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7. No-till spring cereal cropping systems reduce wind erosion susceptibility in the wheat/fallow region of the Pacific Northwest

Author

Thorne, Mark E., Young, Frank L., Pan, William L., Bafus, Rhonda, and Alldredge, J. Richard

Subjects
Soil erosion -- Research, Environmental issues, Research
Abstract

********** Wind-borne soil erosion from cropland in the Columbia Basin and Plateau of eastern Washington and Oregon is a major concern for air quality in the region (Saxton 1995). Airborne [...]

Published
2003

8. Toward a Better Understanding of Genotype × Environment × Management Interactions—A Global Wheat Initiative Agronomic Research Strategy

Author

Beres, Brian L., primary, Hatfield, Jerry L., additional, Kirkegaard, John A., additional, Eigenbrode, Sanford D., additional, Pan, William L., additional, Lollato, Romulo P., additional, Hunt, James R., additional, Strydhorst, Sheri, additional, Porker, Kenton, additional, Lyon, Drew, additional, Ransom, Joel, additional, and Wiersma, Jochum, additional

Published
2020
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13. Barley semidwarf and standard isotype yield and malting quality response to nitrogen

Author

Nedel, Jorge L., Ullrich, Steven E., Clancy, Janet A., and Pan, William L.

Subjects
Barley -- Genetic aspects, Dwarf plants -- Genetic aspects, Crops and nitrogen -- Genetic aspects, Agricultural industry, Business
Abstract

Introduction of certain semidwarf genes into wheat (Triticum spp.) has improved N-use efficiency, particularly at high N supply. This study was conducted to determine whether yield and grain quality differ between standard height (STD) and mutant semidwarf (SD) malting barley (Hordeum vulgare L.) isotypes with varying levels of N supply. Isotype pairs (|Morex', |Hazen', |Norbert', and |Andre') and check cultivars (Steptoe, Klages) were grown vath 30, 60, 90, and 120 kg N [ha.sup.-1] in 1987 and 1989. Yield, grain characteristics, and malting quality parameters were evaluated. The STD isotypes had higher yield (6781 vs. 5642 and 5202 vs. 4504 kg [ha.sup.-1] in 1987 and 1989, respectively) and generally higher values for yield components and harvest index, as well as better grain quality than their respective SD isotypes; however, two-row SD isotypes had better malting quality than their STD isotypes. The generally superior performance of STD isotypes in part may be due to the SD isotypes being raw induced mutants that had not been improved by crossing. Malting quality parameters, such as total malt protein and malt extract, were affected negatively by N >60 kg [ha.sup.-1], when the preceding crop was pea (Pisum sativum L.; high N); however, for yield and some malt quality parameters such as diastatic power, all genotypes responded significantly and positively to N fertilization when the preceding crop was barley (low N). In general, the response to N was similar for both barley types. As SD malting barley cultivars are developed to control lodging, they may not utilize more N or yield more than STD types.

Published
1993

20. Carbon and Water Budgets in Multiple Wheat-Based Cropping Systems in the Inland Pacific Northwest US: Comparison of CropSyst Simulations with Eddy Covariance Measurements

Author

Chi, Jinshu, Maureira, Fidel, Waldo, Sarah, Pressley, Shelley N., Stöckle, Claudio O., O'Keeffe, Patrick T., Pan, William L., Brooks, Erin S., Huggins, Dave R., Lamb, Brian K., Chi, Jinshu, Maureira, Fidel, Waldo, Sarah, Pressley, Shelley N., Stöckle, Claudio O., O'Keeffe, Patrick T., Pan, William L., Brooks, Erin S., Huggins, Dave R., and Lamb, Brian K.

Abstract

Accurate carbon and water flux simulations for croplands are greatly dependent on high quality representation of management practices and meteorological conditions, which are key drivers of the surface-atmosphere exchange processes. Fourteen site-years of carbon and water fluxes were simulated using the CropSyst model over four agricultural sites in the inland Pacific Northwest (iPNW) US from October 1, 2011 to September 30, 2015. Model performance for field-scale net ecosystem exchange of CO2 (NEE) and evapotranspiration (ET) was evaluated by comparing simulations with long-term eddy covariance measurements. The model captured the temporal variations of NEE and ET reasonably well with an overall r of 0.78 and 0.80, and a low RMSE of 1.82 g C m−2 d−1 and 0.84 mm d−1 for NEE and ET, respectively. The model slightly underestimated NEE and ET by 0.51 g C m−2 d−1 and 0.09 mm d−1, respectively. ET simulations showed better agreement with eddy covariance measurements than NEE. The model performed much better for the sites with detailed initial conditions (e.g., SOC content) and management practice information (e.g., tillage type). The CropSyst results showed that the winter wheat fields could be annual net carbon sinks or close to neutral with the net ecosystem carbon balance (NECB) ranging from 92 to −17 g C m−2, while the spring crop fields were net carbon sources or neutral with an annual NECB of −327 to −3 g C m−2. Simulations for the paired tillage sites showed that the no-till site resulted in lower CO2 emissions for the crop rotations of winter wheat-spring garbanzo, but had higher carbon loss into the atmosphere for spring canola compared to the conventional tillage site. Water budgets did not differ significantly between the two tillage systems. Winter wheat in the high-rainfall area had higher crop yields and water use efficiency but emitted larger amoun

Published
2017

21. Effects of Climatic Conditions and Management Practices on Agricultural Carbon and Water Budgets in the Inland Pacific Northwest USA

Author

Chi, Jinshu, Waldo, Sarah, Pressley, Shelley N., Russell, Eric S., O'Keeffe, Patrick T., Pan, William L., Huggins, David R., Stöckle, Claudio O., Brooks, Erin S., Lamb, Brian K., Chi, Jinshu, Waldo, Sarah, Pressley, Shelley N., Russell, Eric S., O'Keeffe, Patrick T., Pan, William L., Huggins, David R., Stöckle, Claudio O., Brooks, Erin S., and Lamb, Brian K.

Abstract

Cropland is an important land cover influencing global carbon and water cycles. Variability of agricultural carbon and water fluxes depends on crop species, management practices, soil characteristics, and climatic conditions. In the context of climate change, it is critical to quantify the long-term effects of these environmental drivers and farming activities on carbon and water dynamics. Twenty site-years of carbon and water fluxes covering a large precipitation gradient and a variety of crop species and management practices were measured in the inland Pacific Northwest using the eddy covariance method. The rain-fed fields were net carbon sinks, while the irrigated site was close to carbon neutral during the winter wheat crop years. Sites growing spring crops were either carbon sinks, sources, or neutral, varying with crops, rainfall zones, and tillage practices. Fluxes were more sensitive to variability in precipitation than temperature: annual carbon and water fluxes increased with the increasing precipitation while only respiration increased with temperature in the high-rainfall area. Compared to a nearby rain-fed site, irrigation improved winter wheat production but resulted in large losses of carbon and water to the atmosphere. Compared to conventional tillage, no-till had significantly lower respiration but resulted in slightly lower yields and water use efficiency over 4 years. Under future climate change, it is expected that more carbon fixation by crops and evapotranspiration would occur in a warmer and wetter environment.

Published
2017

23. Integrating Historic Agronomic and Policy Lessons with New Technologies to Drive Farmer Decisions for Farm and Climate: The Case of Inland Pacific Northwestern U.S.

Author

Pan, William L., primary, Schillinger, William F., additional, Young, Frank L., additional, Kirby, Elizabeth M., additional, Yorgey, Georgine G., additional, Borrelli, Kristy A., additional, Brooks, Erin S., additional, McCracken, Vicki A., additional, Maaz, Tai M., additional, Machado, Stephen, additional, Madsen, Isaac J., additional, Johnson-Maynard, Jodi L., additional, Port, Lauren E., additional, Painter, Kate, additional, Huggins, David R., additional, Esser, Aaron D., additional, Collins, Harold P., additional, Stockle, Claudio O., additional, and Eigenbrode, Sanford D., additional

Published
2017
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26. Impact of Climate Change Adaptation Strategies on Winter Wheat and Cropping System Performance across Precipitation Gradients in the Inland Pacific Northwest, USA

Author

Maaz, Tai M., primary, Schillinger, William F., additional, Machado, Stephen, additional, Brooks, Erin, additional, Johnson-Maynard, Jodi L., additional, Young, Lauren E., additional, Young, Frank L., additional, Leslie, Ian, additional, Glover, Ayana, additional, Madsen, Isaac J., additional, Esser, Aaron, additional, Collins, Harold P., additional, and Pan, William L., additional

Published
2017
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27. Carbon and Water Budgets in Multiple Wheat-Based Cropping Systems in the Inland Pacific Northwest US: Comparison of CropSyst Simulations with Eddy Covariance Measurements

Author

Chi, Jinshu, primary, Maureira, Fidel, additional, Waldo, Sarah, additional, Pressley, Shelley N., additional, Stöckle, Claudio O., additional, O'Keeffe, Patrick T., additional, Pan, William L., additional, Brooks, Erin S., additional, Huggins, Dave R., additional, and Lamb, Brian K., additional

Published
2017
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28. N2O Emissions From Two Agroecosystems: High Spatial Variability and Long Pulses Observed Using Static Chambers and the Flux‐Gradient Technique.

Author

Waldo, Sarah, Russell, Eric S., Kostyanovsky, Kirill, Pressley, Shelley N., O'Keeffe, Patrick T., Huggins, David R., Stöckle, Claudio O., Pan, William L., and Lamb, Brian K.

Subjects
NITROGEN in soils, AGRICULTURAL ecology, NITROUS oxide, GREENHOUSE gases, NITROGEN fertilizers
Abstract

With the addition of nitrogen (N), agricultural soils are the main anthropogenic source of N2O, but high spatial and temporal variabilities make N2O emissions difficult to characterize at the field scale. This study used flux‐gradient measurements to continuously monitor N2O emissions at two agricultural fields under different management regimes in the inland Pacific Northwest of Washington State, USA. Automated 16‐chamber arrays were also deployed at each site; chamber monitoring results aided the interpretation of the flux gradient results. The cumulative emissions over the six‐month (1 April–30 September) monitoring period were 2.4 ± 0.7 and 2.1 ± 2 kg N2O‐N/ha at the no‐till and conventional till sites, respectively. At both sites, maximum N2O emissions occurred following the first rainfall event after N fertilization, and both sites had monthlong emission pulses. The no‐till site had a larger N2O emission factor than the Intergovernmental Panel on Climate Change Tier 1 emission factor of 1% of the N input, while the conventional‐till site's emission factor was close to 1% of the N input. However, these emission factors are likely conservative. We estimate that the global warming potential of the N2O emissions at these sites is larger than that of the no‐till conversion carbon uptake. We recommend the use of chambers to investigate spatiotemporal controls as a complementary method to micrometeorological monitoring, especially in systems with high variability. Continued monitoring coupled with the use of models is necessary to investigate how changing management and environmental conditions will affect N2O emissions. Plain Language Summary: Nitrous oxide (N2O) is a greenhouse gas and stratospheric ozone depleting substance that is emitted by soils. Agricultural soils tend to emit more N2O than natural soils due to the addition of nitrogen fertilizers. N2O emissions are not well understood on the scale of individual farms, as emissions are difficult to measure at this resolution because they are irregular over time and space. This variability is due to the dependence of N2O production and emission on soil properties, that is, moisture, nitrogen, and the microbiome. In this study we monitored N2O emissions from two agricultural fields under different tillage regimes using two complementary methods: the flux‐gradient technique and automated chambers. The flux‐gradient technique measures N2O emissions at the field scale, which is relevant to agronomic management. Using both techniques together improves confidence in our results, which give us information on total N2O emissions from these fields, as well as the relationships between N2O emissions and rainfall, temperature, and carbon dioxide respiration. Key Points: Total emissions from 1 April to 30 September 2015 were 2.4 ± 0.7 and 2.1 ± 0.2 kg N2O‐N/ha at the no‐ and conventional‐till sites, respectivelyN2O fluxes had similar responses to temperature and precipitation at both sitesHigh spatial variability at both sites (CVs > 140%) limited the ability of the chamber systems to characterize field‐scale N2O emissions [ABSTRACT FROM AUTHOR]

Published
2019
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31. N2O Emissions From Two Agroecosystems: High Spatial Variability and Long Pulses Observed Using Static Chambers and the Flux‐Gradient Technique

Author

Waldo, Sarah, Russell, Eric S., Kostyanovsky, Kirill, Pressley, Shelley N., O'Keeffe, Patrick T., Huggins, David R., Stöckle, Claudio O., Pan, William L., and Lamb, Brian K.

Abstract

With the addition of nitrogen (N), agricultural soils are the main anthropogenic source of N2O, but high spatial and temporal variabilities make N2O emissions difficult to characterize at the field scale. This study used flux‐gradient measurements to continuously monitor N2O emissions at two agricultural fields under different management regimes in the inland Pacific Northwest of Washington State, USA. Automated 16‐chamber arrays were also deployed at each site; chamber monitoring results aided the interpretation of the flux gradient results. The cumulative emissions over the six‐month (1 April–30 September) monitoring period were 2.4 ± 0.7 and 2.1 ± 2 kg N2O‐N/ha at the no‐till and conventional till sites, respectively. At both sites, maximum N2O emissions occurred following the first rainfall event after N fertilization, and both sites had monthlong emission pulses. The no‐till site had a larger N2O emission factor than the Intergovernmental Panel on Climate Change Tier 1 emission factor of 1% of the N input, while the conventional‐till site's emission factor was close to 1% of the N input. However, these emission factors are likely conservative. We estimate that the global warming potential of the N2O emissions at these sites is larger than that of the no‐till conversion carbon uptake. We recommend the use of chambers to investigate spatiotemporal controls as a complementary method to micrometeorological monitoring, especially in systems with high variability. Continued monitoring coupled with the use of models is necessary to investigate how changing management and environmental conditions will affect N2O emissions. Nitrous oxide (N2O) is a greenhouse gas and stratospheric ozone depleting substance that is emitted by soils. Agricultural soils tend to emit more N2O than natural soils due to the addition of nitrogen fertilizers. N2O emissions are not well understood on the scale of individual farms, as emissions are difficult to measure at this resolution because they are irregular over time and space. This variability is due to the dependence of N2O production and emission on soil properties, that is, moisture, nitrogen, and the microbiome. In this study we monitored N2O emissions from two agricultural fields under different tillage regimes using two complementary methods: the flux‐gradient technique and automated chambers. The flux‐gradient technique measures N2O emissions at the field scale, which is relevant to agronomic management. Using both techniques together improves confidence in our results, which give us information on total N2O emissions from these fields, as well as the relationships between N2O emissions and rainfall, temperature, and carbon dioxide respiration. Total emissions from 1 April to 30 September 2015 were 2.4 ± 0.7 and 2.1 ± 0.2 kg N2O‐N/ha at the no‐ and conventional‐till sites, respectivelyN2O fluxes had similar responses to temperature and precipitation at both sitesHigh spatial variability at both sites (CVs > 140%) limited the ability of the chamber systems to characterize field‐scale N2O emissions

Published
2019
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