Browsing by Author "Wood, C. Wesley"

Now showing 1 - 5 of 5
  • Biomass shifts and suppresses weed populations under conservation agriculture
    Mulvaney, Michael J.; Wood, C. Wesley; Price, A. J. (2011)
    Shifting tillage practices to Conservation Agriculture has numerous effects on both the soil and weed populations found in productive areas. The purpose of this research is to "quantify weed suppression of a summer cover crop and organic mulches under no-till collard (Brassica oleracea L.) production during conversion to CA" (authors). The authors examined weed populations, SOC, and collard yield over the course of three years.
  • Carbon and nitrogen mineralization and persistence of organic residues under conservation and conventional tillage
    Mulvaney, Michael J.; Wood, C. Wesley; Balkcom, Kipling S.; Shannon, D. A.; Kemble, J. M. (Madison, WI: American Society of Agronomy, 2010)
    Combining high biomass cover crops with in situ organic mulches may achieve adequate weed control for no-till production, but the persistence and nutrient release rates from cover crops and mulches is unknown. This article describes carbon and nitrogen mineralization rates from three organic mulches (mimosa (Albizia julibrissin Durazz.), lespedeza (Lespedeza cuneata (Dum. Cours.) G. Don)), and oat (Avena sativa L.) straw) and one summer cover crop (soybean (Glycine max (L.) Merr.)). The experiment used litterbag methodology on a Wickham fine sandy loam in Tallassee, AL, USA. Litterbags containing the equivalent of 6.7 Mg ha-1 were placed on the soil surface (to represent conservation tillage) or buried at 10 cm depth (to represent conventional tillage) in October 2007 and retrieved periodically up to a year later. Soybean residue mineralized N at similar rates regardless of placement, but more N was potentially available from surface-placed residues than buried residues, showing that surface placed residues may act as a slow-release N fertilizer. Likewise, C was mineralized more rapidly from buried residues than surface-placed residues. The results quantify the increased amount of C that is sequestered when these residues are used in conservation tillage compared to conventional tillage. This research implies that the use of biomass cover crops and in situ organic mulches could have a measurable impact on carbon retention rates, which will reduce the amount of carbon being released into the atmosphere.
  • Cover crop residue and organic mulches provide weed control during limited-input no-till collard production
    Mulvaney, Michael J.; Price, A. J.; Wood, C. Wesley (Taylor & Francis Group, LLC, 2011)
    Conservation tillage is an effective means to suppress weeds, improve soil quality, and thus enhance food security. However, limited-input producers are reluctant to adopt these practices because of inadequate weed suppression without herbicide use. The purpose of this study was to demonstrate that effective weed control and stable collard yields can be achieved through high-biomass producing cover crops with organic mulches. This system was employed for three consecutive years (2005 - 2008) using forage soybean summer cover crop and mimosa, lespedeza, wheat straw, and a no-mulch control. Mulch use was successful in suppressing broadleaf and sedge weeds over the course of the experiment and demonstrated grass weed suppression after three years. Collard yields were not affected by mulch use and averaged 17,863 kg/ha. The results of this study strongly suggest that limited-input producers may incorporate mulch use in conservation tillage systems without affecting crop yields.
  • Effects of high biomass cover crops and organic mulches on soil properties and collard yield three years after conversion to no-till
    Mulvaney, Michael J.; Wood, C. Wesley; Balkcom, Kipling S.; Shannon, Dennis; Kemble, Joseph (ASA-CSSA-SSSA, 2010)
    Organic producers interested in the adoption of conservation tillage continue to face considerable challenges, particularly with regard to weed control. Previous work demonstrated that high biomass cover crops in conjunction with organic mulches can provide adequate weed control in a no-till system, but the effects of high biomass cover crops and mulches on soil quality during no-till vegetable production has not been investigated. The objective of this study was to determine the effects of organic mulches and forage soybean (Glycine max (L.) Merr. cv. Derry) as a summer cover crop on soil organic carbon (SOC), carbon (C) mineralization, total soil nitrogen (N), aggregate stability, and yield in a no-till system without the use of herbicides during limited-input fall collard (Brassica oleracea L. cv. Champion) production in central eastern Alabama. All treatments, including controls, increased SOC in the 0-5 cm soil depth, indicating that high biomass no-till was more influential on SOC accumulation than the inclusion of summer cover crops or organic mulches. Treatments did not affect collard yield, which averaged 17,863 kg ha-1 yr-1. Mulches applied at 6.7 Mg ha-1 yr-1 did not mineralize nutrients in sufficient quantities to meet collard demands after three years, although the crop appeared healthy. This research highlights the need for careful nutrient management under limited-input no-till vegetable production.
  • Nitrogen and Carbon Mineralization from Peanut Residues under Conservation and Conventional Tillage at Two Locations
    Mulvaney, Michael J.; Wood, C. Wesley; Balkcom, Kipling S.; Meso, Bernard (2011)
    Residue management is an important aspect of crop production systems. Availability of plant residue nitrogen (N) to succeeding crops is dependent on N mineralization rates and therefore on rates of N release during decomposition. Much of the information available on N release rates from peanut (Arachis hypogaea L.) residue is based on controlled-environment studies. The objective of this study was to assess N release rates in the field from the residues of three peanut varieties (NC V-11, GA 02-C and ANorden) at two placements (surface and 10 cm deep) and two locations (Upper Coastal Plain Experiment Station in Edgecombe County, North Carolina and Wiregrass Experiment Station in Henry County, Alabama), representing the northern and southern limits of commercial peanut production in the US. Litterbags containing the equivalent of 3.5 Mg ha-1 were placed in a completely randomized design, blocked by location, with four replications and retrieved periodically up to 335 days after application. Results showed a statistical difference for placement by time (within location) interactions and fit single or double exponential decay models. Buried residues mineralized N at higher rates than surface residues in North Carolina during the initial 50 days of decomposition. After the initial rapid phase of decomposition, there was no difference in rates of N release at either experiment station. Apart from time, no treatment differences were found at the Wiregrass Experiment Station. The data show that N is released quickly after peanut harvest if residue is left in the field.