• Authors:
    • Barbercheck, M. E.
    • Curran, W. S.
    • Ryan, M. R.
    • Ward, M. J.
    • Mortensen, D. A.
  • Source: Weed Science
  • Volume: 59
  • Issue: 1
  • Year: 2011
  • Summary: The activity-density of Amara aenea (DeGeer) and Harpalus pensylvanicus (DeGeer) (Coleoptera: Carabidae) was monitored in an experiment that compared five management treatments representing a range of disturbance frequencies, crops, and aboveground biomass production. In 2004 and 2005, three treatments comprised of multiple summer cover crops were compared to bare fallow and soybean, the latter of which used mechanical cultivation to manage weeds. In 2005 weed seed predation was assessed from June to September in two of the treatments (bare fallow and oat-pea/rye-hairy vetch). Beetle activity-density varied with treatment, time of sampling, and year. In 2004 peak activity-density of A. aenea was highest in the mustard/buckwheat/canola, but there was no difference in H. pensylvanicus activity-density. In 2005 activity-density of H. pensylvanicus was higher in oat-pea/rye-hairy vetch than in soybean treatment. Seed predation rates were relatively consistent across treatments, averaging between 38 and 63%. In fallow and oat-pea/rye-hairy vetch, H. pensylvanicus activity-density accounted for 29 and 33% of the variation in seed predation, respectively. Our findings suggest cover crops have a positive effect on the activity-density of A. aenea and H. pensylvanicus and that disturbance negatively influences their activity-density in the absence of cover crops.
  • Authors:
    • McLean, E.
    • Mclean, K.
    • Bilski, J.
  • Source: Electronic Journal of Environmental, Agricultural and Food Chemistry
  • Volume: 10
  • Issue: 6
  • Year: 2011
  • Summary: A vegetative cover is a remedial technique utilized on coal FA landfills for soil stabilization and for the physical and chemical immobilization of contaminants. Many herbaceous plants, primarily grasses which exhibit rapid growth, are moderately resistant to environmental stress, and are therefore often used as cover crops in environmental restoration and remediation projects. However, there is a great concern, that plants planted or voluntarily growing on media with high content of FA may absorb toxic amounts of Se and/or heavy metals. If such plants are ingested, it may result in toxicity to animals and humans. Despite these objections, the utilization of FA as a growth medium for plants is an attractive alternative for disposal of FA in landfills. We hypothesized that selected plants will grow in media containing FA and/or bottom ash (BA) from several sources. Therefore, the objective of this experiment was to determine the effects of growth media containing FA and/or BA on several cereal crop plants growth including germination, seedlings growth and heavy metals, B and Se accumulation in the seedlings. Two selected coal FA, from Montana semi-bituminous coal and from North Dakota lignite alone or in combination with BA from Montana semi-bituminous coal have been tested as plant growth media (growth media are listed in Table below) for the following plant species: barley ( Hordeum vulgare), oats ( Avena sativa), rye ( Secale cereale), wheat ( Triticum aestivum), regreen; a hybrid between wheatgrass ( Agropyron cristatum) and winter wheat ( Triticum aestivum), and triticale; a hybrid between wheat ( Triticum aestivum) and rye ( Secale cereale). The concentrations of Al, As, B, Ba, Be, Co, Cd, Cr, Cu, Mo, Pb, Sr, Ti, Tl, and V in growth media was determined, and the concentrations of the same elements in young plants was analyzed. Chemical analysis was performed using inductively coupled plasma (ICP) emission spectrophotometry (3). The data were analyzed statistically using ANOVA and Statistical Analysis System. All plant species tested in our experiments showed significant adaptability to the growth on FA based media, with no excessive accumulation of tested elements in plant seedlings. There were noticeable differences in seedlings growth, depending on the type and source of coal ash used. It suggests the necessity to perform pre-plantation tests in case of planning to provide green cover over FA piles. Large scale implementation of plant cover over coal ash landfills will require to conduct in-depth and large scale research.
  • Authors:
    • Brennan, E.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 3
  • Year: 2011
  • Summary: Cone planters (CP) uniformly distribute seed over research plots; however, preparing seed for CP by weighing is time-consuming. This study evaluated (i) the effect of seed preparation method (scooping with a calibrated cup vs. weighing) on population density of monoculture cover crops planted with a CP, (ii) time required for scooping vs. weighing, and (iii) the effect of scooping on segregation of pre-made cover crop mixtures. Monocultures included mustard [ Brassica juncea (L.) Czern.], rye ( Secale cereale L.), common vetch ( Vicia sativa L.), and faba bean ( Vicia faba L.) planted at 1*, 2*, and 4* seeding rates; 1* rates in pure live seed m -2 were 24 (faba bean), 43 (common vetch), 291 (rye), and 310 (mustard). Mixtures contained rye, oat ( Avena sativa L.), barley ( Hordeum vulgare L.), faba bean, common vetch, or pea ( Pisum sativum L.), and by weight included: Mix 1 (10% rye, 90% faba bean), Mix 2 (10% oat, 90% faba bean), Mix 3 (10% barley, 90% faba bean), Mix 4 (10% common vetch, 90% rye), and Mix 5 (10% rye, 25% pea, 30% common vetch, 35% faba bean). Seed preparation method did not affect the population densities of the monocultures. Preparing seed packets was at least two times more time-consuming with the weighing than scooping method. Calibrating cups to scoop within 1% of the desired seed packet weight was not difficult. However, segregation occurred while scooping some mixtures from a bucket whereby smaller-seeded components increased with scooping depth. Simple methods to detect seed segregation in mixtures are discussed.
  • Authors:
    • Mueller-Warrant, G.
    • Dick, R.
    • Banowetz, G.
    • Griffith, S.
    • Whittaker, G.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 4
  • Year: 2011
  • Summary: Understanding the impact of crop rotation and residue management in grass seed production systems on soil quality and, in particular soil C dynamics, is critical in making long-term soil management decisions supporting farm sustainability. The effects of a 6-yr rotation and residue management (high vs. low residue) on soil quality were investigated at three locations in Oregon, each contrasting in soil drainage classification. The crop rotations were continuous perennial grass seed production, grass/legume seed production, and grass/legume/cereal seed production. The grass species grown at each location were different and represented those most commonly produced in each environment; perennial ryegrass ( Lolium perenne L.), tall fescue [ Schedonorus phoenix (Scop.) Holub], and creeping red fescue ( Festuca rubra L.). All three grass seed crop rotations and residue methods maintained high soil quality in conventional or direct seeded soils, but under some situations, soil quality was higher with continuous grass rotation and high residue. Data suggest that straw removal for value-added use, like bioenergy production, can be accomplished in the Pacific Northwest Marine climate without appreciably affecting soil quality. Furthermore, grass seed cropping systems play an important role in soil C storage and enhancement, a valuable ecosystem service in this region where grass seed is produced on land that is not suitable for production of conventional crops that require better-drained soil. We conclude that by nature perennial grass seed crops promote high soil fertility and enriched soil C pools and consequently contribute to the tolerance of these systems to the use of less conservation-oriented crop management methods at times when crop loss could be potentially high. This attribute provides producers greater latitude in selecting soil and crop management options to address issues of soil fertility, pest, weed, or seed certification to minimize economic crop yield losses.
  • Authors:
    • Bow, J.
    • Muir, J.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 4
  • Year: 2011
  • Summary: 'Tifton 85' bermudagrass [ Cynodon dactylon L. (Pers.) * C. transvaalensis Burt Davy] is a warm-season forage used on southeastern U.S. dairy concentrated animal feeding operations (CAFO). Cool-season annual forages need to be identified that can be overseeded into Tifton 85 and remove the greatest quantity of P or N while minimizing suppression of bermudagrass spring regrowth. During 3 yr we overseeded six grass, five legume, and two Brassica spp. on a dairy CAFO Tifton 85 field on a Windthorst fine sandy loam (fine, mixed, active, thermic Udic Paleustalf) containing 83 mg plant-available P kg -1 soil. Hairy vetch ( Vicia villosa Roth.), barley ( Hordium vulgare L.), oat ( Avena sativa L.), and rye ( Secale cereale L.) yielded the most (entry * year interaction P
  • Authors:
    • Brye, K.
    • Smith, A.
    • Fortin, C.
    • Nalley, L.
    • Popp, M.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 4
  • Year: 2011
  • Summary: In this study, we developed a technique for estimating soil C sequestration from crop production with detailed spatial differences in production practices, tillage effects, and soil textures often overlooked when modeling state-level implications of climate change policies. The model also tracks C equivalent (CE) emissions from fertilizer, fuel, and agricultural chemical use. Using Arkansas as an example, a model that maximizes crop returns to producers in conjunction with C offset payments allowed estimation of probable changes in county-level cropping patterns and income as a result of varying C prices. While income ramifications of a C-offset climate change policy are positive, significant uncertainty about resultant greenhouse gas (GHG) effects are demonstrated. Crops included were corn ( Zea mays L.), cotton ( Gossypium hirsutum L.), grain sorghum [ Sorghum bicolor (L.) Moench], soybean [ Glycine max (L.) Merr.], rice ( Oryza sativa L.) and wheat ( Triticum spp.). As a result of this detailed analysis, two caveats are that (i) policy recommendations hinge on a baseline scenario that would change with changes in input and output price levels, with these interactions not modeled within, and (ii) monitoring costs of a C-offset market could be significant.
  • Authors:
    • Kitchen, N.
    • Lal, R.
    • Reicosky, D.
    • Goddard, T.
    • Nearing, M.
    • Groffman, P.
    • Delgado, J.
    • Rice, C.
    • Towery, D.
    • Salon, P.
  • Source: Journal of Soil and Water Conservation
  • Volume: 66
  • Issue: 4
  • Year: 2011
  • Summary: This paper presents an overview of the science on conservation practices that could potentially be used to mitigate and adapt to climate change. Following is a list that summarizes some basic principles based on a review of peer-reviewed scientific publications. Information is given on: the major world challenges related to soil and water conservation; soil and water conservation principles applied to climate change mitigation and adaptation; carbon and nitrogen cycles and agricultural influences on greenhouse gases; conservation practices to mitigate greenhouse gases emissions and adapt to climate change; and current mitigation and adaptation efforts and findings from research.
  • Authors:
    • Kocyigit, R.
    • Rice, C. W.
  • Source: BULGARIAN JOURNAL OF AGRICULTURAL SCIENCE
  • Volume: 17
  • Issue: 4
  • Year: 2011
  • Summary: The soil surface CO 2 flux is the second largest flux in the terrestrial carbon budget after photosynthesis. Plant root and microbial respiration produce CO 2 in soils, which are important components of the global C cycle. This study determined the amount of CO 2 released during spring wheat ( Triticum aestivum L.) growth under no-till (NT) and conventional tillage (CT) systems. This experiment was conducted at Kansas State University North Agronomy Farm, Manhattan, KS, on a Kennebec silt loam. This study site was previously under dry land continuous corn production with NT and CT for more than 10 years. Spring wheat ( Triticum aestivum L.) was planted with two tillage systems (NT and CT) as four replicates in March. Surface CO 2 flux was measured weekly during plant growth. Soil water content at the surface (5 cm) tended to be greater in NT and decreased from planting to harvest. Soil microbial activity at the surface was usually higher in NT and decreased from planting to harvest, while activity was constant in the deeper depths. The higher microbial activity at the surface of NT occurred after 60 days of planting where soil water content was the most limiting factor on microbial activity. Soil CO 2 flux varied in response to changes in soil water content and the variation and magnitude of the increase was greater at higher soil water contents. Conventional tillage released 20% more CO 2 to the atmosphere compare to NT after 10 years in the North American Great Plains Regions.
  • Authors:
    • Provance-Bowley, M.
    • Wyenandt, C. A.
    • Heckman, J. R.
  • Source: Journal of Sustainable Agriculture
  • Volume: 35
  • Issue: 6
  • Year: 2011
  • Summary: When municipal shade tree leaves (MCST-leaf) are used as mulch the residues impact soil fertility for crops in the rotation. Pumpkin (Cucurbita pepo L.), grown near Pittstown, New Jersey, using leaf mulch, was followed in the next year by sweet corn (Zea mays L.) and by a fall-seeded rye (Secale cereale L.) cover crop. A 15 cm layer of MCST-leaf mulch adds an estimated 448 kg ha(-1) of N organically bound within 45 Mg ha(-1) of leaf dry matter. Because of the high C/N ratio, little of this N becomes available in the first growing season as was apparent from the N immobilization and N deficiency temporarily observed when the land was initially cropped to pumpkin. Sweet corn ear size was increased on amended soil compared to unamended soil. Crop responses with both sweet corn and rye indicated that significant amounts of nitrogen became plant available from leaf mulch decomposition. Leaf mulch improves soil fertility for several years after incorporation but in ways not apparent through soil nitrate testing. Besides enhanced N nutrition, sweet corn ear size on MCST-leaf amended soil may be related to other improvements in soil quality such as increased water holding capacity.
  • Authors:
    • Olson, B. L.
    • Schlegel, A. J.
    • Holman, J. D.
    • Maxwell, S. R.
  • Source: Crop Management
  • Issue: June
  • Year: 2011
  • Summary: A common crop rotation in the west-central Great Plains is no-till winter wheat-corn-fallow. Because most of the corn produced is herbicide-tolerant, volunteer corn in fallow is not controlled with glyphosate. This study evaluated the impact of volunteer corn on soil moisture storage in fallow and the succeeding winter wheat crop across three locations in western Kansas from 2008 to 2010. Volunteer corn reduced available soil water at wheat planting in 8 out of 9 site years. On average, available soil water was reduced by 1 inch for each 2,500 volunteer corn plants per acre. Volunteer corn water use reduced wheat tillers in half of the site years. Similarly, volunteer corn reduced wheat yields in half of the site years, and yields fell 1 bu/acre for every 500 volunteer corn plants per acre. When wheat yields were above 70 bu/acre or below 35 bu/acre, other factors affected wheat yield more than the preceding volunteer corn population or available soil water at wheat planting.