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Dryland Residue And Soil Organic Matter As Influenced By Tillage, Crop Rotation, And Cultural Practice, Andrew W. Lenssen, Upendra M. Sainju, Thecan Caesar-Tonthat, Jalal D. Jabro, Robert T. Lartey, Robert G. Evans, Brett L. Allen
Dryland Residue And Soil Organic Matter As Influenced By Tillage, Crop Rotation, And Cultural Practice, Andrew W. Lenssen, Upendra M. Sainju, Thecan Caesar-Tonthat, Jalal D. Jabro, Robert T. Lartey, Robert G. Evans, Brett L. Allen
Andrew W. Lenssen
Novel management practices are needed to increase dryland soil organic matter and crop yields that have been declining due to long-term conventional tillage with spring wheat (Triticum aestivum L.)-fallow system in the northern Great Plains, USA. The effects of tillage, crop rotation, and cultural practice were evaluated on dryland crop biomass (stems + leaves) yield, surface residue, and soil organic C (SOC) and total N (STN) at the 0–20 cm depth in a Williams loam (fine-loamy, mixed, superactive, frigid, Typic Argiustolls) from 2004 to 2007 in eastern Montana, USA. Treatments were two tillage practices [no-tillage (NT) and conventional tillage (CT)], …
Sheep Grazing Effect On Dryland Soil Carbon And Nitrogen In The Wheat-Fallow System, Andrew W. Lenssen, Upendra M. Sainju, Hayes B. Goosey, Erin Snyder, Patrick G. Hatfield
Sheep Grazing Effect On Dryland Soil Carbon And Nitrogen In The Wheat-Fallow System, Andrew W. Lenssen, Upendra M. Sainju, Hayes B. Goosey, Erin Snyder, Patrick G. Hatfield
Andrew W. Lenssen
Weed control by sheep grazing during fallow periods in the dryland wheat-fallow system may influence soil C and N levels. The effects of fallow management for weed control and soil water conservation [sheep grazing (grazing), herbicide application (chemical), and tillage (mechanical)] and cropping sequence [continuous spring wheat (CSW), spring wheat-fallow (SW-F), and winter wheatfallow (WW-F)] on wheat biomass (stems + leaves) yield and soil organic C (SOC) and total N (STN) at the 0-120 cm depth was evaluated from 2004 to 2008 in western Montana. Annualized wheat biomass yield was greater in CSW than in SW-F and WW-F from 2004 …
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 …
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 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 …
Incorporating Sheep Into Dryland Grain Production Systems Iii. Impact On Changes In Soil Bulk Density And Soil Nutrient Profiles, P. G. Hatfield, H. B. Goosey, T. M. Spezzano, Sue L. Blodgett, Andrew W. Lenssen, R. W. Kott, C. B. Marlow
Incorporating Sheep Into Dryland Grain Production Systems Iii. Impact On Changes In Soil Bulk Density And Soil Nutrient Profiles, P. G. Hatfield, H. B. Goosey, T. M. Spezzano, Sue L. Blodgett, Andrew W. Lenssen, R. W. Kott, C. B. Marlow
Andrew W. Lenssen
Changes in soil bulk density and soil nutrient profiles are a major concern of dryland grain producers considering grazing sheep on cereal stubble fields. Our objective was to compare burned, grazed, tilled, trampled and clipped wheat stubble fields on changes in soil bulk density and soil nutrient profiles. Treatments were evaluated in a series of three experiments using a randomized complete block design and four replications at each site. Contrast statements were used to make pre-planned comparisons among treatments. For Experiment 1, treatments were fall tilled, fall grazed, spring grazed, fall and spring combined (Fall/Spr) grazed, and an untreated control. …
Incorporating Sheep Into Dryland Grain Production Systems Ii. Impact On Changes In Biomass And Weed Density, P. G. Hatfield, Andrew W. Lenssen, T. M. Spezzano, Sue L. Blodgett, H. B. Goosey, R. W. Kott, C. B. Marlow
Incorporating Sheep Into Dryland Grain Production Systems Ii. Impact On Changes In Biomass And Weed Density, P. G. Hatfield, Andrew W. Lenssen, T. M. Spezzano, Sue L. Blodgett, H. B. Goosey, R. W. Kott, C. B. Marlow
Andrew W. Lenssen
Weed control in fallow management to conserve soil moisture and nutrients is the largest variable cost to dryland grain production. Our objective was to compare burning, grazing, tilling, trampling and clipping wheat stubble fields on changes in total above ground biomass and weed density. Treatments were evaluated in three experiments using a randomized complete block design for each experiment with four replications at each site. Contrasts statements were used to make pre-planned comparisons. For experiment 1, treatments were fall tilled, fall grazed, spring grazed, fall and spring combined (Fall/Spr) grazed, and an untreated control. For grazing treatments, five mature ewes …
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 …
Farming Systems Research On Crop Diversification, Tillage, And Management Effects On Yield, Pests, And Environmental Quality In A Semi-Arid Environment, Andrew W. Lenssen, U. Sainju, T. Caesar-Tonthat, B. Allen, R. Lartey
Farming Systems Research On Crop Diversification, Tillage, And Management Effects On Yield, Pests, And Environmental Quality In A Semi-Arid Environment, Andrew W. Lenssen, U. Sainju, T. Caesar-Tonthat, B. Allen, R. Lartey
Andrew W. Lenssen
Available water, depleted soil quality, and weed competition are important constraints to crop production in the northern Great Plains. The traditional rotation in the region has been spring wheat with summer fallow, which is used to accrue additional soil moisture for the subsequent wheat crop. Tillage during fallow periods controls weeds, which otherwise would use substantial amounts of water and inorganic nitrogen, decreasing the efficiency of fallow and increasing soil erosion. Chemical fallow and zero tillage systems improve soil water status for subsequent crops (Lenssen et al., 2007a), allowing for increased cropping intensity and improved nutrient cycling (Lenssen et al., …