Edge of Field Technology to Eliminate Nutrient Transport from Croplands: Specific Focus on Denitrification Bioreactors
Tile drainage effluent from agriculture fields is beneficial to production agriculture; however, nitrate and phosphate transport from production fields to surface water resources is an environmental concern. The David M. Barton Agriculture Research Center (Cape Girardeau County, Missouri, USA) has a 40 ha controlled subsurface tile drainage/irrigation technology with associated denitrification bioreactor. Nitrate-bearing effluents from the controlled subsurface tile drainage/irrigation technology under a corn (Zea mays L.)-soybean (Glycine max L) rotation is sufficient to be an environmental concern. Nitrate-bearing effluent passage through the denitrification bioreactor typically promotes sufficient nitrate reduction (denitrification) that the bioreactor effluent water is less than 10 mg NO3-N/L. Phosphorus, ammonium-N, and sulfate-S concentrations are not appreciably influenced by denitrification bioreactor passage.
Part of the book: Soil Contamination
Chemical Thermodynamics of Uranium in the Soil Environment
Uranium is present in the soil environment because of human activity, including the usage of U-bearing phosphorus fertilizers. In oxic and many suboxic soil environments, U(VI) is the dominant uranium valence species. With pH, pe (Eh), the partial pressure of CO2, the mineralogy of the adsorbing surfaces and the uranium concentration as the key master variables, U(VI) will predictably participate in hydrolysis, ion-pairing, complexation, ion-exchange, mineral precipitation and adsorption reactions. An extensive listing of thermochemical data is currently available for detailed simulations to assist with model setup, data interpretation and system understanding. In this chapter, simulations of U(VI) hydrolysis with variable pCO2 activities, U(IV) and U(VI) precipitation, U(VI) reduction and U(VI) complexation with carbonate and phosphate assemblages illustrate the usefulness and applicability of simulations in data analysis and experimental design.
Part of the book: Uranium
Lanthanide Soil Chemistry and Its Importance in Understanding Soil Pathways: Mobility, Plant Uptake, and Soil Health
The lanthanide elements or rare earth elements (REEs) are an active soil science research area, given their usage as micro-fertilizers, documented cases of environmental impact attributed to industry/mining, and their ability to identify lithologic discontinuities and reveal active soil processes. To fully understand REEs requires an understanding of their chemical reactivity, both for the individual elements and their behavior as a group of elements. The elements of the lanthanide series, including La and Y, may have subtle to very perceptible chemical differences that when viewed collectively reveal information that gives emphasis to soil processes that clarify soil behavior or soil genesis. This chapter concentrates on lanthanide soil chemistry and shows how the soil chemistry of REEs may support soil science investigations.
Part of the book: Lanthanides
A Large-Scale Wetland Conversion Project in Southeastern Missouri: Sustainability of Water and Soil
Wetland conversion in southeastern Missouri initiated with the Little River Drainage Project (1914–1924) resulting in the permanent drainage and conversion of 5 million acres (2 million hectares) to productive agricultural land. Given that this ancestral wetland conversion has totally replaced the wetland ecosystem with prime agricultural land and with this conversion, the loss of wildlife habitat is nearly complete, the question remains what actions are now possible to restore key wetland soil pathways to support soil health and water quality. Key to any corrective practices involves agricultural producer involvement and commitment. The emerging concept of soil health supports the use of cover crops that promote soil structure development and soil carbon sequestration, each perceived as supporting farm profitability. Government programs supporting field flooding during the off-season supports migratory water fowl. Farming practices such as furrow irrigation and allied technologies for rice production limit aquifer overdraft. Edge of field technology involving riparian strips and denitrification bioreactors support down-stream water quality by limiting nitrate and phosphate off-field migration. The result is that emerging technologies (i) support farm profitability and environmental stewardship and (ii) which are designed specifically to provide farming practice compatibility with the soil and water resources re-establishes some wetland mechanisms appropriate for long-term land and water resource sustainability.
Part of the book: Wetlands Management
Review and Assessment of Organic and Inorganic Rare Earth Element Complexation in Soil, Surface Water, and Groundwater
The lanthanide elements, or rare earth elements (REEs), are an active research area, with increasing attention directed toward soil and water evaluation and protection. Rare earth element concentrations in surface and groundwaters may be appropriately evaluated by partitioning the REEs into (i) a dissolved fraction (REE3+, hydrolysis, and simple anion complexation products) and (ii) REEs associated with inorganic and organic colloidal fractions. Given the total REE concentration and the organic, inorganic, and clastic composition, each fraction of REE concentration and the speciation within the fraction may be thermodynamically simulated to estimate (i) transport potential, (ii) biological availability, and (iii) system reactivity toward changes in pH, oxidation-reduction, chemical composition, mineralogy (facies) changes, or anthropogenic alteration. Chemical thermodynamic simulations using freely available USEPA software are presented to illustrate REE alterations attributed to pH changes, inorganic and organic adsorption, mineral precipitation, and oxidation-reduction. The purpose is to position researchers to better anticipate REE reactivity and transport potential in aquatic and soil resources.
Part of the book: Rare Earth Elements and Their Minerals
Soil Genesis of Histosols and Gelisols with a Emphasis on Soil Processes Supporting Carbon Sequestration
Based on the U.S. Soil Taxonomy Histosols are soils that have a histic epipedon, which is a surface horizon that exhibits a sufficient abundance of soil organic matter to be distinctively different than other soil orders predominantly composed of clastic materials. Gelisols are soils that have permafrost, with histels being a suborder that is dominated by organic materials. Collectively, these soil orders are abundant in peatland ecosystems. The abundance of soil organic material is primarily a consequence of climate, topography, hydrology, vegetation. Peatland ecosystems have been a major research arena; however, added research attention is being directed to the potential release of carbon because of accelerated climate change. This review focuses of the structure and dynamics of organic soils and an understanding of their creation, evolution and ultimate fate. Attention is focused on degraded peatland net primary productivity because of potential forthcoming differences attributed to rainfall, temperature, vegetation, hydrology and permafrost disappearance.
Part of the book: Environmental Issues and Sustainable Development
Integrating Ecological Site Descriptions with Soil Morphology to Optimize Forest Management: Three Missouri Case StudiesView all chapters
Academics and University Extension personnel have experience with soil mapping and providing soil suitability interpretations; however, a more efficient information conveyance to land custodians is desired to support informative land management applications. In the USA each state, in concert with the United States Department of Agriculture, has embarked on developing an online format linking soil survey with ecological site descriptions to provide information for forest and rangeland management to encourage soil protection - health and optimizing ecological services on individual land parcels. In this Missouri-based manuscript, we discuss three cases where soils and their associated ecological site descriptions provide land custodians information concerning their logical reference state vegetation community and detail land management decisions that transform the reference vegetation community to a different vegetation community. With each case, landscapes and their associated vegetations communities are potentially partitioned by soil, physiography, hydrology, and other attributes.
Part of the book: Environmental Management