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Full-Text Articles in Agriculture

What Contributions Are Invasive Plant Species Making To Ecosystem Services?, Stephen L. Young Mar 2010

What Contributions Are Invasive Plant Species Making To Ecosystem Services?, Stephen L. Young

West Central Research and Extension Center, North Platte

Invasive plant species can establish in diverse environments, and, with the increase in human mobility, they are no longer restricted to isolated pockets in remote parts of the world. Cheatgrass (Bromus tectorum L.) in rangelands, purple loosestrife (Lythrum salicaria L.) in wetlands, and tamarisk (Tamarix spp.) in riparian areas are examples of invasive plant species that are common to the United States and can be found in monocultures and patches covering many thousands of hectares. Across the world, invasive plant species like water hyacinth (Eichhornia crassipes), cogon grass (Imperata cylindrica), and mile-a-minute weed …


Effects Of Maternal Nutrition On Conceptus Growth And Offspring Performance: Implications For Beef Cattle Production, Richard N. Funston, David M. Larson, K. A. Vonnahme Jan 2010

Effects Of Maternal Nutrition On Conceptus Growth And Offspring Performance: Implications For Beef Cattle Production, Richard N. Funston, David M. Larson, K. A. Vonnahme

West Central Research and Extension Center, North Platte

Developmental programming is the concept that a maternal stimulus or insult at a critical period in fetal development has long-term effects on the offspring. Historically, considerable effort has been made to understand how nutrition influences health and productivity during the postnatal period. Whereas maternal nutrition during pregnancy plays an essential role in proper fetal and placental development, less is known about how maternal nutrition affects the health and productivity of the offspring. Conceptus growth is sensitive to direct and indirect effects of maternal dietary intake. Even from the earliest stages of embryonic life, when nutrient requirements for conceptus growth are …


Tillage And Crop Residue Affect Irrigation Requirements, Simon Van Donk Jan 2010

Tillage And Crop Residue Affect Irrigation Requirements, Simon Van Donk

West Central Research and Extension Center, North Platte

Practicing less tillage and retaining more crop residue on the soil surface can reduce the rate of evaporation of water from the soil. These practices also increase the amount of soil water by increasing the amount of water that infiltrates into the soil and decreasing the amount that runs off across the soil surface. Less tillage and more residue coverage can significantly reduce the amount of irrigation water needed to grow a crop.


Effect Of Crop Residue On Soil Water Content And Yield Of Deficit-Irrigated Corn And Soybean, Simon Van Donk, Steven R. Melvin, Jim Peterson, Don Davison Jan 2010

Effect Of Crop Residue On Soil Water Content And Yield Of Deficit-Irrigated Corn And Soybean, Simon Van Donk, Steven R. Melvin, Jim Peterson, Don Davison

West Central Research and Extension Center, North Platte

It is believed that reduced tillage, with more crop residue on the soil surface, conserves water, especially in arid and semi-arid climates. However, the magnitude of water conservation is not clear. In 2007, a study was initiated on the effect of residue on soil water content and crop yield at North Platte, Nebraska. The experiment was conducted on plots planted to field corn (Zea mays L.) in 2007 and 2008, and soybean (Glycine max) in 2009. There were two treatments: residue-covered soil and bare soil. Bare-soil plots were created in April 2007 by using a dethatcher …


Price Discovery In Nebraska Cattle Markets, Matt Stockton, David A. Bessler, Roger K. Wilson Jan 2010

Price Discovery In Nebraska Cattle Markets, Matt Stockton, David A. Bessler, Roger K. Wilson

West Central Research and Extension Center, North Platte

Monthly observations on prices from 10 weight/gender classifications of Nebraska beef cattle are studied in an error correction model (ECM) framework. This study attempts a replication of the 2003 paper on Texas prices by Bessler and Davis, where they find medium heifers (600–700 lb) at the center of price discovery. Using the ECM results Nebraska light steers are found to be weakly exogenous, with the innovation accounting results showing marked differences. Industry structure, production choices, and animal type and breeding herd differences between Texas and Nebraska are proposed as plausible reasons for partial (or incomplete) success at replication.


Crop Residue Cover Effects On Evaporation, Soil Water Content, And Yield Of Deficit‐Irrigated Corn In West‐Central Nebraska, Simon Van Donk, Derrel L. Martin, Suat Irmak, Steven R. Melvin, Jim Peterson, Don Davison Jan 2010

Crop Residue Cover Effects On Evaporation, Soil Water Content, And Yield Of Deficit‐Irrigated Corn In West‐Central Nebraska, Simon Van Donk, Derrel L. Martin, Suat Irmak, Steven R. Melvin, Jim Peterson, Don Davison

West Central Research and Extension Center, North Platte

Competition for water is becoming more intense in many parts of the U.S., including west‐central Nebraska. It is believed that reduced tillage, with more crop residue on the soil surface, conserves water, but the magnitude of water conservation is not clear. A study was initiated on the effect of residue on soil water content and corn yield at North Platte, Nebraska. The experiment was conducted in 2007 and 2008 on plots planted to field corn (Zea mays L.). In 2005 and 2006, soybean was grown on these plots. There were two treatments: residue‐covered soil and bare soil. Bare‐soil plots …


Weed Control In Organic Cropping Systems, Stephen L. Young Jan 2010

Weed Control In Organic Cropping Systems, Stephen L. Young

West Central Research and Extension Center, North Platte

Organic producers and many conventional producers rank weed control as their number one production cost. For organic producers particularly, weed control has become increasingly important as organic production has increased its market share. According to the USDA Census of Agriculture, in 2005, for the first time, all 50 states had certified organic farmland, with over 1.6 million total ha (4 million acres) dedicated to organic production systems. In 2006, four major universities in the United States offered new degree programs in organic agriculture with the anticipation that, in five to six years, organic crops will comprise 5 to 10 percent …


Estrus Synchronization And Periconceptual Supplementation Affect The Profitability Of A Replacement Heifer Enterprise, D. M. Larson, R. D. Richardson, K. H. Ramsay, R. N. Funston Jan 2010

Estrus Synchronization And Periconceptual Supplementation Affect The Profitability Of A Replacement Heifer Enterprise, D. M. Larson, R. D. Richardson, K. H. Ramsay, R. N. Funston

West Central Research and Extension Center, North Platte

Experiments evaluated estrus synchronization and periconceptual supplementation on pregnancy rate and calf production. Approximately one-half of heifers in 2 pastures (yr 1) or 4 pastures (yr 2) were injected with prostaglandin F (PGF; n = 1,182) or not (NPGF; n = 1,208) 5 d after fertile bulls were introduced for 25 d. In yr 2, a total of 1,230 heifers were randomly assigned to 1 of 4 pastures; 2 received a supplement providing 100 g/d of Ca propionate (1.4 kg/d, 20% CP) 2 d before through 19 d after bull exposure and 2 did not in a 25-d breeding …


Effect Of Crop Residue On Soil Water Content And Yield Of Deficit-Irrigated Corn And Soybean, Simon Van Donk, Steven R. Melvin, James L. Petersen, Don Davison Jan 2010

Effect Of Crop Residue On Soil Water Content And Yield Of Deficit-Irrigated Corn And Soybean, Simon Van Donk, Steven R. Melvin, James L. Petersen, Don Davison

West Central Research and Extension Center, North Platte

It is believed that reduced tillage, with more crop residue on the soil surface, conserves water, especially in arid and semi-arid climates. However, the magnitude of water conservation is not clear. In 2007, a study was initiated on the effect of residue on soil water content and crop yield at North Platte, Nebraska. The experiment was conducted on plots planted to field corn (Zea mays L.) in 2007 and 2008, and soybean (Glycine max) in 2009. There were two treatments: residue-covered soil and bare soil. Bare-soil plots were created in April 2007 by using a dethatcher and …


Pollen Interception By Linyphiid Spiders In A Corn Agroecosystem: Implications For Dietary Diversification And Risk-Assessment, Julie A. Peterson, Susan Romero, James D. Harwood Jan 2010

Pollen Interception By Linyphiid Spiders In A Corn Agroecosystem: Implications For Dietary Diversification And Risk-Assessment, Julie A. Peterson, Susan Romero, James D. Harwood

West Central Research and Extension Center, North Platte

Dietary diversification, including consumption of plant tissues such as pollen, can enhance the fecundity of generalist predators, resulting in improved control of pest prey. Supplemental pollen feeding has been observed in many natural enemies, including sheet-web spiders (Araneae: Linyphiidae), which represent a major component of food webs in agroecosystems. Their horizontal, ground-based webs have the potential to intercept pollen grains during anthesis of crop plants, providing the opportunity for consumption of pollen to occur. In laboratory feeding trials, Frontinella communis and Tennesseellum formicum (Araneae: Linyphiidae) readily fed on pollen grains dusted on their webs, with 82 and 92% of spiders …