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Articles 121 - 150 of 154
Full-Text Articles in Agronomy and Crop Sciences
Corn Nitrogen Rate Calculator Update, John E. Sawyer
Corn Nitrogen Rate Calculator Update, John E. Sawyer
John E. Sawyer
The Corn Nitrogen Rate Calculator is an online tool that allows determination of nitrogen (N) application rates for corn production and is helpful in determining the effect of fertilizer and corn price on needed rates. The method for calculating suggested N rates is based on a regional (Corn Belt) approach to N rate guidelines. Details on the approach are provided in the regional publicationConcepts and Rationale for Regional Nitrogen Rate Guidelines for Corn. This approach and the Corn Nitrogen Rate Calculator are now being used by seven states across the Corn Belt: Iowa, Illinois, Indiana, Michigan, Minnesota, Ohio and Wisconsin.
Corn Nitrogen Rate Calculator Update, John E. Sawyer
Corn Nitrogen Rate Calculator Update, John E. Sawyer
John E. Sawyer
The Corn Nitrogen Rate Calculator is an online tool that allows determination of nitrogen (N) application rates for corn production and is helpful in determining the effect of fertilizer and corn price on needed rates. The method for calculating suggested N rates is based on a regional (Corn Belt) approach to N rate guidelines. Details on the approach are provided in the regional publicationConcepts and Rationale for Regional Nitrogen Rate Guidelines for Corn. This approach and the Corn Nitrogen Rate Calculator are now being used by seven states across the Corn Belt: Iowa, Illinois, Indiana, Michigan, Minnesota, Ohio and Wisconsin.
Corn Nitrogen Rate Calculator Web Tool Update, John E. Sawyer
Corn Nitrogen Rate Calculator Web Tool Update, John E. Sawyer
John E. Sawyer
The Iowa N response trial database was updated this past week with 27 additional response trials from 2006 research: 18 trials with corn following soybean and nine trials with corn following corn. There are now 164 N response trials for corn following soybean and 77 trials for corn following corn. Being able to easily update the database with recent data is one of the many advantages to this dynamic database approach for corn N rate guidelines. Having new response trial data allows rapid updating with changing hybrid genetics, rotations, and climatic conditions.
Corn Nitrogen Rate Calculator Web Tool Updated, John E. Sawyer
Corn Nitrogen Rate Calculator Web Tool Updated, John E. Sawyer
John E. Sawyer
Last fall the Corn Nitrogen (N) Rate Calculator Web tool went online. It is a resource that aids N-rate decisions for corn production and is helpful in determining the effect of fertilizer price on application rates. The method for calculating suggested N rates is based on a regional (Corn Belt) approach to nitrogen-rate guidelines. Details on the approach are provided in the regional publication, Concepts and Rationale for Regional Nitrogen Rate Guidelines for Corn, PM 2015. Background information and interpretation of suggested N-rate guidelines were previously provided in an ICM newsletter article.
Corn Nitrogen Rate Calculator Update, John E. Sawyer
Corn Nitrogen Rate Calculator Update, John E. Sawyer
John E. Sawyer
The Iowa nitrogen (N) response database in the corn nitrogen rate calculatorwas recently updated, with response trials added from 2009 research. There are now 188 trials for corn following soybean and 89 trials for corn following corn. Being able to easily update the database with recent data is one of the many advantages to this dynamic database approach for corn N rate guidelines. Having new response trial data allows rapid updating with changing hybrid genetics, rotations and climatic conditions.
Corn Following Corn In 2008, Mahdi Al-Kaisi, Roger W. Elmore, Antonio P. Mallarino, Palle Pedersen, Alison E. Robertson, John E. Sawyer, Jon J. Tollefson
Corn Following Corn In 2008, Mahdi Al-Kaisi, Roger W. Elmore, Antonio P. Mallarino, Palle Pedersen, Alison E. Robertson, John E. Sawyer, Jon J. Tollefson
John E. Sawyer
Corn following corn is in rough shape in areas across Iowa. Many wonder what is happening. The crop’s condition in general is not normal for this time of year. For example, last Sunday the USDA rated this year’s Iowa corn crop as 54 percent in ‘Good’ to ‘Excellent’ condition and 15 percent is ‘Poor’ or ‘Very Poor.’ Last year 72 percent was rated ‘Good’ to ‘Excellent’ and 5 percent was in ‘Poor’ or ‘Very Poor’ condition during the same week. Average plant height as of Sunday was 24 inches compared to 40 inches at end of the same week last …
Compressed Spring Workload In 2014? What Are Nitrogen Application Options?, John E. Sawyer
Compressed Spring Workload In 2014? What Are Nitrogen Application Options?, John E. Sawyer
John E. Sawyer
It was a long winter, with conditions this spring suitable for field work perhaps being later than normal. Also, some areas of Iowa did not have the typical amount of fall anhydrous ammonia applied. Questions are already coming about options for nitrogen (N) fertilization this spring, and the usual question should time be taken to get N applied or plant corn and apply N later.
Checking Corn Nitrogen Status, John E. Sawyer
Checking Corn Nitrogen Status, John E. Sawyer
John E. Sawyer
While most of Iowa has not been excessively wet this spring, a few areas have been hit with heavy rains. The potential for nitrogen (N) losses are low, but some fields or field areas are more at risk. Generally, losses should be minimized because wet soils occurred early in the spring when temperatures were cool and much of the heavy rainfall ran off fields. Of course, losses could change if we receive excessive rainfall into June, as occurred last year. If you are wondering about available N for this year's corn crop, you can consider a few methods to check …
Applying Fertilizer And Lime To Crp Land, John E. Sawyer, Antonio P. Mallarino
Applying Fertilizer And Lime To Crp Land, John E. Sawyer, Antonio P. Mallarino
John E. Sawyer
Sample and test soil to determine how much fertilizer, manure, and lime to apply to meet crop needs when converting land in CRP to crop production. This publication is part of a series, “Conservation Reserve Program: Issues and Options series,” designed to help CRP contract holders assess the land-use options available to them when the contracts expire. The series began as a project of the Leopold Center based on research supported by the Center.
Applying Additional Nitrogen After Wet Conditions, John E. Sawyer
Applying Additional Nitrogen After Wet Conditions, John E. Sawyer
John E. Sawyer
When conventional application equipment can be moved through the field (i.e., the soils are dry enough and the corn is short enough), then injection of anhydrous ammonia or UAN solutions would top the list of best options. Next would come urea-ammonium nitrate solution (UAN) surface dribbled between corn rows, and then broadcast urea. Broadcast UAN solution should be avoided on corn larger than the V7 growth stage.
Carbon And Nitrogen Cycling With Corn Biomass Harvest, John E. Sawyer, Antonio P. Mallarino
Carbon And Nitrogen Cycling With Corn Biomass Harvest, 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. What is the effect on soil carbon (C) and nitrogen (N) with stover removal? While C is an essential plant nutrient, C fertilization is not practiced as C is supplied to crops via photosynthesis from carbon dioxide (CO2) in air. However, with current issues about greenhouse gases, increased awareness of the importance of soil C sequestration, and efforts to reduce soil erosion, concerns have focused on the impact of corn stover removal.
Assessing Nitrogen Losses, John E. Sawyer
Assessing Nitrogen Losses, John E. Sawyer
John E. Sawyer
Several methods can help estimate nitrogen (N) loss and supplement N need. They should be used as guides and for information regarding N application. Late spring soil nitrate test. Details about this test can be found in the Iowa State University publication PM 1714, Nitrogen Fertilizer Recommendations for Corn in Iowa. Soil condition should allow the collection ofgood samples from the entire one-foot depth.
Broadcast Postemergence Uan Solution, John E. Sawyer
Broadcast Postemergence Uan Solution, John E. Sawyer
John E. Sawyer
Broadcast application of urea-ammonium nitrate (UAN) solution to growing corn has the potential to cause phytotoxic symptoms of leaf burn, loss of leaves, and reduced early growth. Burn symptoms will be visible within 24 to 48 hours after application. Depending upon the severity of damage, reduced plant growth may be visible for several weeks after application. Research conducted in Minnesota indicated that when corn plants are at the V3 growth stage (vegetative leaf stage defined according to the uppermost leaf whose leaf collar is visible--in this case three leaf collars visible), phytotoxic effects were worse at nitrogen (N) rates above …
Care With Plant Nutrient Analysis, John E. Sawyer, Antonio P. Mallarino
Care With Plant Nutrient Analysis, John E. Sawyer, Antonio P. Mallarino
John E. Sawyer
This season, many climatic and soil factors are causing problems with corn and soybean growth. Sometimes plants also exhibit nutrient deficiency symptoms. A natural questions is whether the plants are actually nutrient deficient. If they are expressing deficiency symptoms, then yes they are. However, the reason may not be due to insufficient available nutrients in the soil, but rather poor uptake due to climatic or soil factors affecting growth. This was recently discussed in an ICM News article for potassium (K) in corn and soybean. If the symptoms are clearly present, then there really is no need for plant sampling …
Anhydrous Ammonia Application And Dry Soils, John E. Sawyer
Anhydrous Ammonia Application And Dry Soils, John E. Sawyer
John E. Sawyer
It is almost time that anhydrous ammonia (NH3) applications could begin (remember 50 F and cooling 4-inch soil temperature). However, many soils in Iowa are quite dry this fall. So, can anhydrous ammonia be applied to dry soil? Will it be held in dry soil?
Anhydrous Application And Dry Soils, John E. Sawyer
Anhydrous Application And Dry Soils, John E. Sawyer
John E. Sawyer
It was just last fall when soils were very dry in many areas of Iowa, and this fall they may be even drier. So, questions being asked are, Can anhydrous ammonia be applied to dry soil? Will it be held in dry soil? When anhydrous ammonia is injected into soil, several physical and chemical reactions take place: dissolution in water, reaction with soil organic matter and clay, and attachment of the resulting ammonium ions on the cation exchange complex.
Annual Swine Manure Applications To Soybean Under Corn-Soybean Rotation, Allah Bakhsh, Rameshwar S. Kanwar, James L. Baker, John E. Sawyer, Antonio P. Mallarino
Annual Swine Manure Applications To Soybean Under Corn-Soybean Rotation, Allah Bakhsh, Rameshwar S. Kanwar, James L. Baker, John E. Sawyer, Antonio P. Mallarino
John E. Sawyer
The response of a corn-soybean rotation system receiving fall manure application to both corn and soybean is not well understood in terms of its impact on nitrate leaching to subsurface drainage water and crop yields. This field study was conducted from 2001 through 2005 with the key objective of determining the effects of manure application to both corn and soybean on NO3-N concentrations in subsurface drainage water and corn-soybean yields. The study was conducted on 0.4 ha plots instrumented with state-of-the-art subsurface drainage monitoring systems at the Iowa State University research center, Nashua, Iowa. Nitrogen application rates from liquid swine …
45th Annual North Central Extension-Industry Soil Fertility Conference, John E. Sawyer
45th Annual North Central Extension-Industry Soil Fertility Conference, John E. Sawyer
John E. Sawyer
If you would like to learn more about current soil fertility issues and research being conducted at universities across the North Central region, then consider attending the 45th Annual North Central Extension-Industry Soil Fertility Conference on November 4-5, 2015, from 1 p.m. to noon, at the Holiday Inn Airport in Des Moines, Iowa. The conference will include invited presentations from university and industry leaders, research reports from university soil fertility researchers, and posters outlining research by graduate students at universities across the North Central region (Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Nebraska, North Dakota, Ohio, Ontario, Pennsylvania, South Dakota, …
Application Checkpoints For Fall Ammonia, H. Mark Hanna, John E. Sawyer
Application Checkpoints For Fall Ammonia, H. Mark Hanna, John E. Sawyer
John E. Sawyer
Depending on postharvest field conditions, some producers will soon be considering anhydrous ammonia application. Using fall labor to apply fertilizer can be attractive but needs to be balanced with the potential for nutrient loss. To avoid conversion of anhydrous ammonia from ammonium to more leachable forms of nitrogen, application should be delayed until average soil temperature is below 50°F and trending lower. Measure the 4-inch soil temperature at near 10 a.m. or 7 p.m. or check Iowa State University's county soil temperatures and forecast.
Apply Nitrogen Or Plant Corn?, John E. Sawyer
Apply Nitrogen Or Plant Corn?, John E. Sawyer
John E. Sawyer
The end of the optimal time for corn planting is quickly approaching. Getting corn planted should be a priority over making nitrogen (N) fertilizer applications. However, along with that decision there should be a plan to get N applications completed after planting and crop emergence. Switching products and application from preplant to sidedress requires availability of needed fertilizers and equipment. So have a plan in place.
Impact Of Swine Manure Applications On Nitrate And Phosphorus In Subsurface Drainage Water, Rameshwar S. Kanwar, James L. Baker, Carl H. Pederson, Antonio P. Mallarino, John E. Sawyer, Kenneth T. Pecinovsky
Impact Of Swine Manure Applications On Nitrate And Phosphorus In Subsurface Drainage Water, Rameshwar S. Kanwar, James L. Baker, Carl H. Pederson, Antonio P. Mallarino, John E. Sawyer, Kenneth T. Pecinovsky
John E. Sawyer
Nonpoint source nutrient pollution related to land application of manures is recognized as an important environmental and social issue for several reasons. First, manure from swine production facilities can have serious impacts on the quality of ground water resources. Second, several states are in the process of creating laws and/or regulations to reduce nitrogen (N) and phosphorus (P) loadings from manure to soil and water resources. Third, pollution of water resources from nutrients supplied by manure to croplands will help set parameters for developing public policies on the management of manure.
Impact Of Swine Manure Application On Water Quality, Rameshwar S. Kanwar, Carl H. Pederson, Matthew J. Helmers, John E. Sawyer, Antonio P. Mallarino
Impact Of Swine Manure Application On Water Quality, Rameshwar S. Kanwar, Carl H. Pederson, Matthew J. Helmers, John E. Sawyer, Antonio P. Mallarino
John E. Sawyer
Nonpoint source nutrient pollution related to land application of manures is recognized as an important environmental and social issue for several reasons. First,swine manure application to land can impact water quality. Second, several states are in the process of creating laws and/or regulations to reduce nitrogen and phosphorus loadings from manure to soil and water resources. Third, the quality of water resources will help set parameters for developing public policies on management of manure.
Impacts Of Cover Crops On Phosphorus And Nitrogen Loss With Surface Runoff, Antonio Mallarino, Richard Cruse, Dan Jaynes, John Sawyer, Pablo Barbieri
Impacts Of Cover Crops On Phosphorus And Nitrogen Loss With Surface Runoff, Antonio Mallarino, Richard Cruse, Dan Jaynes, John Sawyer, Pablo Barbieri
John E. Sawyer
Iowa research has demonstrated that cover crops can improve soil productivity and water quality by increasing soil organic matter and reducing nitrate nitrogen (N) leaching. Other research has investigated and is investigating the agronomic and economic viability of using cereal rye cover crops in continuous corn or corn-soybean rotations. However, no Iowa research has evaluated under natural rainfall the impact of cover crops on phosphorus (P) and N loss with surface runoff interacting with other management practices. The need for this type of research was indicated in the Iowa Nutrient Reduction Strategy documents. This effort assessed what would be needed …
Impact Of 4r Management On Crop Production And Nitrate-Nitrogen Loss In Tile Drainage, Matthew Helmers, John Sawyer, Josh Sievers
Impact Of 4r Management On Crop Production And Nitrate-Nitrogen Loss In Tile Drainage, Matthew Helmers, John Sawyer, Josh Sievers
John E. Sawyer
Corn Belt corn and soybean producers are increasingly challenged to maximize crop production while addressing the contributions farm practices make to Gulf hypoxia. Based on the need for nitrate-N reductions to meet water quality goals, new management practices are needed to reduce nitrate-N losses at minimal cost and maximum economic benefits. This three-year field research and demonstration project is evaluating various promising N management methods and technologies by documenting the nitrate-N export and crop yield from various systems.
Isu Extension And Outreach Offers Soil Fertility Short Course, John E. Sawyer, Brent A. Pringnitz
Isu Extension And Outreach Offers Soil Fertility Short Course, John E. Sawyer, Brent A. Pringnitz
John E. Sawyer
Making sound soil fertility management decisions is an important part of successful crop production, on both an economic and environmental level. Iowa State University Extension and Outreach will offer a two-day short course focusing on principles of soils, soil fertility and nutrient management to help crop production professionals make better decisions. Highlights include sampling and testing; pH and liming; essential, secondary and micronutrients; nitrogen dynamics; manure management; and more. The small class size allows for increased discussion and interaction with Extension and Outreach specialists.
Valuing Immature Grain Crops As Forage, William M. Edwards, Stephen K. Barnhart
Valuing Immature Grain Crops As Forage, William M. Edwards, Stephen K. Barnhart
William Edwards
Late planted corn, soybeans and oats crops can be harvested as forages instead of for grain. Options include corn or oat silage, earlage, and oat or soybean hay. Estimating a value for these crops is made difficult by the fact there are few reported prices or significant markets in which they are bought and sold. However, there are two other general approaches to valuing grain crops harvested as forage. Both are based on comparisons to alternative actions by either the forage buyer or seller.
Valuing Immature Grain Crops As Forage, William M. Edwards, Stephen K. Barnhart
Valuing Immature Grain Crops As Forage, William M. Edwards, Stephen K. Barnhart
William Edwards
Late planted corn, soybeans and oats crops can be harvested as forages instead of for grain. Options include corn or oat silage, earlage, and oat or soybean hay. Estimating a value for these crops is made difficult by the fact there are few reported prices or significant markets in which they are bought and sold. However, there are two other general approaches to valuing grain crops harvested as forage. Both are based on comparisons to alternative actions by either the forage buyer or seller.
Valuing Immature Grain Crops As Forage, William M. Edwards, Stephen K. Barnhart
Valuing Immature Grain Crops As Forage, William M. Edwards, Stephen K. Barnhart
William Edwards
Late planted corn, soybeans and oats crops can be harvested as forages instead of for grain. Options include corn or oat silage, earlage, and oat or soybean hay. Estimating a value for these crops is made difficult by the fact there are few reported prices or significant markets in which they are bought and sold. However, there are two other general approaches to valuing grain crops harvested as forage. Both are based on comparisons to alternative actions by either the forage buyer or seller.
Drought Effects On Composition And Yield For Corn Stover, Mixed Grasses, And Miscanthus As Bioenergy Feedstocks, Rachel Emerson, Amber Hoover, Allison Ray, Jeffrey Lacey, Marnie Cortez, Courtney Payne, Douglas L. Karlen, Stuart J. Birrell, David A. Laird, Robert Kallenbach, Josh Egenolf, Matthew Sousek, Thomas Voigt
Drought Effects On Composition And Yield For Corn Stover, Mixed Grasses, And Miscanthus As Bioenergy Feedstocks, Rachel Emerson, Amber Hoover, Allison Ray, Jeffrey Lacey, Marnie Cortez, Courtney Payne, Douglas L. Karlen, Stuart J. Birrell, David A. Laird, Robert Kallenbach, Josh Egenolf, Matthew Sousek, Thomas Voigt
Douglas L Karlen
Drought conditions in 2012 were some of the most severe in recent history. The purpose of this study is to examine the impact of drought on quality, quantity, and theoretical ethanol yield (TEY) of three bioenergy feedstocks, corn stover, mixed grasses from Conservation Reserve Program lands, and Miscanthus ×giganteus. To assess drought effects on these feedstocks, samples from 2010 (minimal to no drought) and 2012 (severe drought) were compared from multiple locations in the US. In all feedstocks, drought significantly increased extractives and reduced structural sugars and lignin; subsequently, TEYs were reduced 10–15%. Biomass yields were significantly reduced …
Nitrogen Management Of Winter Triticale, Lance R. Gibson, Carasella Nance, Douglas L. Karlen
Nitrogen Management Of Winter Triticale, Lance R. Gibson, Carasella Nance, Douglas L. Karlen
Douglas L Karlen
Triticale (trit-ah-kay-lee) is a close relative of wheat. When durum wheat is pollinated with rye pollen, the cross is used in a breeding program to produce stable, self-replicating varieties. Triticale yield, stress tolerance, and disease resistance are typically greater than similar traits found in wheat. Triticale does not currently possess the grain traits of bread wheat, so its greatest market potential is as animal feed.