Showing papers by "Eric C. Brevik published in 2017"

Soil biodiversity and human health

Abstract: Soil biodiversity is increasingly recognized as providing benefits to human health because it can suppress disease-causing soil organisms and provide clean air, water and food. Poor land-management practices and environmental change are, however, affecting belowground communities globally, and the resulting declines in soil biodiversity reduce and impair these benefits. Importantly, current research indicates that soil biodiversity can be maintained and partially restored if managed sustainably. Promoting the ecological complexity and robustness of soil biodiversity through improved management practices represents an underutilized resource with the ability to improve human health.

Ecosystem responses to land abandonment in Western Mediterranean Mountains

Abstract: Agricultural expansion in the Mediterranean resulted in plant and soil degradation due to the intensive use, climate conditions, and rugged terrain. After abandonment, the recovery of vegetation contributed to improvement in soil quality from a hydrological, pedological and geomorphological point of view. This paper shows three examples of ecosystem evolution in abandoned fields in Valencia, Murcia and Andalucia and the application of different methodological approaches that resulted in similar findings. In Valencia, the main responses were the recovery of vegetation after land abandonment and an increase in organic matter and infiltration capacity of soils. In Murcia, with the exception of some terraced areas on marls, where erosion processes following abandonment were important, land abandonment resulted in vegetation recovery, improved soil properties, and reduced surface wash and soil losses. In Andalucia, research along climatological gradients showed the relationship between vegetation patterns and soil moisture and the control that climate exerts on hydrological and erosive behaviour. The experimental research conducted in three different regions in Western Mediterranean demonstrated that abandonment can result in recovery of the geo-ecosystem as vegetation and soil quality improvements were shown. The marls areas in Murcia were the exception with low soil quality and low vegetation cover, and as a consequence showed evidence of high erosion rates after abandonment.

Modeling soil cation exchange capacity in multiple countries

Abstract: Cation exchange capacity (CEC), as an important indicator for soil quality, represents soil's ability to hold positively charged ions. We attempted to predict CEC using different statistical methods including monotone analysis of variance (MONANOVA), artificial neural networks (ANNs), principal components regressions (PCR), and particle swarm optimization (PSO) in order to compare the utility of these approaches and identify the best predictor. We analyzed 170 soil samples from four different nations (USA, Spain, Iran and Iraq) under three land uses (agriculture, pasture, and forest). Seventy percent of the samples (120 samples) were selected as the calibration set and the remaining 50 samples (30%) were used as the prediction set. The results indicated that the MONANOVA (R 2 = 0.82 and Root Mean Squared Error (RMSE) = 6.32) and ANNs (R 2 = 0.82 and RMSE = 5.53) were the best models to estimate CEC, PSO (R 2 = 0.80 and RMSE = 5.54) and PCR (R 2 = 0.70 and RMSE = 6.48) also worked well and the results were very similar to each other. While the most influential variables for the various countries and land uses were different and CEC was affected by different variables in different situations, clay (positively correlated) and sand (negatively correlated) were the most influential variables for predicting CEC for the entire data set. Although the MANOVA and ANNs provided good predictions of the entire dataset, PSO gives a formula to estimate soil CEC using commonly tested soil properties. Therefore, PSO shows promise as a technique to estimate soil CEC. Establishing effective pedotransfer functions to predict CEC would be productive where there are limitations of time and money, and other commonly analyzed soil properties are available.

The Influence of Organic Carbon and pH on Heavy Metals, Potassium, and Magnesium Levels in Lithuanian Podzols

Abstract: Industrial activities can contribute to the accumulation of heavy metals in soils, which could potentially threaten public health and the environment. This research was conducted to investigate the relationships between pH and total organic carbon (TOC) with soil chemical parameters, including exchangeable and total Cu, Zn, Cd, Pb, K, and Mg concentrations in soils near Panevėžys and Kaunas, Lithuania. Principal component regression (PCR) and non-linear regression were used to find statistical relationships between pH, TOC, and the other soil properties studied. The results of correlation tests indicated that pH and TOC had strong relationships with most of the soil properties. The results of PCR [R2 = 0·87, RMSE = 0·046] and non-linear regression [R2 = 0·91, RMSE = 0·041] (pH and the entire parameters), PCR [R2 = 0·777, RMSE = 0·058] and non-linear regression [R2 = 0·871, RMSE = 0·046] (pH and the exchangeable parameters) to model the relationships between pH and soil chemical properties were promising and significant. Exchangeable heavy metal concentrations increased for pH > 5. Even though the relationships between TOC and heavy metals were significant, they were not as powerful as the relationships between pH and these metals. It was concluded that total metal concentrations in the study soils can be predicted by either pH or TOC. Metal mobility could most likely be controlled at the study site by manipulating soil pH and/or TOC. Finally, it is suggested that when there are financial and time limitations, assessment of total exchangeable metal concentrations using soil pH and/or TOC could be productive. Copyright © 2016 John Wiley & Sons, Ltd.

Assessment of agri-spillways as a soil erosion protection measure in Mediterranean sloping vineyards.

Abstract: Suitable vineyard soils enhance soil stability and biodiversity which in turn protects roots against erosion and nutrient losses. There is a lack of information related to inexpensive and suitable methods and tools to protect the soil in Mediterranean sloping vineyards (>25° of slope inclination). In the vineyards of the Montes de Malaga (southern Spain), a sustainable land management practice that controls soil erosion is actually achieved by tilling rills in the down-slope direction to canalize water and sediments. Because of their design and use, we call them agri-spillways. In this research, we assessed two agri-spillways (between 10 m and 15 m length, and slopes between 25.8° and 35°) by performing runoff experiments under extreme conditions (a motor driven pump that discharged water flows up to 1.33 l s-1 for 12 to 15 minutes: ≈1000 l). The final results showed: i) a great capacity by these rills to canalize large amounts of water and sediments; and, ii) higher water flow speeds (between 0.16 m s-1 and 0.28 m s-1) and sediment concentration rates (up to 1538.6 g l-1) than typically found in other Mediterranean areas and land uses (such as badlands, rangelands or extensive crops of olives and almonds). The speed of water flow and the sediment concentration were much higher in the shorter and steeper rill. We concluded that agri-spillways, given correct planning and maintenance, can be a potential solution as an inexpensive method to protect the soil in sloping Mediterranean vineyards.

Role of rock fragment cover on runoff generation and sediment yield in tilled vineyards

Abstract: Summary The soil in conventional Mediterranean vineyards is an active and non-sustainable source of sediment and water. Lack of vegetation cover, small soil organic matter content and intense ploughing result in large rates of erosion in a millennia-old tillage system. There is a need for soil conservation strategies that enable sustainability of wine and grape production; therefore, it is essential to measure the rates and to investigate the processes and factors of soil erosion. This study evaluated factors that can reduce soil losses in traditional Mediterranean vineyards. The investigation was carried out with 96 rainfall simulation experiments at the pedon scale (0.24 m2) to measure soil detachment and runoff yield under low frequency–high magnitude rainfall events of 1 hour at 55 mm hour−1. On average, runoff was 40.6% of the rainfall, and the rate of soil erosion (i.e. amount of soil lost) was 71.5 g m−2. The key factor controlling erosion was the rock fragment cover. There was a clear decrease in soil losses with increased rock fragment cover on the soil surface, but an increase in surface runoff. The results of our study showed that rock fragments at the pedon scale reduced soil erosion in Mediterranean vineyards, but when a layer of embedded rock fragments developed, large rates of runoff were triggered. Highlights We investigated soil erosion factors in Mediterranean vineyards. Rainfall simulation at the pedon scale achieved accurate measurements. Rock fragment cover reduces soil losses. Embedded rock fragment cover will trigger large runoff rates.

Impact of Potentially Contaminated River Water on Agricultural Irrigated Soils in an Equatorial Climate

Abstract: Globally, it is estimated that 20 million hectares of arable land are irrigated with water that contains residual contributions from domestic liquids. This potentially poses risks to public health and ecosystems, especially due to heavy metals, which are considered dangerous because of their potential toxicity and persistence in the environment. The Villavicencio region (Colombia) is an equatorial area where rainfall (near 3000 mm/year) and temperature (average 25.6 °C) are high. Soil processes in tropical conditions are fast and react quickly to changing conditions. Soil properties from agricultural fields irrigated with river water polluted by a variety of sources were analysed and compared to non-irrigated control soils. In this study, no physico-chemical alterations were found that gave evidence of a change due to the constant use of river water that contained wastes. This fact may be associated with the climatic factors (temperature and precipitation), which contribute to fast degradation of organic matter and nutrient and contaminants (such as heavy metals) leaching, or to dilution of wastes by the river.

Reduction of the frequency of herbaceous roots as an effect of soil compaction induced by heavy grazing in rangelands of SW Spain

Abstract: Rangelands in SW Spain constitute the most extensive ranching system on the Iberian Peninsula. During the last few decades, a significant increase in livestock numbers, along with a progressive substitution of cattle for sheep, have led to land degradation processes such as the reduction of grass cover and increased soil compaction in heavily grazed areas. Nevertheless, a better understanding of how soil compaction affects grass production is still needed. In this study, some of the effects of soil compaction due to heavy grazing are analysed, mainly the reduction of the frequency of herbaceous roots and its relationships with bulk density and soil penetration resistance. The study was carried out in 22 fenced areas grazed under different intensities (animal stocking rates: 0.19–15.76 AU ha − 1 ). Undisturbed soil core and bulk samples were collected at 3 depth intervals in order to determine select soil properties (texture, organic matter content, and bulk density). Additionally, soil penetration resistance was quantified at 890 random points at different depths and soil moisture contents. Frequency of herbaceous roots was estimated for each soil horizon in 47 soil profiles and categorized into 4 classes: none, few, common and many. Results showed negative relationships between bulk density (> 10 cm depth) and the content of soil organic matter from 0 to 5 cm ( r = − 0.061, p r = − 0.824, p

Role of rock fragment cover on runoff generation and sediment yield in tilled vineyards

Abstract: &NA; The soil in conventional Mediterranean vineyards is an active and non‐sustainable source of sediment and water. Lack of vegetation cover, small soil organic matter content and intense ploughing result in large rates of erosion in a millennia‐old tillage system. There is a need for soil conservation strategies that enable sustainability of wine and grape production; therefore, it is essential to measure the rates and to investigate the processes and factors of soil erosion. This study evaluated factors that can reduce soil losses in traditional Mediterranean vineyards. The investigation was carried out with 96 rainfall simulation experiments at the pedon scale (0.24 m2) to measure soil detachment and runoff yield under low frequency‐high magnitude rainfall events of 1 hour at 55 mm hour−1. On average, runoff was 40.6% of the rainfall, and the rate of soil erosion (i.e. amount of soil lost) was 71.5 g m−2. The key factor controlling erosion was the rock fragment cover. There was a clear decrease in soil losses with increased rock fragment cover on the soil surface, but an increase in surface runoff. The results of our study showed that rock fragments at the pedon scale reduced soil erosion in Mediterranean vineyards, but when a layer of embedded rock fragments developed, large rates of runoff were triggered. HighlightsWe investigated soil erosion factors in Mediterranean vineyards.Rainfall simulation at the pedon scale achieved accurate measurements.Rock fragment cover reduces soil losses.Embedded rock fragment cover will trigger large runoff rates.

Links Between Soil Security and the Influence of Soil on Human Health

Abstract: Soil is important to human health because of (1) food availability and quality, (2) human contact with various chemicals in soil, (3) human contact with soil organisms, and (4) disposal of wastes. The five dimensions of soil security each have ties to soils and their influence on human health. Capability is related to the ability of soils to produce adequate and high-quality food and filter waste products to provide a clean environment, particularly clean, safe water supplies. Condition influences the nutritional quality of agricultural products produced in a given soil. Capital recognizes that there is value to the services soil provides in promoting human health, costs when soil constituents are detrimental to human health, and significant value in products such as medications that come from soil. Connectivity recognizes that societal interactions with and perspectives of soil influence the value we place on soil and the management strategies we use; this in turn influences human health through capability. Connectivity also recognizes that loss of land as a public good may negatively influence human health. Codification has typically focused on soil and water conservation rather than directly on human health. However, conservation policies have led to improvements in water quality and increased soil health, leading to the production of higher-quality agricultural products in those soils. Therefore, there are significant opportunities to advance soils and human health studies and our understanding of these relationships under the soil security concept.

Soil Mapping and Processes Modeling for Sustainable Land Management

Abstract: Soil maps and models are indispensable tools in sustainable land management. The sustainable land use of our territory is fundamental to providing long-term socio-economic and environmental benefits. The risk of land degradation and corresponding declines in ecosystem services depends on the type of land use. Soil restoration can be extremely expensive, more than the implementation of sustainable land use practices. This is especially important in the context of climate change and the increasing pressure that a growing population places on soil resources, which is a global phenomenon. The objective of this chapter is to show the advantages of using soil mapping and modeling in sustainable land use planning and management. Soil mapping is fundamental to understand the distribution of soil properties, allowing us to implement sustainable practices in vulnerable areas and prevent land degradation. Soil indicators and models provide indispensable information for an accurate evaluation of land degradation status. Alone, or integrated with other disciplines, soil information is extremely important for understanding the causes of land degradation and implementation of sustainable land management. Accurate information and models are key tools for managers and decision makers to implement sustainable land use management policies.

Temporal changes in soil water erosion on sloping vineyards in the Ruwer- Mosel Valley. The impact of age and plantation works in young and old vines

Abstract: Abstract It is well known that rainfall causes soil erosion in sloping German vineyards, but little is known about the effect of age of plantation on soil erosion, which is relevant to understand and design sustainable management systems. In the Ruwer-Mosel valley, young (1- to 4-years) and old (35- to 38-years after the plantation) vineyards were selected to assess soil and water losses by using two-paired Gerlach troughs over three years (2013-2015). In the young vineyard, the overland flow was 107 L m-1 and soil loss 1000 g m-1 in the year of the plantation, and decreased drastically over the two subsequent years (19 L m-1; 428 g m-1). In the old vineyard, soil (from 1081 g m-1 to 1308 g m-1) and water (from 67 L m-1 to 102 L m-1) losses were 1.2 and 1.63 times higher, respectively, than in the young vineyard.

Experiential learning in soil science: Use of an augmented reality sandbox

Abstract: Active participation in science, technology, engineering, and math (STEM) courses maximizes learning while novel technologies allow instructors the opportunity to create interactive activities in the classroom. With this in mind, we incorporated the use of an augmented reality (AR) sandbox at the University of Wyoming to facilitate an experiential learning experience in soil science. The AR sandbox was developed by researchers at the University of California-Davis as part of a project on informal science education in freshwater lakes and watershed science. It is a hands-on display that allows users to create topography models by shaping sand that is augmented in real-time by colored elevation maps, topographic contour lines, and simulated water. It uses a 3-dimensional motion sensing camera that detects changes to the distance between the sand surface and the camera sensor. A short-throw projector then displays the elevation model and contour lines in real-time. Undergraduate students enrolled in the Introductory Soil Science course were tasked with creating a virtual landscape and then predicting where particular soils would form on the various landforms. All participants reported a greater comprehension of surface water flow, erosion, and soil formation as a result of this exercise. They also provided suggestions for future activities using the AR sandbox including its incorporation into lessons of watershed hydrology, land management, soil physics, and soil genesis. K.L. Vaughan, Ecosystem Science and Management Dep., Univ. of Wyoming, 1000 E. University Ave., Laramie, WY 82071; R.E. Vaughan, RedCastle Resources Inc., Salt Lake City, UT 84119; J.M. Seeley, Ellbogen Center for Teaching and Learning, Univ. of Wyoming, 1000 E. University Ave., Laramie, WY 82071. *Corresponding author (karen.vaughan@uwyo.edu). Abbreviations: 3D, 3-dimensional; AR, augmented reality; KeckCAVES, W.M. Keck Center for Active Visualization in the Earth Sciences; STEM, science, technology, engineering, and math; Q, question. Published in Nat. Sci. Educ. 46:160031 (2017) doi:10.4195/nse2016.11.0031 Received 18 Nov. 2016 Accepted 1 June 2017 Supplemental material available online Available freely online through the author-supported open access option Copyright © 2017 American Society of Agronomy 5585 Guilford Road, Madison, WI 53711 USA This is an open access article distributed under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Core ideas • Greater learning occurs when students are active participants. • An augmented reality sandbox belongs in the soil science classroom. • Experiential learning increases student engagement. Studies show that greater learning takes place in science, technology, engineering, and math (STEM) when students are active participants in their learning (Freeman et al., 2014). Researchers uncovered that a primary reason students leave STEM fi elds within the fi rst couple of years of higher education is poor teaching (Seymour and Hewitt, 1997). Traditional lectures and readings are not engaging student interest. Studies show, however, that active participation in STEM courses maximizes learning (Freeman et al., 2014). One way in which this learning is enhanced is by engaging in a cycle of practice and feedback (Ambrose et al., 2010). Participating in an activity and observing the outcomes, provides feedback that guides further practice and understanding. Active learning through the use of multisensory techniques can also help with retention of learning. For example, when a student interacts with information both visually and kinesthetically, information in encoded differently in the brain than through passive listening (Persellin and Daniels, 2014). The acquisition of information through a variety of senses allows the brain to encode information and store memories more deeply (Persellin and Daniels, 2014). In natural resource and environmental sciences education, this often involves field visits to examine phenomena in the natural setting and explore parameters that influence these features (i.e., climate, geomorphology, geologic material, organisms). Field visits, although ideal, are not always feasible for many reasons including cost, time constraints, inclement weather, and scheduling difficulties, among others. Therefore, alternative interactive activities can help increase student engagement and retention in the classroom and laboratory. Bearing this in mind, we incorporated the use of an augmented reality (AR) sandbox in the Introductory Soil Science course (SOIL 2010) at the University of Wyoming to facilitate an experiential learning experience in soil science. As a relatively new technology, the effectiveness of using AR in a soil science classroom has not yet been examined (Reed et al., 2014). Published June 30, 2017

Historical Perspectives on Soil Mapping and Process Modeling for Sustainable Land Use Management

Abstract: Basic soil management goes back to the earliest days of agricultural practices, approximately 9000 BCE. Through time humans developed soil management techniques of ever increasing complexity, including plows, contour tillage, terracing, and irrigation. Spatial soil patterns were being recognized as early as 3000 BCE, but the first soil maps did not appear until the 1700s and the first soil models finally arrived in the 1880s. The beginning of the 20th century saw an increase in standardization in many soil science methods and wide-spread soil mapping in many parts of the world, particularly in developed countries. However, the classification systems used, mapping scale, and national coverage varied considerably from country to country. Major advances were made in pedologic modeling starting in the 1940s, and in erosion modeling starting in the 1950s. In the 1970s and 1980s advances in computing power, remote and proximal sensing, geographic information systems, global positioning systems, statistical and spatial statistics among other numerical techniques significantly enhanced our ability to map and model soils. These types of advances positioned soil science to make meaningful contributions to sustainable land use management as we moved into the 21st century.

Soil Mapping and Processes Models for Sustainable Land Management Applied to Modern Challenges

Abstract: In the context of growing population and global change, increasing demands for food production are an enormous challenge that we face in the modern world. At the same time the need to prevent land degradation, restore lands that are already degraded, and maintain soil quality and health is critical to a sustainable use of land resources. Accurate maps and adequate models are indispensable tools to assist managers, scientists, and decision makers in addressing these challenges. In this chapter, we outline the main impacts of climate change on soils, key adaptation, and mitigation strategies and provide an overview of key issues in sustainable agricultural production as well as land degradation and restoration.

Goal Oriented Soil Mapping: Applying Modern Methods Supported by Local Knowledge

Abstract: Soil mapping is very important for the correct implementation of sustainable land use management. In recent decades, soil mapping methods and data availability have increased exponentially, improving the quality of the maps produced. Despite these advances, local knowledge is a great source of information, refined for centuries and useful for soil mapping and the implementation of a sustainable land management. Local wisdom and experience should be an important aspect of soil mapping because farmers will be one of the major end-users of the maps produced and they should account for the farmers’ reality. However, several problems have been identified in the spatial correlation between folk and scientific classification related to different cultural variables that influence local soil classification.

Mapping Ash CaCO3, pH, and Extractable Elements Using Principal Component Analysis

Abstract: Ash cover in fire-affected areas is an important factor in the reduction of soil erosion and increased availability of soil nutrients. Thus it is important to understand the spatial distribution of ash and its capacity for soil protection and to provide nutrients to the underlying soil. In this work, we aimed to map ash CaCO3, pH, and select extractable elements using a principal component analysis (PCA). Four days after a medium to severe wildfire, we established a grid in a 9 ×27 m area on a west facing slope and took ash samples every 3 m for a total of 40 sampling points. The PCA carried out retained five different factors. Factor 1 had high positive loadings for ash with electrical conductivity, calcium, and magnesium and negative with aluminum and iron. Factor 2 had high positive loadings in total phosphorous and silica and factor 3 in manganese and zinc. Factor 4 had high negative loadings in CaCO3 and pH and finally, factor 5 had high positive loadings in sodium and potassium. The spatial pattern of the factors was different. The Gaussian model was the best fit for factor 1, the linear model the most accurate for factor 4, and the wave hole effect for the loadings of factors 2, 3, and 5. The map generated with the factor scores of factor 1 had a specific pattern, while the map of factor 4 scores had a low accumulation of the explained elements in one area and high in the other. The maps produced from the factor scores of factors 2, 3, and 5 showed a cycled pattern. Ordinary kriging provided the best estimate for factors 1, 2, and 4. Mapping ash in the period immediately after the fire is very important to identify the level of soil protection and the ash nutrient input in the underlying soil.