Browsing by Subject "legumes"

Now showing 1 - 3 of 3
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    Biological nitrogen fixation of winter annual legume cover crops in Upper Midwest horticultural cropping systems
    (2018-04) Perrone, Sharon
    Legume cover crops can play a valuable role in maintaining and increasing soil quality and nitrogen availability, but face unique challenges in the Upper Midwest, such as short growing seasons, cold, wet springs, and harsh winters. This study was performed to assess the viability of winter annual legume species in northern climates as a source of nitrogen fertility to a 75-day sweet corn crop (Zea mays convar. saccharata var. rugosa). Treatments included medium red clover (Trifolium pratense), two cold-hardy ecotypes of hairy vetch (Vicia villosa Roth), a cereal rye-hairy vetch biculture (Secale cereale L., Vicia villosa Roth), cereal rye as a non-legume control, and a fallow weed-free control. In 2015-2016, legumes were split into rhizobia inoculated and non-inoculated treatments. In 2016-2017, inoculation treatments were dropped due to no significant findings in biomass production and nodulation between inoculated and non-inoculated treatments. Cover crops were planted in fall 2015 and 2016 at the University of Minnesota Research and Outreach Centers located in Grand Rapids, MN and Lamberton, MN in a randomized complete block design. Total biomass, total nitrogen, and natural 15N abundance were determined for all site years, with nodule mass and number determined in 2015-2016 only. The rye monoculture and biculture produced the most biomass at all site-years ranging from 1.9-3.7 Mg ha-1, while a vetch ecotype (V2) produced as much biomass as the rye monoculture and bicultures in 3 of 4 site-years. Both vetch ecotypes contributed the most nitrogen in 2015-2016, while clover contributed less than rye mono- and bicultures at Grand Rapids in 2016-2017, and there were no significant differences in nitrogen contributions among all treatments in Lamberton in 2016-2017. Hairy vetch ecotype 1 contributed up to 85 kg N ha-1 from aboveground biomass. Data from natural abundance isotopic approaches indicate that 38-103% of vetch tissue N in Grand Rapids and 45-66% of vetch tissue N in Lamberton was derived from atmospheric N fixation, with equal or higher fixation of vetch in biculture at all site-years. Sweet corn yield was equal across all treatments, including a bare ground control. More studies should be performed to enhance N fixation in legume cover crops in the Upper Midwest.
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    Effects of cold temperatures and high tunnel environments on symbiotic nitrogen fixation and growth of winter annual legume cover crops
    (2019-03) Thurston, Charlotte
    We investigated the effect of Upper Midwest winter temperatures on nitrogen contributions of winter annual legume crops via productivity and symbiotic nitrogen fixation (SNF). Projects included: 1) a controlled environment study of growth, nodulation, and SNF in crimson clover (Trifolium incarnatum), Austrian winter pea (Pisum sativum), and hairy vetch (Vicia villosa), and 2) a high tunnel evaluation of four cover crop mixes for productivity, nodulation, and SNF. High tunnel treatments included: a) crimson clover monoculture (T. incarnatum), b) red clover monoculture (Trifolium pratense), c) Austrian winter pea/winter rye biculture (Pisum sativum and Secale cereale), and c) hairy vetch/tillage radish/winter rye mix (V. villosa, Raphanus sativus, and S. cereale). Legume biomass, nodulation, and SNF were limited below 10°C. In high tunnels, lowest biomass and nodulation occurred in mid-winter and lowest SNF in early spring. Delayed spring recovery of SNF suggested that later winter annual cover crop termination could increase nitrogen contributions.
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    Evaluating the Agricultural, Historical, Nutritional, and Sustainable Uses of Pulse Grains and Legumes
    (2018-06) Havemeier, Stefanie
    Pulses are a dry, edible variety of beans, peas, and lentils that have been consumed for 10,000 years. There are many different varieties of pulse grains, including those investigated: black, adzuki, navy, pinto, kidney, mayocoba, mung, faba, and bambara beans; green, yellow and pigeon peas; red and green lentils; chickpeas, cowpeas, and lupins. Pulses are rich in plant-based protein and fiber, as well as micronutrients such as iron and potassium. The satiating effect of both fiber and protein assists in managing weight and combating obesity. The high fiber content and low glycemic index of pulses aid people with diabetes in maintaining blood glucose and insulin levels. Pulse consumption may improve serum lipid levels to reduce the risk of cardiovascular disease. Pulses developed as a member of both the protein and vegetable food groups as a result of its high content of plant-based protein and dietary fiber. The last two revisions of the Dietary Guidelines saw the transformation from the MyPyramid “meat and beans group” to the MyPlate “protein foods group,” a nutrient name rather than a food source. Research suggests that consumers better identify with food source examples rather than nutrient names. The 2015 Dietary Guidelines also came with a new area: sustainable diets. Encouraging the consumption of sustainable food sources, like pulses, is imperative to ensuring a secure, healthy food supply for the U.S. population over time and for future generations.