Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Tillage (3)
- Crop rotation (2)
- Cropping sequence (2)
- Dryland cropping system (2)
- Nitrogen cycling (2)
-
- Nitrogen fractions (2)
- Burning (1)
- Carbon fractions (1)
- Cercospora carthami (1)
- Cercospora leaf spots (1)
- Cereal stubble (1)
- Chickpea (1)
- Cover crops (1)
- Crop biomass carbon (1)
- Crop residue nitrogen (1)
- Crop yields (1)
- Cropping systems (1)
- Electron microscopy (1)
- Fallow (1)
- Field pea (1)
- Grain yield (1)
- Labile nitrogen fractions (1)
- Lentil (1)
- Management practices (1)
- Microbial activity (1)
- Microbial biomass (1)
- Nitrogen harvest index (1)
- Nitrogen recovery index (1)
- Nitrogen storage (1)
- Northern Great Plains (1)
- Publication Year
Articles 1 - 30 of 30
Full-Text Articles in Entire DC Network
Dryland Soil Nitrogen Cycling Influenced By Tillage, Crop Rotation, And Cultural Practice, Upendra M. Sainju, Andrew W. Lenssen, Thecan Caesar-Tonthat, Jalal D. Jabro, Robert T. Lartey, Robert G. Evans, Brett L. Allen
Dryland Soil Nitrogen Cycling Influenced By Tillage, Crop Rotation, And Cultural Practice, Upendra M. Sainju, Andrew W. Lenssen, Thecan Caesar-Tonthat, Jalal D. Jabro, Robert T. Lartey, Robert G. Evans, Brett L. Allen
Andrew W. Lenssen
Management practices may influence dryland soil N cycling. We evaluated the effects of tillage, crop rotation, and cultural practice on dryland crop biomass (stems and leaves) N, surface residue N, and soil N fractions at the 0–20 cm depth in a Williams loam from 2004 to 2008 in eastern Montana, USA. Treatments were two tillage practices (no-tillage [NT] and conventional tillage [CT]), two crop rotations (continuous spring wheat [Triticum aestivum L.] [CW] and spring wheat-barley [Hordeum vulgaris L.] hay-corn [Zea mays L.]-pea [Pisum sativum L.] [W-B-C-P]), and two cultural practices (regular [conventional seed rates and plant spacing, conventional planting date, …
Sheep Grazing In A Wheat–Fallow System Affects Dryland Soil Properties And Grain Yield, Upendra M. Sainju, Andrew W. Lenssen, Hayes B. Goosey, Erin Snyder, Patrick G. Hatfield
Sheep Grazing In A Wheat–Fallow System Affects Dryland Soil Properties And Grain Yield, Upendra M. Sainju, Andrew W. Lenssen, Hayes B. Goosey, Erin Snyder, Patrick G. Hatfield
Andrew W. Lenssen
Sheep (Ovis aries L.) grazing, an effective method of controlling weeds and pests in a wheat (Triticum aestivum L.)–fallow system, may affect dryland soil properties and wheat yield. We evaluated the effects of fallow management for weed control and soil water conservation (sheep grazing, herbicide application [chemical], and tillage [mechanical]) and cropping sequence (continuous spring wheat [CSW], spring wheat–fallow [SW-F], and winter wheat–fallow [WW-F]) on soil nutrients and chemical properties in the 0- to 60-cm depth and wheat yield. The experiment was conducted in a Blackmore silt loam from 2004 to 2008 in southwestern Montana. Soil P and K concentrations …
Dryland Soil Carbon Dynamics Under Alfalfa And Durum-Forage Cropping Sequences, Upendra M. Sainju, Andrew W. Lenssen
Dryland Soil Carbon Dynamics Under Alfalfa And Durum-Forage Cropping Sequences, Upendra M. Sainju, Andrew W. Lenssen
Andrew W. Lenssen
Forages grown in rotation with or without cereals to sustain dryland soil water content and crop production may influence C dynamics. We evaluated the effect of alfalfa (Medicago sativa L.) and durum (Triticum turgidum L.)-annual forage cropping sequences on above- (stems + leaves) and belowground (roots) biomass C inputs and dryland soil organic C (SOC), particulate total C (PTC), microbial biomass C (MBC), and potential C mineralization (PCM) at the 0–120 cm depth. Cropping sequences were continuous alfalfa (CA), durum-barley (Hordeum vulgare L.) hay (D-B), durum-foxtail millet (Setaria italica L.) hay (D-M), durum-Austrian winter pea (Pisum sativum L.)/barley mixture hay …
Soil Nitrogen Dynamics Under Dryland Alfalfa And Durum–Forage Cropping Sequences, Upendra M. Sainju, Andrew W. Lenssen
Soil Nitrogen Dynamics Under Dryland Alfalfa And Durum–Forage Cropping Sequences, Upendra M. Sainju, Andrew W. Lenssen
Andrew W. Lenssen
Forages grown in rotation with or without cereals to sustain dryland soil water content and crop production may influence N dynamics. We evaluated the effect of alfalfa (Medicago sativa L.) and durum (Triticum turgidum L.)–annual forage cropping sequences on above- (stems + leaves) and belowground (roots) biomass N, dryland soil total N (STN), particulate organic N (PON), microbial biomass N (MBN), potential N mineralization (PNM), NH4–N, and NO3–N contents at the 0- to 120-cm depth in northeastern Montana from 2002 to 2005. Cropping sequences were continuous alfalfa (CA), durum–barley (Hordeum vulgare L.) hay (D-B), durum–foxtail millet (Setaria italica L.) hay …
Tillage Effects On Dryland Soil Physical Properties In Northeastern Montana, J. D. Jabro, Upendra M. Sainju, Andrew W. Lenssen, R. G. Evans
Tillage Effects On Dryland Soil Physical Properties In Northeastern Montana, J. D. Jabro, Upendra M. Sainju, Andrew W. Lenssen, R. G. Evans
Andrew W. Lenssen
We evaluated the effect of no tillage (NT) and conventional tillage (CT) on soil penetration resistance (PR), bulk density (BD), gravimetric moisture content (MC), and saturated hydraulic conductivity (Ks) during the fallow phase of a spring wheat–fallow rotation. The study was conducted on two soils mapped as Williams loam at the Froid and Sidney sites. Soil measurements were made on 19 May, 23 June, and 4 August 2005 at the Froid site and on 6 June and 8 July 2005 at the Sidney site. Tillage had no effect on either soil properties except on the PR at Sidney. However, soil …
Dryland Soil Carbon And Nitrogen Influenced By Sheep Grazing In The Wheat–Fallow System, Upendra M. Sainju, Andrew W. Lenssen, Hayes B. Goosey, Erin Snyder, Patrick G. Hatfield
Dryland Soil Carbon And Nitrogen Influenced By Sheep Grazing In The Wheat–Fallow System, Upendra M. Sainju, Andrew W. Lenssen, Hayes B. Goosey, Erin Snyder, Patrick G. Hatfield
Andrew W. Lenssen
Sheep (Ovis aries) grazing during fallow for weed control in wheat (Triticum aestivum L.)–fallow systems may influence soil C and N levels and grain yields by returning part of consumed crop residue to the soil through feces and urine. We evaluated the effects of fallow management (sheep grazing [grazing], herbicide application [chemical], and tillage [mechanical]) for weed control and soil water conservation and cropping sequence (continuous spring wheat [CSW], spring wheat–fallow [SW-F], and winter wheat–fallow [WW-F]) on soil organic carbon (SOC), inorganic carbon (SIC), total nitrogen (STN), NH4–N, and NO3–N levels at the 0- to 120-cm depth and wheat yield. …
Yield, Quality, And Water And Nitrogen Use Of Durum And Annual Forages In Two-Year Rotations, Andrew W. Lenssen, S. D. Cash, P. G. Hatfield, Upendra M. Sainju, W. R. Grey, Sue L. Blodgett, H. B. Goosey, D. A. Griffith, G. D. Johnson
Yield, Quality, And Water And Nitrogen Use Of Durum And Annual Forages In Two-Year Rotations, Andrew W. Lenssen, S. D. Cash, P. G. Hatfield, Upendra M. Sainju, W. R. Grey, Sue L. Blodgett, H. B. Goosey, D. A. Griffith, G. D. Johnson
Andrew W. Lenssen
Annual spring-seeded forage crops use less water than cereal grains, including durum (Triticum turgidum L. var. durum), and may be suitable to replace summer fallow. We conducted an experiment from 2002 through 2006 comparing yield, quality, and water and N use of durum and three annual forages, barley (Hordeum vulgare L.), barley interseeded with pea [Pisum sativum L. ssp. arvense (L.) Poir.], and foxtail millet [Setaria italica (L.) Beauv.] in 2-yr rotations. Durum in rotation with summer fallow and alfalfa (Medicago sativa L.) were included. Averaged over 5 yr, alfalfa had higher forage yield and quality, water use, and N …
Direct Polymerase Chain Reaction-Based Detection Of Cercospora Beticola In Field Soils, R. T. Lartey, T.C. Caesar-Tonthat, Andrew W. Lenssen, J. Eckhoff, S. L. Hanson, R. G. Evans
Direct Polymerase Chain Reaction-Based Detection Of Cercospora Beticola In Field Soils, R. T. Lartey, T.C. Caesar-Tonthat, Andrew W. Lenssen, J. Eckhoff, S. L. Hanson, R. G. Evans
Andrew W. Lenssen
Cercospora beticola, the causal agent of Cercospora leaf spot of sugar beet, survives as pseudostromata in infected sugar beet residues in the soil. Under optimal conditions, overwintering propagules germinate and produce conidia that are dispersed as primary inoculum to initiate infection in sugar beet. We developed a polymerase chain reaction (PCR) technique for rapid detection of C. beticola in field soils. Total DNA was first isolated from soil amended with C. beticola culture using the PowerSoil DNA Kit. The purified DNA was subjected to PCR in Extract-N-Amp PCR mix with CBACTIN primers over 35 cycles. The amplified products were resolved …
Tillage And Cropping Sequence Impacts On Nitrogen Cycling In Dryland Farming In Eastern Montana, Usa, Upendra M. Sainju, Thecan Caesar-Tonthat, Andrew W. Lenssen, Robert G. Evans, Robert Kolberg
Tillage And Cropping Sequence Impacts On Nitrogen Cycling In Dryland Farming In Eastern Montana, Usa, Upendra M. Sainju, Thecan Caesar-Tonthat, Andrew W. Lenssen, Robert G. Evans, Robert Kolberg
Andrew W. Lenssen
Information on N cycling in dryland crops and soils as influenced by long-term tillage and cropping sequence is needed to quantify soil N sequestration, mineralization, and N balance to reduce N fertilization rate and N losses through soil processes. The 21-yr effects of the combinations of tillage and cropping sequences was evaluated on dryland crop grain and biomass (stems + leaves) N, soil surface residue N, soil N fractions, and N balance at the 0–20 cm depth in Dooley sandy loam (fine-loamy, mixed, frigid, Typic Argiboroll) in eastern Montana, USA. Treatments were no-tilled continuous spring wheat (Triticum aestivum L.) (NTCW), …
Dryland Crop Yields And Soil Organic Matter As Influenced By Long-Term Tillage And Cropping Sequence, Upendra M. Sainju, Andrew W. Lenssen, Thecan Caesar-Tonthat, Robert G. Evans
Dryland Crop Yields And Soil Organic Matter As Influenced By Long-Term Tillage And Cropping Sequence, Upendra M. Sainju, Andrew W. Lenssen, Thecan Caesar-Tonthat, Robert G. Evans
Andrew W. Lenssen
Novel management practices are needed to improve the declining dryland crop yields and soil organic matter contents using conventional farming practices in the northern Great Plains. We evaluated the 21-yr effect of tillage and cropping sequence on dryland grain and biomass (stems + leaves) yields of spring wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), and pea (Pisum sativum L.) and soil organic matter at the 0- to 20-cm depth in eastern Montana, USA. Treatments were no-tilled continuous spring wheat (NTCW), spring-tilled continuous spring wheat (STCW), fall- and spring-tilled continuous spring wheat (FSTCW), fall- and spring-tilled spring wheat-barley (1984–1999) followed …
No Evidence That Bacillus Thuringiensis Genes And Their Products Influence The Susceptibility Of Corn Residue To Decomposition, R. Michael Lehman, Shannon L. Osborne, Kurt A. Rosentrater
No Evidence That Bacillus Thuringiensis Genes And Their Products Influence The Susceptibility Of Corn Residue To Decomposition, R. Michael Lehman, Shannon L. Osborne, Kurt A. Rosentrater
Kurt A. Rosentrater
The possibility that Bacillus thuringiensis (Bt) corn (Zea mays L.) residues resist decomposition compared to non-Bt residues would present direct (soil carbon turnover times) and indirect (changes in tillage practices) effects on carbon budgets in agricultural systems. We evaluated the relative decomposition of residue from two pairs of Bt and non-Bt corn hybrids from different seed manufacturers buried in the root zone of adjacent Bt and non-Bt corn plots over a period of 384 d. We found no persistent differences in residue decomposition among the different hybrids regardless of the seed manufacturer or the presence of the Bt genes (both …
No Differences In Decomposition Rates Observed Between Bacillus Thuringiensis And Non-Bacillus Thuringiensis Corn Residue Incubated In The Field, R. Michael Lehman, Shannon L. Osborne, Kurt A. Rosentrater
No Differences In Decomposition Rates Observed Between Bacillus Thuringiensis And Non-Bacillus Thuringiensis Corn Residue Incubated In The Field, R. Michael Lehman, Shannon L. Osborne, Kurt A. Rosentrater
Kurt A. Rosentrater
Recent speculation of slower residue decomposition for Bacillus thuringiensis (Bt) corn (Zea mays L.) hybrids compared with non-Bt corn hybrids has prompted investigative study. We evaluated the residue decomposition rates of Bt and non-Bt corn hybrids over a period of 22 mo under field conditions using the litter bag technique. The four corn hybrids used were (i) DKC60–16 (Bt+, Cry1Ab protein active against the leptidopteran European corn borer, event MON810), (ii) DKC60–12 (Bt+, Cry3Bb1 protein active against the coleopteran corn rootworm, event MON863), (iii) DKC60–14 (stacked Bt++, Cry1Ab and Cry3Bb1 proteins) and, (iv) DKC60–15 (Bt−, base genetics). The biochemical and …
Long-Term Tillage And Cropping Sequence Effects On Dryland Residue And Soil Carbon Fractions, Upendra M. Sainju, Thecan Caesar-Tonthat, Andrew W. Lenssen, Robert G. Evans, Robert Kolberg
Long-Term Tillage And Cropping Sequence Effects On Dryland Residue And Soil Carbon Fractions, Upendra M. Sainju, Thecan Caesar-Tonthat, Andrew W. Lenssen, Robert G. Evans, Robert Kolberg
Andrew W. Lenssen
Long-term management practices are needed to increase dryland C storage and improve soil quality. We evaluated the 21-yr effects of combinations of tillage and cropping sequences on dryland crop biomass (stems + leaves) returned to the soil, residue C, and soil C fractions at the 0- to 20-cm depth in a Dooley sandy loam (fine-loamy, mixed, frigid, Typic Argiborolls) in eastern Montana. Treatments were no-till continuous spring wheat (Triticum aestivum L.) (NTCW), spring-tilled continuous spring wheat (STCW), fall- and spring-tilled continuous spring wheat (FSTCW), fall- and spring-tilled spring wheat–barley (Hordeum vulgare L.) (1984–1999) followed by spring wheat–pea (Pisum sativum L.) …
Diversified Cropping Systems In Semiarid Montana: Nitrogen Use During Drought, Andrew W. Lenssen, J. T. Waddell, G. D. Johnson, G. R. Carlson
Diversified Cropping Systems In Semiarid Montana: Nitrogen Use During Drought, Andrew W. Lenssen, J. T. Waddell, G. D. Johnson, G. R. Carlson
Andrew W. Lenssen
Improved nitrogen use efficiency would be beneficial to agroecosystem sustainability in the northern Great Plains of the USA. The most common rotation in the northern Great Plains is fallow–spring wheat. Tillage during fallow periods controls weeds, which otherwise would use substantial amounts of water and available nitrogen, decreasing the efficiency of fallow. Chemical fallow and zero tillage systems improve soil water conservation, and may improve nitrogen availability to subsequent crops. We conducted a field trial from 1998 through 2003 comparing nitrogen uptake and nitrogen use efficiency of crops in nine rotations under two tillage systems, conventional and no-till. All rotations …
Dryland Plant Biomass And Soil Carbon And Nitrogen Fractions On Transient Land As Influenced By Tillage And Crop Rotation, Andrew W. Lenssen, Upendra M. Sainju, Thecan Caesar-Thonthat, Jed Waddell
Dryland Plant Biomass And Soil Carbon And Nitrogen Fractions On Transient Land As Influenced By Tillage And Crop Rotation, Andrew W. Lenssen, Upendra M. Sainju, Thecan Caesar-Thonthat, Jed Waddell
Andrew W. Lenssen
Soil and crop management practices may alter the quantity, quality, and placement of plant residues that influence soil C and N fractions. We examined the effects of two tillage practices [conventional till (CT) and no-till (NT)] and five crop rotations [continuous spring wheat (Triticum aestivum L.) (CW), spring wheat–fallow (W–F), spring wheat–lentil (Lens culinaris Medic.) (W–L), spring wheat–spring wheat–fallow (W–W–F), and spring wheat–pea (Pisum sativum L.)–fallow (W–P–F)] on transient land previously under 10 years of Conservation Reserve Program (CRP) planting on the amount of plant biomass (stems + leaves) returned to the soil from 1998 to 2003 and soil C …
Comparative Structural Study Of Leaf Spot Disease Of Safflower And Sugar Beet By Cercospora Beticola, Robert T. Lartey, Andrew W. Lenssen, Robert G. Evans, Soumitra Ghoshroy
Comparative Structural Study Of Leaf Spot Disease Of Safflower And Sugar Beet By Cercospora Beticola, Robert T. Lartey, Andrew W. Lenssen, Robert G. Evans, Soumitra Ghoshroy
Andrew W. Lenssen
Sugar beet and safflower are sometimes rotated or grown side by side in the Sidney, MT region of the Lower Yellowstone River Basin (LYRB). Cercospora beticola and C. carthami infect sugar beet (Beta vulgaris) and safflower (Carthamus tinctorius) respectively. C. beticola is ubiquitous in sugar beet, but C. carthami has not been reported in LYRB. Observations of unusual leaf spots on safflower in Sidney led to investigation and subsequent identification of safflower as a host of C. beticola. We describe a comparative structural study of progression of C. beticola infection and disease development in both sugar beet and safflower. The …
Incorporating Sheep Into Dryland Grain Production Systems I. Impact On Over-Wintering Larva Populations Of Wheat Stem Sawfly, Cephus Cinctus Norton (Hymenoptera: Cephidae), P. G. Hatfield, Sue L. Blodgett, T. M. Spezzano, H. B. Goosey, Andrew W. Lenssen, R. W. Kott, C. B. Marlow
Incorporating Sheep Into Dryland Grain Production Systems I. Impact On Over-Wintering Larva Populations Of Wheat Stem Sawfly, Cephus Cinctus Norton (Hymenoptera: Cephidae), P. G. Hatfield, Sue L. Blodgett, T. M. Spezzano, H. B. Goosey, Andrew W. Lenssen, R. W. Kott, C. B. Marlow
Andrew W. Lenssen
Wheat stem sawfly (WSS), Cephus cinctus Norton (Hymenoptera: Cephidae) is the most damaging insect pest to Montana’s $1 billion dollar per year grain industry. Current WSS control methods are either expensive, reduce wheat yields, or are not effective. Our objective was to compare burning, grazing, tilling, trampling and clipping wheat stubble fields on over-wintering WSS larval populations. Treatments were evaluated in three experiments using a randomized complete block design and four replications at each site. Eight, six, and two sites were used for Experiments 1, 2, and 3, respectively. Contrast statements were used to make pre-planned comparisons among treatments. For …
Sheep Grazing Wheat Summer Fallow And The Impact On Soil Nitrogen, Moisture, And Crop Yield, Andrew W. Lenssen, E. E. Snyder, H. B. Goosey, P. G. Hatfield
Sheep Grazing Wheat Summer Fallow And The Impact On Soil Nitrogen, Moisture, And Crop Yield, Andrew W. Lenssen, E. E. Snyder, H. B. Goosey, P. G. Hatfield
Andrew W. Lenssen
In typical dryland farming areas of Montana, annual precipitation is not sufficient for annual harvest of small grains. Summer fallow in alternate years, is a common method of conserving soil moisture to produce a crop in the following season. Current methods of fallow management are primarily mechanical tillage and spraying with herbicides. Although these methods are effective, they are expensive, making fallow management the highest variable cost associated with dryland grain production. The objectives of this study were to compare the impact of grazing small grains stubble with sheep, as a fallow management tactic, against traditional management practices of chemical …
Carbon Sequestration In Dryland Soils And Plant Residue As Influenced By Tillage And Crop Rotation, Andrew W. Lenssen, Upendra M. Sainju, Thecan Caesar-Thonthat, Jed Waddell
Carbon Sequestration In Dryland Soils And Plant Residue As Influenced By Tillage And Crop Rotation, Andrew W. Lenssen, Upendra M. Sainju, Thecan Caesar-Thonthat, Jed Waddell
Andrew W. Lenssen
Long-term use of conventional tillage and wheat (Triticum aestivum L.)–fallow systems in the northern Great Plains have resulted in low soil organic carbon (SOC) levels. We examined the effects of two tillage practices [conventional till (CT) and no-till (NT)], five crop rotations [continuous spring wheat (CW), spring wheat–fallow (W–F), spring wheat–lentil (Lens culinaris Medic.) (W–L), spring wheat–spring wheat–fallow (W–W–F), and spring wheat–pea (Pisum sativum L.)–fallow (W–P–F)], and Conservation Reserve Program (CRP) planting on plant C input, SOC, and particulate organic carbon (POC). A field experiment was conducted in a mixture of Scobey clay loam (fine-loamy, mixed, Aridic Argiborolls) and Kevin …
Cropping Sequence And Tillage System Influences Annual Crop Production And Water Use In Semiarid Montana, Usa, Andrew W. Lenssen, G. D. Johnson, G. R. Carlson
Cropping Sequence And Tillage System Influences Annual Crop Production And Water Use In Semiarid Montana, Usa, Andrew W. Lenssen, G. D. Johnson, G. R. Carlson
Andrew W. Lenssen
Available water is typically the biggest constraint to spring wheat production in the northern Great Plains of the USA. The most common rotation for spring wheat is with summer fallow, which is used to accrue additional soil moisture. Tillage during fallow periods controls weeds, which otherwise would use substantial amounts of water, decreasing the efficiency of fallow. Chemical fallow and zero tillage systems improve soil water conservation, allowing for increased cropping intensity. We conducted a field trial from 1998 through 2003 comparing productivity and water use of crops in nine rotations under two tillage systems, conventional and no-till. All rotations …
Tillage And Crop Rotation Effects On Dryland Soil And Residue Carbon And Nitrogen, Upendra M. Sainju, Andrew W. Lenssen, Thecan Caesar-Tonthat, Jed Waddell
Tillage And Crop Rotation Effects On Dryland Soil And Residue Carbon And Nitrogen, Upendra M. Sainju, Andrew W. Lenssen, Thecan Caesar-Tonthat, Jed Waddell
Andrew W. Lenssen
Sustainable management practices are needed to enhance soil productivity in degraded dryland soils in the northern Great Plains. We examined the effects of two tillage practices [conventional till (CT) and no-till (NT)], five crop rotations [continuous spring wheat (Triticum aestivum L.) (CW), spring wheat-fallow (W-F), spring wheat-lentil (Lens culinaris Medic.) (W-L), spring wheat-spring wheat-fallow (W-W-F), and spring wheat-pea (Pisum sativum L.)-fallow (W-P-F)], and a Conservation Reserve Program (CRP) on plant biomass returned to the soil, residue C and N, and soil organic C (SOC), soil total N (STN), and particulate organic C and N (POC and PON) at the 0- …
The Potential Role Of Sheep In Dryland Grain Production Systems, H. B. Goosey, P. G. Hatfield, Andrew W. Lenssen, Sue L. Blodgett, R. W. Kott
The Potential Role Of Sheep In Dryland Grain Production Systems, H. B. Goosey, P. G. Hatfield, Andrew W. Lenssen, Sue L. Blodgett, R. W. Kott
Andrew W. Lenssen
In dryland farming areas of Montana, annual precipitation is not sufficient for annual planting of cereal grains. Instead, a crop-summer fallow farming system is used to conserve soil moisture and increase available nitrogen for subsequent crop growth. Managing this summer fallow, either by mechanical means or with herbicides, is the highest variable cost associated with dryland grain production in Montana. Wheat stem sawfly, Cephus cinctus (Hymenoptera: Cephidae) is the most damaging insect pest to Montana’s US$ 1 billion per year grain industry. Weed management is the largest variable cost associated with dryland grain production and summer fallow management. Six fields, …
Clonal-By-Environment Interactions Influence Isoflavonoid Accumulation In Cicer Milkvetch, Andrew W. Lenssen, C. E. Townsend, S. S. Martin
Clonal-By-Environment Interactions Influence Isoflavonoid Accumulation In Cicer Milkvetch, Andrew W. Lenssen, C. E. Townsend, S. S. Martin
Andrew W. Lenssen
Cicer milkvetch (Astragalus cicer L.) is a perennial, nonbloatinducing forage legume adapted to temperate environments. For unknown reasons, however, ruminants grazing cicer milkvetch in pure stands have become photosensitized, or sunburned, in some environments, Isoflavonoids are involved with diverse biological activities, including estrogenism, disease resistance, and, potentially, photosensitization. We conducted a series of studies from 1991 to 1993 to identify factors that influence the accumulation of isoflavonoids. In separate greenhouse studies, elicited leaflets from the parental clones of ‘Monarch’ and. ‘Windsor’ cicer milkvetch were analyzed for isoflavonoid accumulation. Growth chamber studies were conducted to investigate the clonal variability of leaflet …
Forage Yield, Quality, Compatibility, And Persistence Of Warm-Season Grass—Legume Mixtures, G. L. Posler, Andrew W. Lenssen, G. L. Fine
Forage Yield, Quality, Compatibility, And Persistence Of Warm-Season Grass—Legume Mixtures, G. L. Posler, Andrew W. Lenssen, G. L. Fine
Andrew W. Lenssen
Development of compatible, persistent, warm-season grass-legume mixtures could increase forage yield and quality during summer months. We established a trial to determine forage yield, quality, species compatibility, and persistence of binary mixtures of warm-season grasses with selected legumes, five of which are native to the central USA. Grass entries were switchgrass (Panicum virgatum L.), sideoats grama (Bouteloua curtipendula Michx.), and indiangrass [Sorghastrum nutans (L.) Nash]. Legume entries were purple prairieclover [Dalea purpurea Vent.; syn. Petalostemon purpureum (Vent.) Rydb.], roundhead lespedeza (Lespedeza capitata Michx.), leadplant (Amorpha canescens Pursh), Illinois bundleflower [Desmanthus illinoensis (Michx.) MacMill., B. Robins. & Fern.], catclaw sensitive brier …
Diversity Among Rhizobia Effective With Robinia Pseudoacacia L, Janet Mccray-Batzli, William R. Graves, Peter Van Berkum
Diversity Among Rhizobia Effective With Robinia Pseudoacacia L, Janet Mccray-Batzli, William R. Graves, Peter Van Berkum
William R Graves
The diversity of rhizobia that form symbioses with roots of black locust (Robinia pseudoacacia L.), an economically important leguminous tree species, was examined by inoculating seedling root zones with samples of soil collected from the United States, Canada, and China. Bacteria were isolated from nodules, subcultured, and verified to be rhizobia. The 186 isolates varied significantly in their resistance to antibiotics and NaCl, their growth on different carbohydrates, and their effect on the pH of culture media. Most isolates showed intermediate antibiotic resistance, the capacity to use numerous carbohydrates, and a neutral to acid pH response. Isolates had greater similarity …
Basic Alfalfa Germplasms Differ In Nutritive Content Of Forage, Andrew W. Lenssen, E. L. Sorensen, G. L. Posler, L. H. Harbers
Basic Alfalfa Germplasms Differ In Nutritive Content Of Forage, Andrew W. Lenssen, E. L. Sorensen, G. L. Posler, L. H. Harbers
Andrew W. Lenssen
Little information is available regarding comparative forage quality of alfalfa (Medicago sativa L.) leaves and stems of the nine germplasms from which most North American cultivars have been developed. In a greenhouse trial, forage quality of leaves and stems of the nine germplasms was compared when grown in a common environment and harvested at the same phenological stage. Germplasm sources (and representative cultivar) tested were: Indian (Sirsa #9), African (African), Peruvian (Hairy Peruvian), Flemish (DuPuits), Turkistan (Lahontan), Chilean (Kansas Common), M. varia Martin (Grimm), Ladak (Ladak), M. falcata L. (Anik). Leaves of germplasm sources differed for concentrations of neutral detergent …
Resistance To Anthracnose Protects Forage Quality Of Alfalfa, Andrew W. Lenssen, G. L. Posler, E. L. Sorenson, D. L. Stuteville
Resistance To Anthracnose Protects Forage Quality Of Alfalfa, Andrew W. Lenssen, G. L. Posler, E. L. Sorenson, D. L. Stuteville
Andrew W. Lenssen
Anthracnose, caused by Colletotrichum trifolii Bain, decreases forage yield and stand persistence of alfalfa (Medicago sativa L.) throughout much of the USA. Little is known about the effects of anthracnose or host-plant resistance on forage quality, including phenolic monomer concentrations. In a controlled environment, we compared forage quality, including phenolic monomers, of alfalfa cultivars Saranac (susceptible) and Saranac AR (resistant) with and without anthracnose (Race 1). In the absence of inoculation, leaves of the two cultivars did not differ significantly for any parameter measured. Leaves had more total phenolics than did stems. Forage quality of inoculated leaves of Saranac often …
Stratification Not Required For Tree-Of-Heaven Seed Germination, William R. Graves
Stratification Not Required For Tree-Of-Heaven Seed Germination, William R. Graves
William R Graves
Tree-of-heaven (Ailanthus altissima (Mill.) Swingle) seed germination and shoot dry weight were determined after stratifying samaras at 5 and 25 °C for up to 28 days. Seeds of samaras stratified at 5 °C for 0, 4, and 12 days showed 70, 77, and 96% germination, respectively, 7 days after sowing. Fourteen days after sowing, 90% of nonstratified seeds had germinated, but shoot weight of nonstratified seedlings was 16% less than that of seedlings from fruit stratified at 5 °C for 12 days. Germination 7 days after sowing was greater after stratification at 5 °C than at 25 °C, but the …
Sheep Preference For Perennial Glandular-Haired And Eglandular Medicago Populations, Andrew W. Lenssen, E. L. Sorensen, G. L. Posler, L. H. Harbers
Sheep Preference For Perennial Glandular-Haired And Eglandular Medicago Populations, Andrew W. Lenssen, E. L. Sorensen, G. L. Posler, L. H. Harbers
Andrew W. Lenssen
Erect glandular-haired Medicago species and hybrid populations have been developed that possess a high degree of resistance to the alfalfa weevil [Hypera postica (Gyllenhal)] and potato leafhopper [Empoasca fabae (Harris)]. Trials were conducted at the North Agronomy Farm, Manhattan, KS, in June and August 1986 to determine if erect glandular hairs on diverse perennial Medicago populations affect forage preference of sheep (Ovis aries). Glandular-haired (+) and eglandular (−) populations were selected from each of the following: diploids M. prostrata Jacq. and M. glandulosa David (KS94) and tetraploids M. glutinosa Bieb. (KS108), M. sativa L. ✕ M. prostrata (KS159), and M. …
Forage Quality Of Perennial Glandular-Haired And Eglandular Medicago Populations, Andrew W. Lenssen
Forage Quality Of Perennial Glandular-Haired And Eglandular Medicago Populations, Andrew W. Lenssen
Andrew W. Lenssen
No abstract provided.