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Browsing by Author "Walker, Forbes"

Now showing 1 - 12 of 12
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    Bowen Ratio Energy Balance Measurement of Carbon Dioxide (CO2) Fluxes of No-Till and Conventional Tillage Agriculture in Lesotho
    O'Dell, Deb; Sauer, Thomas J.; Hicks, Bruce B.; Lambert, Dayton M.; Smith, David R.; Bruns, Wendy A.; Basson, August; Marake, Makoala V.; Walker, Forbes; Wilcox, Michael D.; Eash, Neal S. (Open Journal of Soil Science, 2014)
    Global food demand requires that soils be used intensively for agriculture, but how these soils are managed greatly impacts soil fluxes of carbon dioxide (CO2). Soil management practices can cause carbon to be either sequestered or emitted, with corresponding uncertain influence on atmospheric CO2 concentrations. The situation is further complicated by the lack of CO2 flux measurements for African subsistence farms. For widespread application in remote areas, a simple experimental methodology is desired. As a first step, the present study investigated the use of Bowen Ratio Energy Balance (BREB) instrumentation to measure the energy balance and CO2 fluxes of two contrasting crop management systems, till and no-till, in the lowlands within the mountains of Lesotho. Two BREB micrometeorological systems were established on 100-m by 100-m sites, both planted with maize (Zea mays) but under either conventional (plow, disk-disk) or no-till soil management systems. The results demonstrate that with careful maintenance of the instruments by appropriately trained local personnel, the BREB approach offers substantial benefits in measuring real time changes in agroecosystem CO2 flux. The periods where the two treatments could be compared indicated greater CO2 sequestration over the no-till treatments during both the growing and non-growing seasons.
  • Building international partnerships and funding for climate change work in Guatemala, Lesotho, and Mozambique
    Walker, Forbes; Eash, Neal S.; Marake, Makoala V.; Thierfelder, Christian; Basson, August; Rustrick, W. (2015-01-27)
    This poster was presented on October 23rd, 2012 in Cincinnati, Ohio at 3:05 in the afternoon in the Duke Energy Convention Center. This presentation discussed some of the international projects that the University of Tennessee soil science faculty have been involved with in Guatemala, Lesotho, and Mozambique since 2006. Funding for these such project is a differcult task, but funding from these project was made possible by the USDA, USAID, and some alumni donors. Partners include other Universities, International Research Centers, private companies, and local non-governmental organizations.
  • Carbon sequestration in a tilled and untilled maize field in Lesotho, Southern Africa
    Bruns, Wendy A.; Eash, Neal S.; Sauer, T.; Walker, Forbes; West, T. O.; Marake, Makoala V.; Lambert, Dayton M.; Wilcox, Michael D.; Bruns, M. (2015-01-22)
    This presentation was given at the Soil Science Society of America annual meeting on October 19th, 2011 in San Antonio Texas at 10:05 in the morning. No-till agriculture was practiced in Lesotho, Southern Africa, while observing the amount of carbon emissions in the atmosphere during the growing season. Comparisons were made between land under no-till and crop rotation management and land practicing plowed.
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    Conservation agriculture in Mozambique - Literature review and research gaps
    Grabowski, P. P.; Walker, Forbes; Haggblade, S.; Maria, R.; Eash, Neal S. (Agricultural Research Institute of Mozambique, 2013)
    Conservation agriculture (CA) has been promoted in Mozambique since 1996 in order to increase
  • Developing sustainable conservation agriculture for smallholder farmers in Southern Africa
    Eash, Neal S.; Walker, Forbes; Thierfelder, Christian; Marake, Makoala V.; Wilcox, Michael D.; Lambert, Dayton M.; Basson, August (2012)
    This presentation was given at the Soil Science Society of America annual meeting on October 22nd, 2012 in Cincinnati, Ohio at 11:10 in the morning. Conservation agricultural practices were used in Southern Africa's cropping system to improve soil nutrient, improve food security, sequester carbon, and mitigate green house gases.
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    Developing sustainable subsistence smallholder conservation agricultural systems in Lesotho
    Eash, Neal S.; Walker, Forbes; Lambert, Dayton M.; Wilcox, Michael D.; Marake, Makoala V.; Wall, Patrick; Basson, August; Bruns, Wendy A.; Bruns, M. (2011)
    The average subsistence maize yield in Lesotho is very low (less than 0.3 Mg/ha) due to excessive soil erosion rates, low soil fertility, high fertilizer and herbicide cost, moisture/nutrient loss from weed competition, and high labor requirements for hand weeding. The break-even yields for subsistence farmers are approximately 2 Mg/ha or approximately seven times the average yield. This study was conducted to determine the economically viable nitrogen and phosphorus fertilizer rates, planting density, cover crop weed suppression effectiveness, and cultivation methods for maize production. The soils at the experiment site were silty clay loam and located near Mohale's Hoek. The 2009 results indicated that the most expensive smallholder farming method was the hired tractor or animal draft that used hired labor for weeding and was followed closely by likoti ('pothole' method). The most cost effective method was the use of no-till planter. Cover crops suppressed up to 90% of Common Thistle and Cape Tulip (Moraea flaccida), with Grazing Vetch (Vicia sativa) the most effective weed suppressor. Both higher N and P rates and population densities are needed because yields continued to increase at the higher fertilizer rates and population densities. Results from the first year of data suggest that cover crops will be an important component in weed control. Fertilizer N and P rates need to be increased as do the target plant populations.
  • Maize yield response to N, P, K, population, and planting date in Lesotho, Southern Africa
    Bruns, M.; Walker, Forbes; Eash, Neal S.; Jones, W.; Marake, Makoala V.; Wilcox, Michael D.; Lambert, Dayton M.; Stobbe, E. (2011)
    This is an abstract of a presentation at the Soil Science Society of America meeting in San Antinio, Texas on Wednesday October 19th, 2011 at 10:20 in the morning. The presentation includes conservation agriculture techniques used in Lestho in Sub-Sahara Africa to increase soil carbon, in turn increasing production yields. This is an area of minimal data, therefore a variety of farming types were used, which include livelihood farming, small-scale farming, and large-scale farming
  • Managing soil fertility in organic cropping systems: What are your options?.
    Walker, Forbes; Eash, Neal S. (2010)
    Many agricultural producers are considering switching to organic production systems. The successful management of soil fertility through the selection of the appropriate soil amendments is a key component of any successful organic program. The USDA National Organic Program lists numerous plant, animal and mineral based products that can be used in organic production systems. This presentation will be an overview the range of products that can be used to provide the primary nutrients (nitrogen, phosphorus and potassium) in organic productions systems, as well as review some of the limitations and costs associated with their use.
  • Mitigating effects of climate change through conservation agriculture and drought-tolerant open-pollenated maize varieties in Mozambique
    Thierfelder, Christian; Sentimela, P.; Eash, Neal S.; Walker, Forbes (2012)
    This poster was presented on October 23rd, 2012 in Cincinnati, Ohio at four in the after noon. Conservation agriculture practice in southern Africa was combined with drought-tolerant maize in order to benefit of genetic improvement and sustainable land management. Various environmental and crop benefits were found, including better tasting corn and easier pounding of maize for porridge.
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    Smallholder adoption of conservation agriculture and ghg reduction potential in Mozambique and Lesotho
    Lambert, Dayton M.; McNair, W. E.; O'Dell, D.; Bisangwa, E.; Simone, T.; Eash, Neal S.; Wilcox, Michael D.; Walker, Forbes; Marake, Makoala V.; Thierfelder, Christian (2013)
    Current agricultural practices in Mozambique and Lesotho lead to localized externalities and systematic “macro” erosion. However, conservation agriculture, which promotes minimal tillage, intercropping, and maintaining a soil cover, can be applied to moderate erosion and improve food security while sequestering carbon. This presentation examines the greenhouse gas reduction potential Sustainable Agriculture and Natural Resource Management (SANREM) Collaborative Research Support Program’s 5 year project to promote conservation agriculture in Mozambique and Lesotho. It provides graphical comparisons of carbon emissions for tillage and no-tillage systems. Results of a household survey in Mozambique are utilized to examine the probability of the adoption of conservation agriculture related to input use, training, labor constraints, and project support. Farmers who use fertilizer and herbicide and receive credit were found to have the highest adoption rate for conservation agriculture.
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    Smallholder adoption of Conservation Agriculture and GHG reduction potential in Mozambique and Lesotho
    Lambert, Dayton M.; McNair, W. E.; O'Dell, D.; Bisangwa, E.; Simone, T.; Eash, Neal S.; Wilcox, Michael D.; Walker, Forbes; Marake, Makoala V.; Thierfelder, Christian (2013)
    Current agricultural practices in Mozambique and Lesotho lead to localized externalities and systematic “macro” erosion. However, conservation agriculture, which promotes minimal tillage, intercropping, and maintaining a soil cover, can be applied to moderate erosion and improve food security while sequestering carbon. This presentation examines the greenhouse gas reduction potential Sustainable Agriculture and Natural Resource Management (SANREM) Collaborative Research Support Program’s 5 year project to promote conservation agriculture in Mozambique and Lesotho. It provides graphical comparisons of carbon emissions for tillage and no-tillage systems. Results of a household survey in Mozambique are utilized to examine the probability of the adoption of conservation agriculture related to input use, training, labor constraints, and project support. Farmers who use fertilizer and herbicide and receive credit were found to have the highest adoption rate for conservation agriculture.
  • Using conservation agriculture to intensify and stabilize agricultural production in Southern Africa
    Eash, Neal S.; Walker, Forbes; Lambert, Dayton M.; Wilcox, Michael D.; Marake, Makoala V.; Thierfelder, Christian (2013)
    This presentation was given on November 4th, 2013 in Tampa, Florida. The use of conservation agriculture can increase food production sub-Saharan countries. This land is currently receiving excess tillage, which results in gully erosion and other types of land degradation. With sufficient fertilizers of N, P, and K and proper management these lands should be able to have an increase in food production while potentially mitigating carbon dioxide.