Equipment Maintenance: Fertilizer Applicators,
2016
Iowa State University
Equipment Maintenance: Fertilizer Applicators, H. Mark Hanna, John E. Sawyer, Michael J. Tidman
John E. Sawyer
Winter is a good time for crop producers and fertilizer dealers to work out the kinks in fertilizer application equipment for economic, environmental, efficiency, and safety reasons. Properly working application equipment translates into getting the most out of every fertilizer dollar. Overapplying to compensate for poorly calibrated equipment wastes money and could mean nutrient-rich runoff and consequently, a potential water quality problem. This article provides some tips for maintaining your fertilizer application equipment.
Estimating Nitrogen Losses,
2016
Iowa State University
Estimating Nitrogen Losses, John E. Sawyer
John E. Sawyer
One method to judge nitrogen (N) loss is to calculate an estimate. Predicting the exact amount is quite difficult as many factors affect losses. However, estimates can provide guidance for supplemental N applications. Excess rainfall this spring occurred in two “periods.” The first arrived early. Loss during that time should have been moderate compared to the same situation that has occurred this late spring. In the early spring, soils were colder, so conversion to nitrate and denitrification was slower. However, wet soils in late spring are warmer and have been saturated for a prolonged period. This significantly increases the chance …
In-Season Nitrogen Fertilization Of Soybean,
2016
Iowa State University
In-Season Nitrogen Fertilization Of Soybean, John E. Sawyer, Daniel W. Barker
John E. Sawyer
Nitrogen (N) fertilization is not a traditional nutrient management practice for soybean production in Iowa. Soybean is a legume plant and is assumed to adequately obtain needed N through symbiotic fixation. However, there is interest in using N fertilization to increase yield and grain protein due to the recognition of the large N requirement associated with high yields. Despite the fact that soybean is a legume, it readily utilizes soil inorganic N and will do so preferentially to symbiotic N2 fixation. Depending on the residual inorganic N level and soil N mineralization characteristics, approximately 40 to 75% of the N …
High Prices And Tight Supply Make Fertilization Decisions Tough,
2016
Iowa State University
High Prices And Tight Supply Make Fertilization Decisions Tough, John E. Sawyer
John E. Sawyer
Nitrogen (N) fertilizer prices have been high the past few years, and continue to be this fall. Additionally, other fertilizer products have increased in price, with supply shortages of potassium (K) fertilizer possible. Why is this occurring? Several factors are interacting to influence both supply and price. These include high natural gas price (main feedstock for manufacture of N fertilizer), closure of about one-quarter of the U.S.
In-Season Nitrogen Fertilization Of Soybean,
2016
Iowa State University
In-Season Nitrogen Fertilization Of Soybean, John E. Sawyer, Daniel W. Barker
John E. Sawyer
Nitrogen (N) fertilization is not a traditional nutrient management practice for soybean production in Iowa. Soybean is a legume plant and is assumed to adequately obtain needed N through symbiotic fixation. However, there is interest in using N fertilization to increase yield and grain protein due to the recognition of the large N requirement associated with high yields. Despite the fact that soybean is a legume, it readily utilizes soil inorganic N and will do so preferentially to symbiotic N2 fixation. Depending on the residual inorganic N level and soil N mineralization characteristics, approximately 40 to 75% of the N …
Getting The Most From Nitrogen Fertilizer Dollars,
2016
Iowa State University
Getting The Most From Nitrogen Fertilizer Dollars, John E. Sawyer
John E. Sawyer
For some producers, high fertilizer nitrogen (N) prices will add significant costs to corn production this year. What management options can producers take to get the most return from added N? Where to apply N and at what rate? Allocate more N to where it is needed most. If your N costs are high, or products are in short supply, then allocate more N to the situations with greatest potential response to applied N. This allocation would be to the most responsive crops and rotations.
How Do Uncertain Prices Influence Phosphorus And Potassium Fertilization This Fall?,
2016
Iowa State University
How Do Uncertain Prices Influence Phosphorus And Potassium Fertilization This Fall?, Antonio P. Mallarino, John E. Sawyer
John E. Sawyer
Crop prices and phosphorus (P) and potassium (K) fertilizer prices have changed significantly in the last two years, and there is considerable uncertainty about future prices. Profitable crop production requires appropriate soil P and K levels, so careful fertilization planning is required. Iowa State University (ISU) soil-test interpretations and fertilization guidelines in extension publication PM 1688, A General Guide for Crop Nutrient and Limestone Recommendations in Iowa (available to order or to download from www.extension.iastate.edu/pubs), were last updated in November 2002. Some important changes were to recommend higher soil-test K (STK) levels for all crops and to update default yield …
In-Season Nitrogen Fertilization Of Soybean,
2016
Iowa State University
In-Season Nitrogen Fertilization Of Soybean, John E. Sawyer, Daniel W. Barker
John E. Sawyer
Nitrogen (N) fertilization is not a traditional nutrient management practice for soybean production in Iowa. Soybean is a legume plant and is assumed to adequately obtain needed N through symbiotic fixation. However, there is interest in using N fertilization to increase yield and grain protein due to the recognition of the large N requirement associated with high yields. Despite the fact that soybean is a legume, it readily utilizes soil inorganic N and will do so preferentially to symbiotic N2 fixation. Depending on the residual inorganic N level and soil N mineralization characteristics, approximately 40 to 75% of the N …
In-Season Nitrogen Fertilization Of Soybean,
2016
Iowa State University
In-Season Nitrogen Fertilization Of Soybean, John E. Sawyer, Daniel W. Barker
John E. Sawyer
Nitrogen (N) fertilization is not a traditional nutrient management practice for soybean production in Iowa. Soybean is a legume plant and is assumed to adequately obtain needed N through symbiotic fixation. However, there is interest in using N fertilization to increase yield and grain protein due to the recognition of the large N requirement associated with high yields. Despite the fact that soybean is a legume, it readily utilizes soil inorganic N and will do so preferentially to symbiotic N2 fixation. Depending on the residual inorganic N level and soil N mineralization characteristics, approximately 40 to 75% of the N …
In-Season Nitrogen Fertilization Of Soybean,
2016
Iowa State University
In-Season Nitrogen Fertilization Of Soybean, John E. Sawyer, Daniel W. Barker
John E. Sawyer
Nitrogen (N) fertilization is not a traditional nutrient management practice for soybean production in Iowa. Soybean is a legume plant and is assumed to adequately obtain needed N through symbiotic fixation. However, there is interest in using N fertilization to increase yield and grain protein due to the recognition of the large N requirement associated with high yields. Despite the fact that soybean is a legume, it readily utilizes soil inorganic N and will do so preferentially to symbiotic N2 fixation. Depending on the residual inorganic N level and soil N mineralization characteristics, approximately 40 to 75% of the N …
Getting Ready For Fall Fertilization,
2016
Iowa State University
Getting Ready For Fall Fertilization, John E. Sawyer
John E. Sawyer
The fall season is a common time for making crop nutrient applications. Soil sampling, and applications of phosphorus and potassium, nitrogen, and manure are a few things to consider as you plan fall fertilization activities.
High Nitrogen Fertilizer Prices -- Again,
2016
Iowa State University
High Nitrogen Fertilizer Prices -- Again, John E. Sawyer
John E. Sawyer
I am often asked what N rate should be applied for corn production. I hesitate to give too simple of an answer, but actually a straightforward rate of 125 lb N/acre for corn following soybean (SC) and 175 lb N/acre for corn following corn (CC) (continuous, second-, or third-year) with good N management works well. If you have followed Iowa State University Extension publications regarding N management over the years, these rates are in the middle of suggested rate ranges provided since at least 1979 (100--150 lb N/acre for SC and 150--200 lb N/acre for CC).
Gypsum: An Old Product With A New Use,
2016
Iowa State University
Gypsum: An Old Product With A New Use, John E. Sawyer
John E. Sawyer
Gypsum is calcium sulfate (CaSO4). Refined gypsum in the anhydrite form (no water) is 29.4 percent calcium (Ca) and 23.5 percent sulfur (S). Usually, gypsum has water associated in the molecular structure (CaSO4·2H2O) and is approximately 23.3 percent Ca and 18.5 percent S (plaster of paris). Gypsum fertilizer usually has other impurities so grades are approximately 22 percent Ca and 17 percent S.
Hailed-Out Soybean Fields,
2016
Iowa State University
Hailed-Out Soybean Fields, John E. Sawyer
John E. Sawyer
An unfortunate hailstorm "harvested" a large number of soybean fields in a swath across northwestern Iowa on October 1. In these fields, the amount of soybean seed knocked from the plants varied from minimal to essentially the entire yield. Although nothing can be done to replace the lost grain, at least nitrogen (N), phosphorus (P), and potassium (K) nutrients returned to the soil in the soybean grain can be accounted for when planning nutrient applications for 2003 crops. An estimate of soybean bushels per acre lost is needed to approximate nutrient return to the soil.
Evaluation Of Fertilizer Additives For Enhanced Nitrogen Efficiency In Corn,
2016
Iowa State University
Evaluation Of Fertilizer Additives For Enhanced Nitrogen Efficiency In Corn, Daniel W. Barker, John E. Sawyer, Michael J. Castellano
John E. Sawyer
The use of N additives and slow release materials with ammoniacal fertilizer varies throughout the U.S. Corn Belt due to differing N loss potentials across climate, soils, and production systems. In Iowa, recent years of high rainfall events and prolonged wet soil conditions has renewed interest to protect fertilizer N loss from denitrification, leaching, and greenhouse gas emission with use of nitrification inhibitors. These loss processes can be significant in Iowa soils that are poorly drained and have high organic matter, high pH, and high populations of denitrifying bacteria. Subsurface tile drainage is also prevalent in farmer fields throughout the …
Fertilizer And Swine Manure Management Systems: Impacts On Agronomic And Environmental Soil Phosphorus Tests And On Phosphorus Loss With Subsurface Drainage,
2016
Iowa State University
Fertilizer And Swine Manure Management Systems: Impacts On Agronomic And Environmental Soil Phosphorus Tests And On Phosphorus Loss With Subsurface Drainage, Antonio P. Mallarino, John E. Sawyer, Jeremy Klatt, Rameshwar S. Kanwar, Carl H. Pederson, James L. Baker, Kenneth T. Pecinovsky
John E. Sawyer
Manure or fertilizer can be used to supply the phosphorus (P) needs of crops. However, excess P application increases the risk of P loss from fields and of water quality impairment through increased algae growth. Poor water quality in many Iowa lakes has prompted questions about the impact of P management practices on P loss from fields and the effectiveness of using agronomic soil tests for environmental purposes.
Fertilizer And Swine Manure Management Systems: Impacts On Crop Production And Nitrate-Nitrogen Leaching With Subsurface Drainage,
2016
Iowa State University
Fertilizer And Swine Manure Management Systems: Impacts On Crop Production And Nitrate-Nitrogen Leaching With Subsurface Drainage, Rameshwar S. Kanwar, Carl H. Pederson, James L. Baker, Antonio P. Mallarino, John E. Sawyer, Kenneth T. Pecinovsky
John E. Sawyer
Nutrient losses from row-crop land can cause nonpoint source water quality problems and “impaired waters.” Nitrogen (N) losses due to nitrate (NO3) leaching cause drinking water problems and possibly increase hypoxia (low oxygen) problems in the Gulf of Mexico. Phosphorus (P) losses can cause eutrophication problems in surface waters (lakes, streams, and reservoirs) in Iowa where algal blooms decrease oxygen, kill fish, and result in murky and bad tasting water. The U.S. EPA and the Iowa Department of Natural Resources are developing nutrient criteria/standards and implementation plans to address TMDL’s (Total Maximum Daily Load) and to improve the quality of …
Fertilizer Nitrogen Application This Fall,
2016
Iowa State University
Fertilizer Nitrogen Application This Fall, John E. Sawyer
John E. Sawyer
Much of the primary fertilizer nitrogen (N) for corn is applied in the spring as pre-plant or sidedress, where efficiency of N use should be greatest. Fall N fertilizer application success can be enhanced by following several suggestions: only use anhydrous ammonia; apply in late fall after soils cool to 50 degrees F (4-inch depth) and are trending cooler (the colder the better, and most years in Iowa this is sometime in November); consider a nitrification inhibitor to further slow nitrification to nitrate; and avoid fall application to soils that are more prone to wetness or leaching (poorly or excessively …
Farm Energy: Energy Consumption For Row Crop Production,
2016
Iowa State University
Farm Energy: Energy Consumption For Row Crop Production, H. Mark Hanna, John E. Sawyer, Dana Petersen
John E. Sawyer
This publication provides an overview of farm energy use related to corn and soybean production in Iowa. Three areas of row crop production--field operations, fertilizer and pesticide application, and artificial drying--are used to illustrate on-farm energy consumption.
Fall Nitrogen Applications And Soil Temperature,
2016
Iowa State University
Fall Nitrogen Applications And Soil Temperature, John E. Sawyer
John E. Sawyer
If you are considering fall application of anhydrous ammonia to corn fields (the only nitrogen fertilizer recommended for fall application), remember to wait until soil temperatures cool to 50° F and continue to trend colder. The same guidance applies to manure with high ammonium N content, like liquid swine manure.
