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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 …
Regional Assemblages Of Lygus (Heteroptera: Miridae) In Montana Canola Fields, Andrew W. Lenssen, R. A. Ritter, Sue L. Blodgett, M. L. Taper
Regional Assemblages Of Lygus (Heteroptera: Miridae) In Montana Canola Fields, Andrew W. Lenssen, R. A. Ritter, Sue L. Blodgett, M. L. Taper
Andrew W. Lenssen
Sweep net sampling of canola (Brassica napus L.) was conducted in 2002 and 2003 to determine Lygus (Heteroptera: Miridae) species composition and parasitism levels in four regions of Montana. Regardless of region or seasonal change, Lygus elisus (Van Duzee) was the dominant species in all canola fields sampled, averaging 60–99% of the total adult populations. Lygus borealis (Kelton), Lygus keltoni (Schwartz) and Lygus lineolaris (Palisot) were detected at much lower levels. Total lygus population density was greatest in the southwest and central regions. The northeast and southwest regions had the greatest lygus species diversity. The proportion of L. elisus increased …
Effects Of Tillage On Microbial Populations Associated To Soil Aggregation In Dryland Spring Wheat System, Andrew W. Lenssen, Thecan Caesar-Tonthat, Anthony J. Caesar, Upendra M. Sainju, John F. Gaskin
Effects Of Tillage On Microbial Populations Associated To Soil Aggregation In Dryland Spring Wheat System, Andrew W. Lenssen, Thecan Caesar-Tonthat, Anthony J. Caesar, Upendra M. Sainju, John F. Gaskin
Andrew W. Lenssen
Tillage may influence the microbial populations involved in soil aggregation.We evaluated the effects of no till (NT) and conventional tillage (CT, tillage depth about 7 cm) continuous spring wheat system on culturable heterotrophic bacterial communities predominant in microaggregates (0.25e0.05 mm) and on soil-aggregating basidiomycete fungi in aggregate-size classes (4.75e2.00, 2.00e0.25, and 0.25e0.05 mm) at 0e20 cm depth of a Williams loam (fine-loamy, mixed, Typic Argiustolls) in dryland Montana, USA. Enzyme-linked immunosorbent assay used to quantify antigenic response to basidiomycete cellwalls,was higher in NT than in CT in 4.75e2.00 mm size class in 2007 and higher in all classes and years …
Management Strategies To Improve Yield And Nitrogen Use Of Spring Wheat And Field Pea In The Semi-Arid Northern Great Plains Usa, Andrew W. Lenssen, Brett Allen, Upendra Sainju, Thecan Caesar, Robert Lartey, Robert Evans
Management Strategies To Improve Yield And Nitrogen Use Of Spring Wheat And Field Pea In The Semi-Arid Northern Great Plains Usa, Andrew W. Lenssen, Brett Allen, Upendra Sainju, Thecan Caesar, Robert Lartey, Robert Evans
Andrew W. Lenssen
Available water and N fertility are primary constraints to crop production in the northern Great Plains of the USA. A field trial was initiated in 2004 to compare four crop rotations in a complete factorial of two tillage and two management systems. Rotations were continuous spring wheat (SW), pea-SW, barley hay-pea-SW, and barley hay-corn-pea-SW. Tillage systems were no till and field cultivator tillage, while management systems were conventional and ecological. Conventional management included broadcast nitrogen fertilizer, standard seeding rates, and short stubble height. Ecological management practices varied by crop, and included banded nitrogen fertilizer for cereals, increased seeding rate, delayed …