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Dialing In the Most Corn-Profitable and Environmentally Responsible Nitrogen Rate
Dialing In the Most Corn-Profitable and Environmentally Responsible Nitrogen Rate
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20260202104843
- ISBN
- 9798293871797
- DDC
- 630
- 서명/저자
- Dialing In the Most Corn-Profitable and Environmentally Responsible Nitrogen Rate
- 발행사항
- [Sl] : University of Minnesota, 2025
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2025
- 형태사항
- 87 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 87-03, Section: B.
- 주기사항
- Advisor: Fernandez, Fabian G.
- 학위논문주기
- Thesis (Ph.D.)--University of Minnesota, 2025.
- 초록/해제
- 요약Efficient nitrogen (N) management is essential for optimizing corn (Zea mays L.) productivity while minimizing environmental N losses in subsurface-drained continuous corn (CC) systems. This three-year study (2021 - 2023) at the Southwest Research and Outreach Center (SWROC) in Lamberton, Minnesota evaluated agronomic responses and environmental N losses across five N rates (0 - 360 kg N ha-1 ) using N best management practices (N-BMPs) including timing (in-season split application), placement (incorporation with tillage of pre-plant fertilizer), and source [enhanced efficiency fertilizers: polymer coated urea (ESN) and urea treated with the urease inhibitor N-(n-Butyl) thiophosphoric triamide (NBPT)]. Measurements included grain yield, plant total N uptake (TNU), soil total inorganic N (TIN) at various depths within the top 90 cm, canopy sensing for N management, and N loss measurements of nitrate (NO3-N) leaching, ammonia (NH3-N) volatilization, and nitrous oxide (N2O-N) emissions. The mean economic optimum N rate (EONR) was 173 kg N ha-1 , with a coefficient of variation (CV) of 23%, corresponding to an optimum range of 133 to 213 kg N ha-1. Above this threshold, yield gains plateaued or declined while residual soil N, N2O-N emissions, and NO3-N leaching increased linearly, indicating declining N use efficiency (NUE) and increased environmental risk. At 25% above the mean EONR, total N loss was estimated at 24.6 kg N ha-1 , with NO3-N leaching accounting for 86% of the total, compared to only a 3% yield gain. This illustrates the disproportionate rise in environmental loss relative to agronomic benefit. Ammonia volatilization was most prominent in 2021 and influenced primarily by dry surface conditions rather than N rate. Nitrous oxide emissions peaked in 2022, because early-season rainfall events and waterlogging coincided with high surface N accumulation from prior dry conditions. Nitrate leaching dominated in 2023 due to frequent early-season precipitation and drainage. This sequence shows that timing and intensity of precipitation, not only total rainfall, critically shaped dominant N loss pathways. When one loss pathway increased, another often declined, revealing tradeoffs and demonstrating the interconnected nature of N loss mechanisms and the need for integrated management practices. Managing N inputs within a flexible EONR range provides a practical strategy to maintain yield and mitigate environmental losses across variable growing conditions. This study highlights the value of concurrently measuring multiple N loss pathways and supports season-specific adaptive strategies to reduce the environmental footprint of intensive CC production.
- 일반주제명
- Agriculture
- 일반주제명
- Environmental science
- 일반주제명
- Soil sciences
- 일반주제명
- Agronomy
- 일반주제명
- Agricultural chemistry
- 키워드
- Ammonia
- 키워드
- Corn
- 키워드
- Drainage
- 키워드
- Nitrate
- 키워드
- Nitrogen
- 키워드
- Nitrous oxide
- 기타저자
- University of Minnesota Water Resources Science
- 기본자료저록
- Dissertations Abstracts International. 87-03B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■006m o d
■007cr#unu||||||||
■020 ▼a9798293871797
■035 ▼a(MiAaPQ)AAI32173149
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a630
■1001 ▼aAanerud, Zachary James.
■24510▼aDialing In the Most Corn-Profitable and Environmentally Responsible Nitrogen Rate
■260 ▼a[Sl]▼bUniversity of Minnesota▼c2025
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2025
■300 ▼a87 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 87-03, Section: B.
■500 ▼aAdvisor: Fernandez, Fabian G.
■5021 ▼aThesis (Ph.D.)--University of Minnesota, 2025.
■520 ▼aEfficient nitrogen (N) management is essential for optimizing corn (Zea mays L.) productivity while minimizing environmental N losses in subsurface-drained continuous corn (CC) systems. This three-year study (2021 - 2023) at the Southwest Research and Outreach Center (SWROC) in Lamberton, Minnesota evaluated agronomic responses and environmental N losses across five N rates (0 - 360 kg N ha-1 ) using N best management practices (N-BMPs) including timing (in-season split application), placement (incorporation with tillage of pre-plant fertilizer), and source [enhanced efficiency fertilizers: polymer coated urea (ESN) and urea treated with the urease inhibitor N-(n-Butyl) thiophosphoric triamide (NBPT)]. Measurements included grain yield, plant total N uptake (TNU), soil total inorganic N (TIN) at various depths within the top 90 cm, canopy sensing for N management, and N loss measurements of nitrate (NO3-N) leaching, ammonia (NH3-N) volatilization, and nitrous oxide (N2O-N) emissions. The mean economic optimum N rate (EONR) was 173 kg N ha-1 , with a coefficient of variation (CV) of 23%, corresponding to an optimum range of 133 to 213 kg N ha-1. Above this threshold, yield gains plateaued or declined while residual soil N, N2O-N emissions, and NO3-N leaching increased linearly, indicating declining N use efficiency (NUE) and increased environmental risk. At 25% above the mean EONR, total N loss was estimated at 24.6 kg N ha-1 , with NO3-N leaching accounting for 86% of the total, compared to only a 3% yield gain. This illustrates the disproportionate rise in environmental loss relative to agronomic benefit. Ammonia volatilization was most prominent in 2021 and influenced primarily by dry surface conditions rather than N rate. Nitrous oxide emissions peaked in 2022, because early-season rainfall events and waterlogging coincided with high surface N accumulation from prior dry conditions. Nitrate leaching dominated in 2023 due to frequent early-season precipitation and drainage. This sequence shows that timing and intensity of precipitation, not only total rainfall, critically shaped dominant N loss pathways. When one loss pathway increased, another often declined, revealing tradeoffs and demonstrating the interconnected nature of N loss mechanisms and the need for integrated management practices. Managing N inputs within a flexible EONR range provides a practical strategy to maintain yield and mitigate environmental losses across variable growing conditions. This study highlights the value of concurrently measuring multiple N loss pathways and supports season-specific adaptive strategies to reduce the environmental footprint of intensive CC production.
■590 ▼aSchool code: 0130.
■650 4▼aAgriculture
■650 4▼aEnvironmental science
■650 4▼aSoil sciences
■650 4▼aAgronomy
■650 4▼aAgricultural chemistry
■653 ▼aAmmonia
■653 ▼aCorn
■653 ▼aDrainage
■653 ▼aNitrate
■653 ▼aNitrogen
■653 ▼aNitrous oxide
■690 ▼a0473
■690 ▼a0768
■690 ▼a0481
■690 ▼a0749
■690 ▼a0285
■71020▼aUniversity of Minnesota▼bWater Resources Science.
■7730 ▼tDissertations Abstracts International▼g87-03B.
■790 ▼a0130
■791 ▼aPh.D.
■792 ▼a2025
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17359156▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
