestational age. We found that certain pesticides increased the risk of suboptimal growth during pregnancy among WLHIV, highlighting possible additional health risks among children exposed to HIV and related treatments.

BackgroundWhile numerous studies have evaluated the effects of prenatal pesticide exposure on birth weight, few have examined associations with ultrasound measures of fetal growth, and none have focused on women living with HIV (WLHIV).ObjectiveWe assessed associations between prenatal exposure to 28 pesticide biomarkers and ultrasound-based fetal growth trajectories and traditional birth outcomes among WLHIV from Brazil and the U.S.MethodsWe evaluated 153 women living with HIV enrolled between 2017-2020 in the HIV ZIP Study with serial prenatal ultrasounds, birth measurements, and urine specimens collected throughout pregnancy. Pesticide biomarkers (including herbicides, insect repellents, neonicotinoids, organophosphate (OP) insecticides, and pyrethroids) were quantified using mass spectrometry. Mixed effect linear regression models were used to evaluate associations of geometric mean concentrations with fetal growth outcomes, and linear and logistic regression models were used to assess associations with birth outcomes.ResultsMost pesticides were not associated with meaningful decrements in fetal growth measures or birth outcomes. However, 7 pesticides were linked to reductions in one or more fetal growth measures that persisted through birth. These findings included associations with smaller fetal and birth measurements, including head circumference, biparietal diameter, femur length, abdominal circumference, and birth weight Z-score. Two of these pesticides were also associated with increased odds of being small for gestational age.ConclusionsWe found that certain pesticides increased the risk of suboptimal growth during pregnancy among WLHIV, which highlights the importance of documenting these risks among their children who may face compounded health risks from HIV and related treatments.

Summary: Conservation tillage, cover crops, and nutrient amendments are among the regenerative agricultural practices applied to suppress herbivore nematodes (Hvs) and improve soil health for which beneficial nematodes (BNs) are an indicator. Since Hvs and BNs exist in the same environment, quantifying Hvs in ways that parallel BNs could lead to improved ways of managing Hvs and soil health. This study advances concepts of accounting for all Hvs regardless of population density, mode of parasitism or host range and quantifying them on the 1-5 coloniser-persister (cp) ecophysiological scale grouped as cp 2 (Hvs2), cp 3-5 (Hvs35), and the sum of all (HvSum). We tested the effects of 4-year (Y) treatment of tillage (T), winter rye ‘Wheeler’ cover crop (C) and rates 0, 112 or 224 kg ha ⁻¹ nitrogen amendment (N) from inorganic and compost sources on all Hv groups under corn production. The total abundance of the Hv genera was very low, and C and N had no effect, potentially leading to little management concern and dropping the regenerative agricultural practices. When expressed on the ecophysiological scale, however, Hvs2 were only affected by the interaction of C*Y; whereas, conventional tillage, T*Y, N*Y, T*C*N and T*C*N*Y significantly decreased Hvs35, thus showing that the regenerative agricultural practices affect Hvs2 and Hvs35 differently. The cumulative accounting of Hvs grouped as Hvs2 and Hvs35 serves as a foundation for comparing Hvs and BNs on the same ecophysiolocal scale and improves the application of regenerative agricultural practices.