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Modeling Long-Term Corn Yield Response To Nitrogen Rate And Crop Rotation, Laila A. Puntel, John E. Sawyer, Daniel Barker, Ranae N. Dietzel, Hanna Poffenbarger, Michael J. Castellano, Kenneth J. Moore, Peter Thorburn, Sotirios Archontoulis Nov 2016

Modeling Long-Term Corn Yield Response To Nitrogen Rate And Crop Rotation, Laila A. Puntel, John E. Sawyer, Daniel Barker, Ranae N. Dietzel, Hanna Poffenbarger, Michael J. Castellano, Kenneth J. Moore, Peter Thorburn, Sotirios Archontoulis

John E. Sawyer

Improved prediction of optimal N fertilizer rates for corn (Zea mays L.) can reduce N losses and increase profits. We tested the ability of the Agricultural Production Systems sIMulator (APSIM) to simulate corn and soybean (Glycine max L.) yields, the economic optimum N rate (EONR) using a 16-year field-experiment dataset from central Iowa, USA that included two crop sequences (continuous corn and soybean-corn) and five N fertilizer rates (0, 67, 134, 201, and 268 kg N ha-1) applied to corn. Our objectives were to: (a) quantify model prediction accuracy before and after calibration, and report calibration steps; (b) compare crop …


Modeling Long-Term Corn Yield Response To Nitrogen Rate And Crop Rotation, Laila A. Puntel, John E. Sawyer, Daniel W. Barker, Ranae Dietzel, Hanna Poffenbarger, Michael J. Castellano, Kenneth J. Moore, Peter J. Thorburn, Sotirios V. Archontoulis Nov 2016

Modeling Long-Term Corn Yield Response To Nitrogen Rate And Crop Rotation, Laila A. Puntel, John E. Sawyer, Daniel W. Barker, Ranae Dietzel, Hanna Poffenbarger, Michael J. Castellano, Kenneth J. Moore, Peter J. Thorburn, Sotirios V. Archontoulis

Department of Agronomy and Horticulture: Faculty Publications

Improved prediction of optimal N fertilizer rates for corn (Zea mays L.) can reduce N losses and increase profits. We tested the ability of the Agricultural Production Systems sIMulator (APSIM) to simulate corn and soybean (Glycine max L.) yields, the economic optimum N rate (EONR) using a 16-year field-experiment dataset from central Iowa, USA that included two crop sequences (continuous corn and soybean-corn) and five N fertilizer rates (0, 67, 134, 201, and 268 kg N ha-1) applied to corn. Our objectives were to: (a) quantify model prediction accuracy before and after calibration, and report calibration steps; (b) …


More Crop Per Drop: Benchmarking On-Farm Irrigation Water Use For Crop Production., Katherine Elizabeth Boone Gibson Jul 2016

More Crop Per Drop: Benchmarking On-Farm Irrigation Water Use For Crop Production., Katherine Elizabeth Boone Gibson

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Efficient use of irrigation is essential to meet food production needs of growing global populations while ensuring long-term sustainability of freshwater resources. However, lack of on-farm irrigation data constrains understanding of irrigation variation and no framework exists to benchmark irrigation use using actual irrigation data. The following work investigates variation in irrigation using a database of ca. 1400 maize and soybean fields over 9 years in Nebraska and presents a framework to benchmark irrigation use using a separate database of ca. 1000 maize and soybean fields in Nebraska as proof of concept. “State-of-the-art” crop models estimated yield potential and irrigation …


From Milpas To The Market: A Study On The Use Of Metal Silos For Safer And Better Storage Of Guatemalan Maize, José Rodrigo Mendoza Jul 2016

From Milpas To The Market: A Study On The Use Of Metal Silos For Safer And Better Storage Of Guatemalan Maize, José Rodrigo Mendoza

Department of Food Science and Technology: Dissertations, Theses, and Student Research

This project aimed to implement the use of metal silos to improve quality and safety of maize consumed by inhabitants of the highlands of Guatemala. This manuscript includes a literature review of the maize production chain in Guatemala, a survey about agricultural practices used in the region of study, as well as a characterization of the analyzed maize regarding its mycoflora, nutritional composition, and insect infestation. To better understand the current situation regarding agricultural practices and maize consumption, a survey was carried out. Sample consisted of 280 families representing 14 rural communities distributed in the townships of Todos Santos and …


Irrigated And Rainfed Crops Zea Mays L. (Maize) And Glycine Max (Soybean) Acting As A Source Or Sink For Atmospheric Warming At Mead, Nebraska, Jane A. Okalebo Dr., Kenneth G. Hubbard, Andy Suyker May 2016

Irrigated And Rainfed Crops Zea Mays L. (Maize) And Glycine Max (Soybean) Acting As A Source Or Sink For Atmospheric Warming At Mead, Nebraska, Jane A. Okalebo Dr., Kenneth G. Hubbard, Andy Suyker

Conference on Applied Statistics in Agriculture

Land Use and Land Cover Change (LULCC) influence the climate at a global and local scale. Using long term microclimate data (2002-2009, 2011-2012) from the Carbon Sequestration Project (CSP), Mead, NE, this study examines how crop selection and water management can mitigate heat in the atmosphere. Mitigation of global warming is dependent on the management of crop lands, and the amount and timing of rainfall during the growing season. Rainfed crops were found to heat the passing air. The irrigated maize crop was able to mitigate 20 to 62% of the sensible heat (H) compared to the rainfed maize counterpart, …


The Politics Of Maize In Zambia: Who Holds The Keys To Change The Status Quo?, Antony Chapoto, Olipa Zulu-Mbata, Barak D. Hoffman, Chance Kabaghe, Nicholas J. Sitko, Auckland Kuteya, Ballard Zulu Jan 2016

The Politics Of Maize In Zambia: Who Holds The Keys To Change The Status Quo?, Antony Chapoto, Olipa Zulu-Mbata, Barak D. Hoffman, Chance Kabaghe, Nicholas J. Sitko, Auckland Kuteya, Ballard Zulu

Zambia Social Science Journal

As both the national staple food and primary smallholder crop, maize occupies a central position in Zambia’s agricultural political economy. Despite the government’s large subsidies, maize productivity levels remain way below global averages, maize commercialisation in the smallholder sector remains highly concentrated, maize meal prices are highly volatile, and rural poverty remains high. This study uses a political economy framework to better understand the policy-making process, power structures and dynamics involved in the maize sector in order to get a better understanding of who holds the keys to change, and how to influence agricultural policy changes. Net-Map procedure was used …


Improving Nitrogen-Use And Radiation-Use Efficiencies Of C4 Summer Cerealsby Split Nitrogen Applications Under An Irrigated Arid Environment, Shakeel Ahmad, Hakoomat Ali, Umair Farooq, Shahzad Usman Khan, Atique-Ur Rehman, Naeem Sarwar, Ahmad Naeem Shahzad, Hülya Doğan, Shabbir Hussain, Muhammad Tauseef Sultan, Abdul Waheed, Muhammad Zia Ul Haq, Khadim Hussain, Muhammad Azam Khan Jan 2016

Improving Nitrogen-Use And Radiation-Use Efficiencies Of C4 Summer Cerealsby Split Nitrogen Applications Under An Irrigated Arid Environment, Shakeel Ahmad, Hakoomat Ali, Umair Farooq, Shahzad Usman Khan, Atique-Ur Rehman, Naeem Sarwar, Ahmad Naeem Shahzad, Hülya Doğan, Shabbir Hussain, Muhammad Tauseef Sultan, Abdul Waheed, Muhammad Zia Ul Haq, Khadim Hussain, Muhammad Azam Khan

Turkish Journal of Agriculture and Forestry

Increasing resource-use efficiency is of prime importance in sustainable agriculture. A field study was carried out to improve nitrogen-use efficiency (NUE) and radiation-use efficiency (RUE) of three C4 summer cereals, i.e. Maize, millet, and sorghum, under an irrigated arid environment. The results showed that among various cultivars of cereals, cultivars Pearl (maize), 18 BY (millet), and Jumbo (sorghum) produced the highest aboveground total dry matters and grain yields. The highest NUE and RUE were obtained by splitting the nitrogen dose 3 times, i.e. At sowing and at first and second irrigation. The NUE for maize, millet, and sorghum varied from …


Regional Variations Of Optimal Sowing Dates Of Maize For The Southwestern U.S., Boksoon Myoung, Seung Hee Kim, Jinwon Kim, Menas Kafatos Jan 2016

Regional Variations Of Optimal Sowing Dates Of Maize For The Southwestern U.S., Boksoon Myoung, Seung Hee Kim, Jinwon Kim, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Sowing date (SD) is sensitive to regional climate characteristics; thus, it is critical to systematically examine the effects of SD on crop yields for various temperature regimes. We performed a sensitivity study of SD for maize in the southwestern U.S. using the regionally extended version of the Agricultural Production Systems sIMulator (APSIM) model. The model was run utilizing North American Regional Reanalysis at a 32 km resolution from 1991 to 2011, with an irrigation threshold at 95% of the soil water-holding capacity. Two types of SD optimizations maximizing yield potential (Yp), varying spatially or interannually, revealed that the optimal SD …


Irrigated Zea Mays Response To Nitrogen And High Plant Population Density In Narrow Rows, Julie Baniszewski Jan 2016

Irrigated Zea Mays Response To Nitrogen And High Plant Population Density In Narrow Rows, Julie Baniszewski

Theses and Dissertations--Plant and Soil Sciences

Modern genetics have improved maize hybrids to better tolerate stress, use nutrients more efficiently and potentially yield higher. Management practices, such as narrow row technology and high plant population density (PPD) may further improve yields in modern maize under irrigated, non-limiting conditions. High PPD (74, 99, 124, 148 K seeds ha-1) were tested in narrow rows with up to four nitrogen (N) rates in three locations over two years in Kentucky with a modern maize hybrid in irrigated, non-limiting conditions. Results indicate that optimal seeding rates were 99,000 to 124,000 seeds ha-1, providing maximum yield and …


Simulating Long-Term Impacts Of Cover Crops And Climate Change On Crop Production And Environmental Outcomes In The Midwestern United States, Andrea D. Basche, Sotririos V. Archontoulis, Thomas C. Kaspar, Dan B. Jaynes, Timothy B. Parkin, Fernando E. Miguez Jan 2016

Simulating Long-Term Impacts Of Cover Crops And Climate Change On Crop Production And Environmental Outcomes In The Midwestern United States, Andrea D. Basche, Sotririos V. Archontoulis, Thomas C. Kaspar, Dan B. Jaynes, Timothy B. Parkin, Fernando E. Miguez

Department of Agronomy and Horticulture: Faculty Publications

It is critical to evaluate conservation practices that protect soil and water resources from climate change in the Midwestern United States, a region that produces one-quarter of the world’s soybeans and one-third of the world’s maize. An over-winter cover crop in a maize–soybean rotation offers multiple potential benefits that can reduce the impacts of higher temperatures and more variable rainfall; some of the anticipated changes for the Midwest. In this experiment we used the Agricultural Production Systems sIMulator (APSIM) to understand how winter rye cover crops impact crop production and environmental outcomes, given future climate change. We first tested APSIM …


Proteomic Profiling Of Maize Opaque Endosperm Mutants Reveals Selective Accumulation Of Lysine-Enriched Proteins, Kyla J. Morton, Shangang Jia, Chi Zhang, David R. Holding Jan 2016

Proteomic Profiling Of Maize Opaque Endosperm Mutants Reveals Selective Accumulation Of Lysine-Enriched Proteins, Kyla J. Morton, Shangang Jia, Chi Zhang, David R. Holding

Department of Agronomy and Horticulture: Faculty Publications

Reduced prolamin (zein) accumulation and defective endoplasmic reticulum (ER) body formation occurs in maize opaque endosperm mutants opaque2 (o2), floury2 (fl2), defective endosperm*B30 (DeB30), and Mucronate (Mc), whereas other opaque mutants such as opaque1 (o1) and floury1 (fl1) are normal in these regards. This suggests that other factors contribute to kernel texture. A liquid chromatography approach coupled with tandem mass spectrometry (LC-MS/MS) proteomics was used to compare non-zein proteins of nearly isogenic opaque endosperm mutants. In total, 2762 proteins were identified that were enriched for biological processes such …


Proteomic Profiling Of Maize Opaque Endosperm Mutants Reveals Selective Accumulation Of Lysine-Enriched Proteins, Kyla J. Morton, Shangang Jia, Chi Zhang, David R. Holding Jan 2016

Proteomic Profiling Of Maize Opaque Endosperm Mutants Reveals Selective Accumulation Of Lysine-Enriched Proteins, Kyla J. Morton, Shangang Jia, Chi Zhang, David R. Holding

Department of Agronomy and Horticulture: Faculty Publications

Reduced prolamin (zein) accumulation and defective endoplasmic reticulum (ER) body formation occurs in maize opaque endosperm mutants opaque2 (o2), floury2 (fl2), defective endosperm*B30 (DeB30), and Mucronate (Mc), whereas other opaque mutants such as opaque1 (o1) and floury1 (fl1) are normal in these regards. This suggests that other factors contribute to kernel texture. A liquid chromatography approach coupled with tandem mass spectrometry (LC-MS/MS) proteomics was used to compare non-zein proteins of nearly isogenic opaque endosperm mutants. In total, 2762 proteins were identified that were enriched for biological processes such …


Impact Of Derived Global Weather Data On Simulated Crop Yields, Justin Van Wart, Patricio Grassini, Kenneth Cassman Jan 2016

Impact Of Derived Global Weather Data On Simulated Crop Yields, Justin Van Wart, Patricio Grassini, Kenneth Cassman

Department of Agronomy and Horticulture: Faculty Publications

Crop simulation models can be used to estimate impact of current and future climates on crop yields and food security, but require long-term historical daily weather data to obtain robust simulations. In many regions where crops are grown, daily weather data are not available. Alternatively, gridded weather databases (GWD) with complete terrestrial coverage are available, typically derived from: (i) global circulation computer models; (ii) interpolated weather station data; or (iii) remotely sensed surface data from satellites. The present study’s objective is to evaluate capacity of GWDs to simulate crop yield potential (Yp) or water-limited yield potential (Yw), which can serve …