Browsing by Subject "Crops"
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Item Consumers' willingness-to-pay for perennial grass conversion to renewable energy in South-Central Minnesota.(2010-08) Pham, Matthew VanThere has been an interest in growing perennial grass on marginal croplands to provide electricity and recreational services in the Madelia, Minnesota region. Policymakers and landowners want to know if it is economically feasible for farmers to convert row crops, such as corn and soybean, to perennial crops since the conversion will only take place only under the right economic conditions. A questionnaire was completed by 725 Carver, Dakota, and Scott county residents, which gave a response rate of 29 percent, to determine how much they would be willing-to-pay (WTP) to utilize the recreational services at a converted site. Using the contingent valuation and hypothetical trip cost models, some support exists for the perennial grass conversion. However, 52 percent would not be willing-to-pay for the conversion, and 64 percent would not visit the converted land. Using the estimated WTP amount from the contingent valuation model, calculations were performed to determine the total benefits a farmer would receive from converting to a perennial grass crop. In most cases, a farmer growing corn and soybean crops would not convert due to the higher revenue earned from growing corn and soybean, with rotation. However, the farmer will convert to perennial crops if unlimited credit stacking, or payments for multiple ecological benefits, are allowed.Item Corn earworm (Helicoverpa zea Boddie), cold hardiness, and climate change: implications for future distributions and IPM.(2010-09) Morey, Amy ClaireThe cold hardiness of Helicoverpa zea (Boddie) pupae was assessed using three laboratory methods: supercooling point (SCP), lower lethal temperature (LLTemp), and lower lethal time (LLTime) determination. Mean SCPs for pupae ranged between -16.4°C and -19.5°C, depending on whether pupae were in diapause or had been acclimated. The LLTemp at which 50% mortality occurred (LT50) for diapausing and non-diapausing pupae was -8.8°C and -12.4°C, respectively, though the LLTemp mortality curves were not significantly different. The time until 95% mortality for non-diapausing pupae held at -10°C, -5°C, 0°C, and 5°C was 7.2, 81.6, 502.3, and 1073.4 hrs, respectively. Time until 95% mortality for diapausing pupae held at 0°C and 5°C was 2660.19 and 2796.92 hrs, respectively. Sex did not have an influence on cold hardiness. Diapause greatly enhanced cold hardiness in pupae as indicated by a significantly lower mean SCP and longer time to reach mortality at a given temperature compared to non-diapausing pupae. However, given mean SCP comparisons, acclimation of non-diapausing pupae had a cold hardening effect comparable to diapause. In-field evaluation of overwintering H. zea survival in southern Minnesota showed that temperature was a severely limiting factor in overwintering success, though likely not responsible for complete mortality. Laboratory data, coupled with the field results suggest that a small proportion of pupae may be able to survive in Minnesota. However, field observations also suggest that sufficient degree days may not be available during autumn in southern Minnesota to allow for substantial pupation before the onset of winter, thus eliminating the potential for an overwintering population. Using the cold hardiness data generated for diapausing pupae, the present and future distributions of H. zea in North America were calculated with the modeling software CLIMEX. The resulting maps depicting the current distribution of H. zea from CLIMEX did not agree with what is currently understood for H. zea overwintering distributions and overall geographic suitability; contrary to convention, cold stress is shown to not be a significant constraint to H. zea suitability for most of the U.S. Despite the discrepancies in current projections, the present study corroborated Diffenbaugh et al. (2008) in illustrating a northern expansion of suitability for H. zea, under future climate change. The implications of potential northern expansion in the geographic range of H. zea are discussed within the context of future Integrated Pest Management (IPM) needs for sweet corn, as well as other vegetable and field crops throughout North America.Item Scott County Prime Farmland Mapping Project(Minneapolis: Center for Urban and Regional Affairs, 2009) Schweser, GregItem Soil moisture and soil frost regimes under annual, perennial and agroforestry Crops in Waseca, Minnesota.(2010-03) Byrne, Marin Johanna.The potential for agroforestry and other perennial crops to provide hydrologic benefits is of interest in the Minnesota River Basin, where the landscape is dominated by annual row crops and the river is plagued by water quality and quantity issues. Perennial herbaceous and woody crops are thought to have higher annual consumptive use of water than annual corn-soybean crops, influencing antecedent water status, creating more water storage, potentially decreasing discharge, and reducing the duration of soil frost and prevalence of concrete soil frost in the early spring. Quantification of potential hydrologic benefits is needed to provide support for more sustainable agroforestry and other alternative cropping practices in the basin. To this end, in the summers of 2004 and 2005, biweekly measurements of soil moisture under one annual crop (corn/soybean rotation), two perennial herbaceous crops (perennial flax and Illinois bundleflower) and two woody crops (hybrid hazelnuts and hybrid willow) were taken on replicated experimental plots at the University of Minnesota’s Southern Research and Outreach Center in Waseca, Minnesota. Similar measurements were taken in a stand of mature hybrid poplar and a field planted in a corn/soybean rotation. Likewise, soil frost depth, duration, and type were measured under the same crop types during the intervening winter. Analysis of soil moisture data showed few significant differences in soil moisture between the various crop types on the experimental plots, perhaps due to a combination of the perennial and agroforestry crops being in the establishment phase and unusually wet weather. The mature poplar stand had consistently drier soils than the cornfield during the 2004 season, although these differences disappeared during the course of the 2005 season, likely due to a change in management of understory plant cover in the poplar stand. During the winter, no significant differences in soil frost duration or type were observed, likely due to uniformly wet fall soil conditions, a lack of snow during the coldest part of the winter and rapid spring warm up. Thus, agroforestry and herbaceous perennial crops appear to provide little hydrologic benefit during the establishment phase or in winters with low snowfall, but when mature or in winters with heavier snowfall, could have the potential to provide such benefits.Item Source, Fall 2010(University of Minnesota Extension, 2010) University of Minnesota ExtensionItem Source, Fall-Winter 2014(University of Minnesota Extension, 2014) University of Minnesota ExtensionItem Source, Spring-Summer 2015(University of Minnesota Extension, 2015) University of Minnesota ExtensionItem Source, Summer 2016(University of Minnesota Extension, 2016) University of Minnesota ExtensionItem Source, Winter 2013(University of Minnesota Extension, 2013) University of Minnesota Extension