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Seasonal And Rotational Influences On Corn Nitrogen Requirements, John E. Sawyer, Daniel W. Barker 2017 Iowa State University

Seasonal And Rotational Influences On Corn Nitrogen Requirements, John E. Sawyer, Daniel W. Barker

John E. Sawyer

This project is designed to study nitrogen (N) fertilization needs in continuous corn (C-C) and corn rotated with soybeans (C-S) as influenced by location and climate. Multiple rates of N fertilizer are spring applied, with the intent to measure yield response to N fertilization within each rotation on a yearly basis for multiple years at multiple sites across Iowa. This will help determine N requirements for each rotation practice, differences that exist between the two rotations, and responses to applied N across different soils and climatic conditions. It will also allow for the evaluation of tools used to adjust N ...


Seasonal And Rotational Influences On Corn Nitrogen Requirements, John E. Sawyer, Daniel W. Barker 2017 Iowa State University

Seasonal And Rotational Influences On Corn Nitrogen Requirements, John E. Sawyer, Daniel W. Barker

John E. Sawyer

This project was designed to study the N fertilization needs in continuous corn (CC) and corn rotated with soybean (SC) as influenced by location and climate. Multiple rates of fertilizer N are spring applied, with the intent to measure yield response to N within each rotation on a yearly basis for multiple years at multiple sites across Iowa. This will allow the determination of N requirements for each rotation, differences that exist between the two rotations, responses to applied N across different soils and climatic conditions, and evaluation of tools used to adjust N application.


Seasonal And Rotational Influences On Corn Nitrogen Requirements, John E. Sawyer, Daniel W. Barker 2017 Iowa State University

Seasonal And Rotational Influences On Corn Nitrogen Requirements, John E. Sawyer, Daniel W. Barker

John E. Sawyer

This project was designed to study the N fertilization needs in continuous corn (CC) and corn rotated with soybean (SC) as influenced by location and climate. Multiple rates of fertilizer N are spring applied, with the intent to measure yield response to N within each rotation on a yearly basis for multiple years at multiple sites across Iowa. This will allow the determination of N requirements for each rotation, differences that exist between the two rotations, responses to applied N across different soils and climatic conditions, and evaluation of tools used to adjust N application.


Seasonal And Rotational Influences On Corn Nitrogen Requirements, John E. Sawyer, Daniel W. Barker 2017 Iowa State University

Seasonal And Rotational Influences On Corn Nitrogen Requirements, John E. Sawyer, Daniel W. Barker

John E. Sawyer

This project was designed to study the nitrogen (N) fertilization needs in continuous corn (C-C) and corn rotated with soybean (C-S) as influenced by location and climate. Multiple rates of fertilizer N were spring applied, with the intent to measure yield response to N within each rotation on a yearly basis for multiple years at multiple sites across Iowa. This will allow the determination of N requirements for each rotation practice, differences that exist between the two rotations, responses to N applied across different soils and climatic conditions, and evaluation of tools used to adjust N application.


Optimizing Nitrogen Fertilizer Application In Corn Using Green Technology, Daniel W. Barker, John E. Sawyer 2017 Iowa State University

Optimizing Nitrogen Fertilizer Application In Corn Using Green Technology, Daniel W. Barker, John E. Sawyer

John E. Sawyer

The utilization of active canopy sensors in corn (Zea Mays L.) for in-season N fertilizer management has the potential to maintain optimal production and conserve fertilizer N resources. Canopy sensors can be considered a green technology in production agriculture by attempting equitable land stewardship and providing an economically viable N management practice. Robust and accurate algorithms to determine an appropriate N application rate based on canopy sensing is needed in order to effectively utilize sensors in Iowa production fields. The objective of this study was to develop N rate algorithms using active canopy sensors which can prescribe in-season N application ...


Phosphorus And Potassium In Silage Harvest Of Drought-Damaged Corn, John E. Sawyer, Antonio P. Mallarino 2017 Iowa State University

Phosphorus And Potassium In Silage Harvest Of Drought-Damaged Corn, John E. Sawyer, Antonio P. Mallarino

John E. Sawyer

The dry conditions this summer are resulting in quite variable corn growth and production potential. Some livestock producers are beginning harvest of corn damaged by drought conditions for silage. Corn silage harvest results in more phosphorus (P) and potassium (K) removal than grain alone because almost the entire plant is harvested. The increased amount removed with silage differs for P and K because the relative amount of P and K is different in corn vegetative parts than in grain. For P there can be approximately four times greater amount of P per ton of dry matter in grain than vegetative ...


Phosphorus, Potassium And Ph Management Issues Following Drought-Damaged Crops, Antonio P. Mallarino, John E. Sawyer 2017 Iowa State University

Phosphorus, Potassium And Ph Management Issues Following Drought-Damaged Crops, Antonio P. Mallarino, John E. Sawyer

John E. Sawyer

Exceptionally dry conditions this summer will result in low crop yield in much of Iowa, and weather forecasts call for normal or below normal rainfall through the fall. These dry conditions and low yields will significantly reduce phosphorus (P) and potassium (K) removal with crop harvest, and may also affect soil test P, K and pH results, complicating test interpretations.


Pay Attention To Management Needs Of Fertilizer Products, John E. Sawyer 2017 Iowa State University

Pay Attention To Management Needs Of Fertilizer Products, John E. Sawyer

John E. Sawyer

With concerns this spring about nitrogen (N) fertilizer availability and pricing, perhaps you are considering an N product you haven't used before. What management considerations should you pay attention to? When properly managed, all N fertilizers can be effective for supplying crop N needs.


Phosphorus - Why The Concern About Water Quality?, John Creswell, Antonio P. Mallarino, Gerald A. Miller, John E. Sawyer, Michael J. Tidman 2017 Iowa State University

Phosphorus - Why The Concern About Water Quality?, John Creswell, Antonio P. Mallarino, Gerald A. Miller, John E. Sawyer, Michael J. Tidman

John E. Sawyer

This article concludes a series that provides producers with information to help with on-farm management of phosphorus (P) and in understanding the complex economic and environmental issues involved in P management. This article discusses potential regulatory action and offers options to help producers move toward compliance. Iowa has many water quality challenges. It may be helpful to take a step back from the science of water quality and review the politics of water quality. What are some potential regulations and what can producers do to be in compliance?


On-Farm Sulfur Fertilization Of Corn And Soybean Trials, Jim Fawcett, Jim Rogers, Lance Miller, John Sawyer 2017 Iowa State University

On-Farm Sulfur Fertilization Of Corn And Soybean Trials, Jim Fawcett, Jim Rogers, Lance Miller, John Sawyer

John E. Sawyer

In the past several years, sulfur (S) deficiency has been showing up more frequently in Iowa fields than what had been seen in the past. Yield response has especially occurred in corn and alfalfa fields in northeast Iowa. Increase in S response may be partially due to less S in rainfall from more stringent air pollution regulations, less S fertilizer applications, higher crop yields, and less widespread use of manure. S applications can offer yield increases where S deficiencies are present. The objective of these trials was to evaluate grain yield response in corn and soybean to S.


Nitrogen Loss: How Does It Happen?, John E. Sawyer 2017 Iowa State University

Nitrogen Loss: How Does It Happen?, John E. Sawyer

John E. Sawyer

For the period April 1 through May 6, 2007, much of Iowa received more than 5 inches of rainfall (May 6, 2007 AWIS Inc. report). The Northwest, North-Central, and East-Central districts averaged slightly less than 5 inches, and the West-Central and Southwest districts more than 9 inches. With the large rainfall and flooding conditions, many producers are wondering about nitrogen (N) losses. While this period certainly has an influence on N in the soil, excessively wet conditions later in the spring are especially important for N losses. Early to mid-June will be a critical period to assess crop growth and ...


Nitrogen Losses In 2001, John E. Sawyer 2017 Iowa State University

Nitrogen Losses In 2001, John E. Sawyer

John E. Sawyer

It has been another moist spring in Iowa. Some locations, like areas in southeastern Iowa, have experienced excessively wet soils several times this spring. Loss of applied nitrogen (N) is once again an issue. But yellow corn does not always equate to N deficiency; plant response to cold and wet conditions (slowed root activity and growth) also impacts foliage color. When corn is small the impact of cold, wet weather, not lack of N, is probably the cause of discoloration because the amount of N taken up by corn to the V6 stage is small (20 lb N/acre or ...


Nutrient Removal When Harvesting Corn Stover, John E. Sawyer, Antonio P. Mallarino 2017 Iowa State University

Nutrient Removal When Harvesting Corn Stover, John E. Sawyer, Antonio P. Mallarino

John E. Sawyer

Increasing demand to use corn plant biomass for producing energy and other products has spurred interest in harvesting corn stover and specific plant components in addition to grain. The technology and infrastructure needed for effective use of total corn plant biomass in energy production is currently being investigated and its implementation at a large scale in the near future is a real possibility. Harvesting more biomass means increased carbon (C) and other nutrient removal from fields. What is the nutrient removal when different corn plant components are harvested?


Nitrogen Loss—Spring 2013, John E. Sawyer 2017 Iowa State University

Nitrogen Loss—Spring 2013, John E. Sawyer

John E. Sawyer

Dry soils across Iowa from deficit precipitation following the drought in 2012 have changed to excess wetness this spring. Unfortunately, precipitation to replenish subsoil moisture has been much more than needed. As I wrote in an ICM News article earlier this spring, one downside to the excess precipitation has been movement of carryover nitrate deeper into the profile and to tile lines, resulting in high nitrate-N concentrations in surface waters. This means there is less nitrate-N carryover to be utilized by 2013 crops, although as noted in the previous article, not all of the carryover N moved below the three-foot ...


Nitrogen Loss?, John E. Sawyer 2017 Iowa State University

Nitrogen Loss?, John E. Sawyer

John E. Sawyer

Really, it just had to rain large amounts in December. Seems we can’t get any relief from worrying about excess rain and impacts on nitrogen (N). The questions have already begun – what about fall 2015 fertilizer and manure N applications? It is quite hard to make an estimate of losses for such an extreme event and time of the year. Following are factors to consider that will affect loss potential, including if N was applied and if so what fertilizer product or manure source.


Nitrogen Loss – How Does It Happen?, John E. Sawyer 2017 Iowa State University

Nitrogen Loss – How Does It Happen?, John E. Sawyer

John E. Sawyer

Much of Iowa is experiencing excessively wet conditions this spring. With the continued large rainfalls and flooding conditions, nitrogen (N) loss is an issue. While the wet period early this spring had an influence on N in the soil, excessively wet conditions now are especially critical for N losses due to warm soils and considerable conversion of applied fertilizer and manure N to nitrate.


Nitrogen Fertilizer Management Options, John E. Sawyer 2017 Iowa State University

Nitrogen Fertilizer Management Options, John E. Sawyer

John E. Sawyer

Carefully weigh the optimum timing and placement of each pound of N used this year. All N fertilizers are effective for supplying crop N needs when properly managed. On soils with large potential for N loss (leaching or denitrification), application close to crop uptake is important to minimize losses. Avoid early applications, especially for products containing the nitrate form of N. Be mindful of the unique properties and management needs of each material. Don't get in a rush and waste valuable N just to get the job done.


Collaborative Research: The Interplay Between Fluctuating Selection On Symbionts And Life Cycle Evolution In Sap-Sucking Insects, Carol von Dohlen 2017 Utah State University

Collaborative Research: The Interplay Between Fluctuating Selection On Symbionts And Life Cycle Evolution In Sap-Sucking Insects, Carol Von Dohlen

Funded Research and Data

No abstract provided.


Santa Rosa (Cota), Diseños 474, Glo 370, Santa Rosa (Cota), And Associated Historical Documents, 2017 California State University, Monterey Bay

Santa Rosa (Cota), Diseños 474, Glo 370, Santa Rosa (Cota), And Associated Historical Documents

Santa Barbara County

Diseños - Hand-drawn Spanish-Mexican map demonstrating the physical boundaries of land granted to Mexican citizens by the Spanish or Mexican.

Expediente – Hand-written Spanish-Mexican land grant document issued to Mexican citizens in Alta California for land in Alta-California.

Work Progress Administration Abstract (WPA Abstract) – A summary document prepared in 1938 under the Work Progress Administration program detailing the history of a rancho beginning with the Spanish-American land through the U.S. patenting process.

Hoffman Notes -- Summary of information concerning claims made for the Rancho lands from the Appendix containing the Table of Land Claims in the Reports of Land Cases by Ogden ...


Early Emergence And Seasonality Of The Red-Bellied Snake (Storeria Occipitomaculata) Along The Platte River In South-Central Nebraska, Usa, Simon P. Tye, Keith Geluso, Mary J. Harner 2017 University of Nebraska, Kearney

Early Emergence And Seasonality Of The Red-Bellied Snake (Storeria Occipitomaculata) Along The Platte River In South-Central Nebraska, Usa, Simon P. Tye, Keith Geluso, Mary J. Harner

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

The Red-bellied Snake (Storeria occipitomaculata) primarily inhabits moist woodlands of eastern North America, with two disjunct populations occurring in the Great Plains, one of which is in south-central Nebraska. This species is listed as at-risk in Nebraska, in part, due to being uncommon with limited information available about the ecology and natural history of this isolated population. We amassed 48 observations of Red-bellied Snakes in Nebraska from museum specimens and published accounts, including our observations and others reported to us published herein. The previous earliest documented date of spring emergence was 6 April from a specimen collected in 1999. On ...


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