Harnessing Cover Crops to Address Unique Farm Needs and Achieve Maximum Benefits
Applied Research
Sarah Hirsh
Agent
University of Maryland
Princess Anne
Abstract
Cover crops can provide various benefits, such as building soil organic matter, scavenging nutrients, or controlling pests such as weeds. Since cover crops are not a primary source of farm income, farmers may spend less time planning and managing them when compared to cash crops. We hypothesized that designing cover crops with a particular purpose in mind, extending the cover crop growth window, and considering environmental constraints and the capacity of the farm and farmer would result in more productive and functional cover crops. Extension educators collaborated with farmers to plan cover crops. Farmers planted cover crops in the late-summer to fall planting window and managed cover crops until spring termination. Extension educators measured cover crop fall and spring biomass, and spring nitrogen and carbon content. In year one, 11 farmers collaborated, planting 27 cover crop fields. In year two, 20 farmers collaborated, planting 56 cover crop fields. Farmers primary purposes for cover crops included building organic matter, contributing nitrogen, controlling weeds and other pests, and eliminating black plastic. Fall cover crop biomass from 69 fields ranged from 28 lb/acre to 2887 lb/acre, with an average of 521 lb/acre. Spring cover crop biomass from 83 fields ranged from 156 lb/acre to 8659 lb/acre, with an average of 2213 lb/acre. Cover crop biomass positively correlated with the number of spring growth days. Nitrogen in spring biomass from 56 fields ranged from 2 lb/acre to 124 lb/acre, with an average of 37 lb/acre. Based on 56 fields, cover crop carbon to nitrogen ratio differed according to the cover crop species composition, with grass and/or brassica cover crops > cover crop mixes that included a legume > pure legume cover crops. In conclusion, despite all farmers engaging in cover crop planning, cover crop biomass, nitrogen content, and carbon to nitrogen ratio greatly varied across operations. Extending the cover crop season was important for increasing biomass and functionality. In order to achieve the targeted purpose of the cover crop, farmers often had to modify plans and actively manage cover crops, for example through re-seeding, extending the season later than anticipated, or applying selective herbicides.
Poster has NOT been presented at any previous NACAA AM/PIC
This poster is being submitted for judging. It will be displayed at the AM/PIC if not selected as a State winner. The abstract will be published in the proceedings.
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Authors: Sarah Hirsh, Haley Sater, Dwayne Joseph, Shannon Dill, Jennifer Rhodes
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Hirsh, S. Agent, University of Maryland Extension, Maryland, 21853
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Sater, H. Agent, University of Maryland Extension, Maryland, 21801
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Joseph, D. Agent, University of Maryland Extension, Maryland, 21620
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Dill, S. Principal Agent, University of Maryland Extension, Maryland, 21601
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Rhodes, J. Principal Agent, University of Maryland Extension, Maryland, 21617