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Objectives: A study was undertaken to assess the prevalence of undernutrition and associated factors among children under five in two drought-prone areas in Ethiopia. Study design and setting: Through a cross-sectional, mixed-methods approach, data were analysed using multistage random sampling methods. Study subjects and outcome measures: Data were collected on socioeconomic factors, demographic characteristics and anthropometric measurements from 350 households. Height-for-age (HAZ), weight-for-height (WHZ) and weight-for-age (WAZ) z-scores of 304 children, aged 0-60 months, were calculated using the WHO Anthro software. Children with z-scores of less than −2 standard deviations (SDs) for HAZ, WHZ and WAZ were classified as stunted, wasted and underweight respectively. Descriptive statistics, t-tests, correlation and regression analyses were used to assess the relationships between independent variables and stunting and underweight. Results: Prevalence of stunting, wasting and underweight were 49.4%, 13.7% and 37.1% respectively. Among independent variables tested, agroecology was significantly associated with stunting (p = 0.012) and underweight (p < 0.001), while livestock holding was significantly correlated with stunting (p = 0.008) and underweight (p = 0.012). Access to irrigation was also significantly associated with stunting (p = 0.028) and underweight (p = 0.016). However, the prevalence of stunting, wasting and underweight was not significantly associated with household size, landholdings or frequency of sickness. Conclusions: The prevalence of undernutrition within the study areas was higher than the national average for Ethiopia. Lowland areas exhibited the highest rates of undernutrition; consequently, interventions that include the enhancement of livestock holdings and access to irrigation should include agroecological factors in an effort to reduce childhood undernutrition.

Dung excreted by cattle composes a significant portion of the nutrient inputs in a grazed ecosystem and can have wide-ranging effects on soil properties and vegetation. However, little research has been conducted on the nutrient dynamics of excreted dung in situ that has not been disturbed prior to field sampling. In this study, we analyzed 294 dung pats (1–24 days old) collected from a Nebraska Sandhills meadow to determine water-extractable organic carbon (WEOC), water-extractable nitrogen (WEN), water-extractable phosphorus (WEP), and percent dry matter (DM) changes over time. In addition, we investigated if sample handling - frozen storage – and the formation of surface crust during dung field drying affect dung nutrient concentrations. Dung WEOC and WEN both followed exponential decay curves of nutrient loss over time and were modeled as a function of age. In contrast, WEP was poorly correlated with age. The percent dry matter in conjunction with sample WEOC concentration were stronger determinants of WEP than age alone. Freezing samples prior to analysis increased WEOC (37–98%) and WEN (37–123%), but lowered WEP (0.8–65%) compared to the samples from the same dung pat analyzed fresh. The dry surface crusts of dung pats had higher WEOC (98–112%) and WEN (112%) compared to moist interiors (on average, 3 cm from surface). This research provides evidence that dung nutrient concentrations decreased by 73% (WEOC) and 76% (WEN) over 24 days and shows that frozen storage and subsequent thawing for analysis, as well as crust formation during field drying, can significantly affect dung nutrient concentrations and spatial partitioning of dung nutrients.

Phosphorus is often the limiting nutrient to crop production in eastern Africa. Efficient management of P requires an understanding of the factors affecting availability of soil native P and applied fertilizer P. The objectives of this study were (i) to evaluate the relationships between soil properties and P sorption characteristics, and (ii) to assess the effect of termite activities on soil properties and P sorption characteristics. Phosphorus sorption isotherms were determined for 36 soils, including 7 samples from termite mounds and surrounding non-termite soils from Uganda and Mozambique. Ammonium-oxalate extractable Al (Al(ox)) was the most important property explaining over 90% of the variation in P sorption maximum (S(max)) for Uganda and Mozambique soils. However, for the Ethiopia soils 88% of the variation was explained by Mehlich-3 extractable Ca, ammonium-oxalate extractable P (P(ox)), and sand content. The S(max) of Uganda and Mozambique soils increased by 44 to 390% due to increased clay content from termite activities. The higher S(max) of termite mounds implies a greater demand for P fertilizer for low P soils but also a higher P storage capacity and reduced risk of P leaching. Termite mound could be considered as a potential soil amendment.

Vegetation along roadsides reduces soil erosion, increases filtering of water runoff, and acts as a biodiversity corridor. The purpose of this study was to assess soil properties and evaluate their effect on vegetation establishment in roadsides. Furthermore, the effects of shoulder type (paved and unpaved) and time since seeding (0–1 year, 2–4 years, and ≥ 5 years) on soil properties were also evaluated. Roadside soil was sampled from 53 sites in three regions (Panhandle, Southcentral, and Southeastern) in Nebraska, USA. The soil was analyzed for pH, Na, Cl, electrical conductivity, exchangeable sodium percentage, and bulk density and heavy metals. At each site, vegetation was classified into one of four categories, (1) < 10% plant canopy cover; (2) 10 to 50% plant canopy cover; (3) > 50% plant canopy cover dominated by weedy annual grasses and forbs; and (4) > 50% plant canopy cover dominated by seeded perennial grasses. Sodium concentration exceeded the limits that can cause vegetation growth decline in all regions. Sodium and soil bulk density in all regions were clustered with the < 10% plant canopy cover category, meaning that these clustered soil properties have a significant influence on the amount of bare ground and establishment/persistence of vegetation. Heavy metal concentrations (lead, arsenic, zinc, cadmium, and nickel) were less than the thresholder in all regions. It was observed that 12–44% of roadside sites had less than 50% vegetation cover. Roadside soils of paved shoulders had lower Na and Cl concentrations than the roadside soils of unpaved shoulders. The 0–1 year since seeding had higher cadmium, arsenic, and nickel concentrations compared to ≥ 5 years since seeding. Soil degradation declined vegetation establishment along highways, and the degree of soil degradation of these roadsides varied depending on shoulder types and time since seeding.

Soybean [Glycine max (L.) Merr.] rotation has been shown to enhance grain sorghum [Sorghum bicolor (L.) Moench] growth and yield due in part to N contribution. Sorghum grain and stover yield, yield components, soil water and soil NO3–N were measured in a long‐term rotation study in 2003 and 2004 on a Sharpsburg silty clay loam (fine, smectitic, mesic Typic Argiudoll). The objectives were to separate biologically fixed N from other rotation effects on sorghum grain and stover yields, and to relate yield to yield components, soil NO3–N and water contents. The cropping sequences were continuous grain sorghum, and sorghum rotated with non‐nodulating or nodulating soybean. Soil amendment treatments consisted of control (zero), manure (17–25 Mg dry matter ha−1 yr−1), and N (41 kg ha−1 for soybean and 84 kg ha−1 yr−1 for sorghum). Cropping sequence × soil amendment interaction effects were found for most parameters measured. High soil NO3–N following soybean rotation and from amendment application promoted plant growth leading to low soil water content at anthesis, and increased kernel weight, grain and stover yield. Rotation with non‐nodulating soybean without soil amendment increased grain yield by 2.6 to 3.0 Mg ha−1 and stover yield by 1.5 to 1.8 Mg ha−1 over continuous sorghum without soil amendment. Rotation with nodulating soybean further increased grain yield by 1.7 to 1.8 Mg ha−1 and stover yield by 0.6 to 0.9 Mg ha−1. Biologically fixed N effects accounted for only 35 to 41% of enhanced sorghum yield due to crop rotation with soybean. Soil NO3–N during vegetative growth, plant height, soil water content at anthesis and kernel weight were the most important parameters related to sorghum grain yield across cropping sequences and soil amendments.

In 2013, thirty-eight treadle pumps (TPs) were installed as low-cost technology introduction for small-scale irrigation in eastern Ethiopia. This pilot project also trained six farmers on tube well excavation, as well as the installation and maintenance of pumps. In June 2015, researchers visited nine of the thirty-eight TP villages and found only two TPs functioning as originally installed. The rest were replaced with a new technology developed by the trained farmers. Farmers, empowered by training, gained more control in developing technology options tailored to local needs and conditions of their communities. Adopters of the new technology stated that the limited water output and high labor demand of the conventional TP did not optimally fulfil their irrigation water requirements. The new technology had spread quickly to more than one hundred households due to three key factors. First, farmers’ innovative modifications of the initial excavation technique addressed the discharge limitations of the conventional TP by excavating boreholes with wider diameter. Second, local ownership of the new technology, including skills used in well drilling and manufacturing excavation implements, made the modified irrigation technology affordable and accessible to the majority of households. Third, this innovation spread organically without any external support, confirming its sustainability.

Research experiences for undergraduate (REU) students are valuable for exploring STEM professions. Students from underrepresented groups and non-research institutions may not have the opportunities to engage in hands-on research. A primary goal of our Applied Plant Systems REU was to provide authentic research experiences for students who may not have the chance. Mentoring is key to the success of a REU, yet intentional mentoring is not often prioritized. Over three summers, we explored student perception of the value of mentoring within an agricultural STEM REU. Pre- and post-survey responses were analyzed, and we found that the students valued specific aspects of mentoring during their REU. Interestingly, at the end of the REU, the survey result showed that the students placed a higher importance on items such as mentoring being a systematic process and that mentoring is based on friendship. There is clear indication that students know good mentoring when they experience it, even if it is not verbalized. Based on the survey responses and comments from students involved in this REU, we developed practical mentoring items which can be incorporated into research programs to enhance the mentoring experience.

This study abroad program provided an opportunity to enhance the international experience and research skills of University of Nebraska-Lincoln (UNL) students within a multidisciplinary team's research-education goal on improving food security in Ethiopia. The experiential study component of the project included preparatory sessions during the Fall 2015 Semester at the UNL followed by a four- to five-week fieldwork experience in Ethiopia. Teams from the UNL and an Ethiopian university participated in survey data collection and field soil evaluations from farms in the Gerado area of South Wollo, Ethiopia. Having students interact with farmers increased student self-confidence and enhanced their leadership skills. Soil fertility evaluation provided the opportunity for students to apply soil health concepts in a practical setting, thus giving them a fuller understanding of these commonly challenging concepts. Throughout the study experience in Ethiopia, two UNL students wrote reflective journal entries each day and participated in daily wrap-ups. Students also gave presentations to staff at Wollo University and to fellow students and faculty at the UNL. In addition, they completed a final paper integrating the journal material and the experiential research work in Ethiopia. Students experienced cultural immersion while participating in this ongoing research project.

This study abroad program provided an opportunity to enhance the international experience and research skills of University of Nebraska-Lincoln (UNL) students within a multidisciplinary team's research-education goal on improving food security in Ethiopia. The experiential study component of the project included preparatory sessions during the Fall 2015 Semester at the UNL followed by a four- to five-week fieldwork experience in Ethiopia. Teams from the UNL and an Ethiopian university participated in survey data collection and field soil evaluations from farms in the Gerado area of South Wollo, Ethiopia. Having students interact with farmers increased student self-confidence and enhanced their leadership skills. Soil fertility evaluation provided the opportunity for students to apply soil health concepts in a practical setting, thus giving them a fuller understanding of these commonly challenging concepts. Throughout the study experience in Ethiopia, two UNL students wrote reflective journal entries each day and participated in daily wrap-ups. Students also gave presentations to staff at Wollo University and to fellow students and faculty at the UNL. In addition, they completed a final paper integrating the journal material and the experiential research work in Ethiopia. Students experienced cultural immersion while participating in this ongoing research project.

Agricultural soils contribute significantly to nitrous oxide (N₂O) emissions, but little data is available on N₂O emissions from smooth bromegrass (Bromus inermis Leyss.) pastures. This study evaluated soil N₂O emissions and herbage accumulation from smooth bromegrass pasture in eastern Nebraska, USA. Nitrous oxide emissions were measured biweekly from March to October in 2011 and 2012 using vented static chambers on smooth bromegrass plots treated with a factorial combination of five urea nitrogen (N) fertilizer rates (0, 45, 90, 135, and 180 kg ha⁻¹) and two ruminant urine treatments (distilled water and urine). Urine input strongly affected daily and cumulative N₂O emissions, but responses to N fertilizer rate depended on growing season rainfall. In 2011, when rainfall was normal, cumulative N₂O emissions increased exponentially with N fertilizer rate. In 2012, drought reduced daily and cumulative N₂O emission responses to N fertilizer rate. Herbage accumulation ranged from 4.46 Mg ha⁻¹ in unfertilized pasture with distilled water to 16.01 Mg ha⁻¹ in pasture with 180 kg N ha⁻¹ and urine in 2011. In 2012, plots treated with urine had 2.2 times more herbage accumulation than plots treated with distilled water but showed no response to N fertilizer rate. Total applied N lost as N₂O ranged from 0–0.6 to 0.5–1.7 % across N fertilizer rates in distilled water and urine treatments, respectively, and thus, support the Intergovernmental Panel on Climate Change default direct emission factors of 1.0 % for N fertilizer additions and 2.0 % for urine excreted by cattle on pasture.