Welcome to NPK et cetera, from the desk of Carrie Laboski

Blog Articles


Time your spring nitrogen applications to maximize winter wheat yield

Posted on March 9th, by Carrie Laboski in Nitrogen, Wheat. No Comments

Proper timing of spring N application can significantly increase winter wheat yield. Figure 1 shows the yield obtained at the economic optimum N rate (EONR, N rate where profitability was maximized) when N was applied in spring at green-up or at growth stage 30 (GS30, hollow stem – just prior to first node). At all sites except Lamartine-15, yield was greater when N was applied at green-up compared to GS30. Averaged over all sites, there was a 10 bu/a advantage to applying N at green-up. Applying additional N can not compensate for the yield loss caused by applying N at the later timing as demonstrated by the data in Figure 2.

To maximize yields, growers should try to apply N as soon as possible in the spring, taking into consideration soil physical conditions. Applying N when the ground is barely traffickable … Read More »


Strategies to Maximize Return on Fertilizer in 2016

There are numerous economic challenges for crop production in 2016. Tips for maximizing your economic return on fertilizer are provided in the video titled: “Strategies to Maximize Return on Fertilizer in 2016”. You can find the video here: https://www.youtube.com/watch?v=iokyz0CirWg


Relative Importance of P and K for corn and soybean in Wisconsin

Posted on February 2nd, by Carrie Laboski in Corn, Fertilizer, Nitrogen, Nutrient recommendations, Phosphorus, Potassium, Soybean. No Comments

Phosphorus and potassium are important for crop production. But is one nutrient more important than the other? To learn the answer to this question, watch a new video titled: “Relative Importance of P and K for corn and soybean in Wisconsin”.  This video highlights on-going research conducted at the Arlington Ag Research Station. You can find the video here:  https://www.youtube.com/watch?v=n_sE94mrDqY


Reminder: August 19 – Agronomy/Soils Field Day at Arlington

Posted on August 7th, by Carrie Laboski in Extension Program, Uncategorized. No Comments

The Departments of Agronomy and Soil Science in conjunction with the Arlington Agricultural Research Station will host their annual field day on August 19, 2015. The field day will highlight UW-Madison research on emerging technologies and relevant crop production issues. The field day will begin at 8:00 am and run until 2:30 pm. Lunch will be provided by the Badger Crops Club ($5 donation). View the field day flyer: http://bit.ly/1fihS55


2015 Agronomy/Soils Field Day at Arlington on August 19th

Posted on June 18th, by Carrie Laboski in Uncategorized. No Comments

The Departments of Agronomy and Soil Science in conjunction with the Arlington Agricultural Research Station will host their annual field day on August 19, 2015. The field day will highlight UW-Madison research on emerging technologies and relevant crop production issues. The field day will begin at 8:00 am and run until 2:30 pm. Lunch will be provided by the Badger Crops Club ($5 donation). View the field day flyer: http://bit.ly/1fihS55


Save the Date – Agronomy/Soils Field Day at Arlington Ag Research Station on August 19th

Posted on May 12th, by Carrie Laboski in Extension Program. No Comments

The Departments of Agronomy and Soil Science in conjunction with the Arlington Agricultural Research Station will host their annual field day on August 19, 2015. The field day will highlight UW-Madison research on all facets of crop production and soil management. More details coming in June.


Safe rates of seed placed starter fertilizer

Posted on April 21st, by Carrie Laboski in Corn, Fertilizer. No Comments

Without fail every year after planting, questions start popping up about pop-up fertilizer. The questions always occur when there are emergence or germination issues. So before planting gets into full swing, let’s think about seed placed starter. For the purpose of this article I will use seed placed, pop-up, and in-furrow interchangeably.

Why are fertilizer salts a problem?

Excessive concentrations of fertilizer salts near a germinating seed or seedling root causes injury. The injury is caused when the concentration of ions in the soil is greater than the concentration of ions within the plant cells. The high osmotic pressure created by the fertilizer salts causes water to move out of the plant cells and into the soil. As water moves out of the plant cells, the tissue dessicates and becomes blackened; hence the term fertilizer burn. The result is the eventual … Read More »


Soil, Water, and Nutrient Management Meetings to be held in December

Posted on October 27th, by Carrie Laboski in Extension Program. No Comments

The annual Soil, Water, and Nutrient Management Meetings will be held December 2 through 11 at eight locations throughout the state. Current soil science research will be highlighted along with other topics of interest to agronomists, ag retailers, conservation professionals, and farmers.

Francisco Arriaga, Asst. Professor of Soil Science, will discuss using soil health concepts for management decisions along with understanding corn residue decomposition. Carrie Laboski, Professor of Soil Science, will provide an update on N sensors research for corn and wheat along with how to improve alfalfa productivity with S and K. Precision ag technologies for soil conservation and variable rate practices will be presented by Brian Luck, Asst. Professor of Biological Systems Engineering. Matt Ruark, Asst. Professor of Soil Science, will provide an update on cover crops research and understanding biological measures of soil health. Wisconsin Department of Agriculture, … Read More »


North Central Extension-Industry Soil Fertility Conference Announced.

Posted on September 18th, by Carrie Laboski in Extension Program. No Comments

The North Central Extension-Industry Soil Fertility Conference will be held on November 19-20, 2014 in Des Moines, IA. For more information see: http://www.ipni.net/ncsfc.


2014 Agronomy/Soils Field Day at Arlington on August 27th

Posted on July 24th, by Carrie Laboski in Alfalfa, Corn, Extension Program, Nitrogen, Soil sampling, Soybean, Wheat. No Comments

The Departments of Agronomy and Soil Science in conjunction with the Arlington Agricultural Research Station will host their annual field day on August 27, 2014. The field day will highlight UW-Madison research on emerging technologies, greenhouse gases in agriculture, and relevant crop production issues. FMI: http://bit.ly/1rDZWWf


Fall soil sampling: Another challenging prospect?

Posted on September 17th, by Carrie Laboski in Soil sampling. No Comments

The dry conditions over the past four plus weeks may be giving you flash backs to 2012 and leave you wondering when you should soil sample this fall. Keep in mind that sampling very dry soil may provide erroneous soil test results for several reasons:

1. It is difficult to sample to the desired depth consistently.

2. The soil core does not stay intact, particularly when the surface soil is very dry, and some of the soil is lost between taking the probe out of the ground and placing the sample in the bucket.

3. Soil test P and K may be lower with smaller differences for P and larger differences for K.

4. pH may be slightly lower because of salt build up from a lack of rain.

Once rainfall has occurred, soils will begin to re-equilibrate and the effects of dry conditions on … Read More »


2013 Agronomy/Soils Field Day at Arlington on August 28th

Posted on June 27th, by Carrie Laboski in Extension Program. No Comments

The Departments of Agronomy and Soil Science in conjunction with the Arlington Agricultural Research Station will host their annual field day on August 28, 2013. The field day will highlight UW-Madison research with a theme of “Risk Mitigation in Today’s Economic Climate”. FMI: http://bit.ly/17FtI3U


Potential for Nitrogen Loss Following Heavy Rainfalls

Posted on June 26th, by Carrie Laboski in Corn, Nitrogen. No Comments

Rainfall totals over the past week (June 19 to 26) in the southern half of Wisconsin range from 1 to 15 plus inches. Many soils are saturated and some fields have had or still have standing water in all or part of the field. The million-dollar question is: How much nitrogen (N) loss should I expect from denitrification or leaching and what should I do about it? To answer this question, we’ll consider each situation independently.

Denitrification

Denitrification is the process whereby nitrate is converted to the gases dinitrogen or nitrous oxide and subsequently released to the atmosphere. This conversion is carried out by soil bacteria. Denitrification can be a significant mechanism for N loss on medium- and fine-textured soil. It is generally not an issue on coarse-textured soils because they do not remain saturated for any length of time. There are … Read More »


Update on Soil Profile Nitrate Concentrations

Posted on May 15th, by Carrie Laboski in Nitrogen, Soil sampling. No Comments

The soil nitrate monitoring network website was just updated with soil profile nitrate concentrations for 26 sites throughout Wisconsin. The results are not unlike two weeks ago. Some sites had large losses of nitrate over the winter while others had moderate or typical losses. Nitrate in the soil profile remains high in some locations. Follow guidelines in articles on May 2 and April 25. You can see all of the data at: http://uwlab.soils.wisc.edu/soilnitratemonitoring/. The website will be updated again next week.


August 2013 Nitrogen Use Efficiency Conference in Kansas City

Posted on May 15th, by Carrie Laboski in Nitrogen. No Comments

I’m passing along some information about a N use efficiency conference that may interest you. Managers and advisers on cropland N management will be meeting with other stakeholders to explore the most effective and efficient N sources, implementation of 4R nutrient management, and adoption of technology tools to meet economic, environmental and social goals. Practicing agronomists, crop advisers and extension workers are especially invited to the conference. More details on the conference agenda, registration, and lodging may be found at: https://www.soils.org/meetings/specialized/nitrogen-use-efficiency.


Heavy rainfall causes loss of carry-over nitrogen on some fields

Posted on May 2nd, by Carrie Laboski in Corn, Nitrogen, Soil sampling. No Comments

Last week I answered the question: “Are chances for carry-over N diminishing?” The short answer was maybe. Large amounts of precipitation from last fall to this spring provided the conditions necessary to have nitrate leaching, even on medium- and fine-textured soils. Last week only limited soil profile nitrate data was available to evaluate the situation. In the samples collected on two dates from different fields, it appeared that nitrate was moving down in the soil profile, but may not have moved out of the rootzone.

This week we received soil profile nitrate data from 17 locations representing 28% of the locations in the soil nitrate monitoring network that was established last fall to track the potential for carry-over nitrate from the 2012 drought. Table 1 provides data for these 17 locations. It can also be found at: http://uwlab.soils.wisc.edu/soilnitratemonitoring/. At all locations … Read More »


Nitrogen Credits Following Winter-killed Alfalfa

Posted on May 2nd, by Carrie Laboski in Alfalfa, Nitrogen. No Comments

As alfalfa is greening up across the state, it is becoming apparent that there is a varying amount of winter-killed alfalfa. Based on the amount of winter-kill in a field, some producers may decide to terminate the alfalfa and plant corn instead. It is important to remember that alfalfa N credits should still be taken for this year’s corn crop.

Alfalfa N credits are based on soil texture (medium-/fine-textured or sands/loamy sands), amount of regrowth at the time of stand termination, and number of plants per square foot (Table 1). The method of stand termination (herbicide vs tillage) and time of termination (fall vs spring) do not affect N credits. Where N credits following winter-killed alfalfa may differ from typical stand termination methods is related to decisions surrounding whether or not a first cutting of alfalfa is taken prior to terminating … Read More »


Are Chances for Carry-Over Nitrogen Diminishing?

Posted on April 25th, by Carrie Laboski in Nitrogen, Soil sampling. No Comments

With last summer’s drought throughout much of the state, we headed into winter with variable and sometimes high (eg. 325 lb N/a) amounts of nitrate remaining in the soil profile. One of the key factors determining whether or not this excess N will be available for the 2013 crop is the amount of over-winter precipitation. When over winter precipitation is normal, the potential for N carry-over is low on sandy soils, medium on loams, and high on silt loams and silty clay loams. Precipitation throughout southern and central Wisconsin from October 1, 2012 through April 25, 2013 is greater than normal (Figures 1), which suggests that the potential for carry-over N may no longer be high on silt loam soils in southern and central Wisconsin.

Figure 1. Precipitation departure from normal, October 1, 2012 through April 25, 2013. From http://water.weather.gov/precip

 

The soil nitrate monitoring network … Read More »


Managing Nutrients on Wisconsin Soils Webinar Workshop

Posted on February 14th, by Carrie Laboski in Extension Program. No Comments

Managing Nutrients on Wisconsin Soils Workshop is being offered in a webinar format this year with a revised/updated curriculum. The 2013 workshop webinars will be March 18, 19, and 21 from 1 to 4 pm.

This is an intensive nine-hour webinar designed for agency and industry personnel who desire to have a more in depth knowledge of intermediate to advanced topics in soil fertility and soil management.  The learning objectives are to provide individuals with a fundamental understanding of Wisconsin’s revised nutrient application guidelines, advanced soil fertility management tools that may be used in adaptive nutrient management, and soil management practices to reduce nutrient loss.

More details, including an agenda and registration information, can be found in this flyer: Managing Nutrients on Wisconsin Soils Webinar – 2013


Wondering how much nitrate might be left in the soil from the 2012 crop?

Posted on February 14th, by Carrie Laboski in Corn, Nitrogen, Soil sampling. No Comments

Drought conditions throughout much of Wisconsin in 2012 resulted in yields that were less than growers had been planning for when they planted in the spring. Under drought conditions, there is the possibility that the drought stressed crop did not use all of the nitrogen that was applied. This unused (or residual or excess) N will remain in the soil profile until it is used by another crop or leached. Situations with the greatest potential for excess N to remain in the soil profile after the 2012 crop include fields with drought stressed corn, where manure was applied for the 2012 crop, or where forage legumes were grown in 2011. If fall, winter, and early spring rainfalls are normal or below normal, it is likely that unused N from 2012 will still be in the soil profile in spring 2013 … Read More »


A2809 Update Coming Soon

Posted on November 16th, by Carrie Laboski in Alfalfa, Corn, Nitrogen, Nutrient recommendations, Soil sampling, Soybean, Wheat. No Comments

University of Wisconsin-Extension Publication A2809 Nutrient Application Guidelines for Field, Vegetable, and Fruit Crops in Wisconsin has been revised. There are numerous changes to this edition that are designed to simplify and customize the nutrient recommendation process. A few specific changes include: 1) a reassessment of soil yield potential and a transparent description of how they are defined based on soil properties; 2) a refinement of our P and K recommendation philosophy; 3) updated N rate guidelines for corn; 4) wheat N rate guidelines using a MRTN approach; and 5) updated manure nutrient availabilities.

To learn more about the changes to A2809, attend one of the Soil, Water, and Nutrient Management Meetings that run from November 27 through December 6. Two hours of the meeting will focus on A2809. For more details about the meetings see: http://www.soils.wisc.edu/extension/cal/2012area.pdf

The updated edition of A2809 … Read More »


When should I soil sample this fall?

Posted on September 21st, by Carrie Laboski in Soil sampling. No Comments

This past summer’s drought has left some wondering when they should soil sample this fall. Sampling very dry soil may provide erroneous soil test results for several reasons:

It is difficult to sample to the desired depth consistently.
The soil core does not stay intact, particularly very dry surface soil, and some of the soil is lost between taking the probe out of the ground and placing the sample in the bucket.
Soil test P and K may be lower with smaller differences for P and larger differences for K.
pH may be slightly lower because of salt build up with lack of rain.

Once rainfall has occurred, soils will begin to re-equilibrate and the effects of dry conditions on soil test P, K and pH will diminish. It is hard to provide an exact amount of rainfall that is needed to alleviate the effects … Read More »


Fertilizer Needs for Wheat following a Drought

Posted on September 7th, by Carrie Laboski in Nitrogen, Wheat. No Comments

As preparations are made for planting the 2013 wheat crop, growers should consider how the 2012 drought might impact their fertilizer needs. There is a strong possibility that there will excess (carryover or residual) N in the soil profile after the 2012 corn crop is harvested because the corn was too affected by drought to use all of the applied N. If soybean is the previous crop, there is a low likelihood of excess N remaining in the soil profile. Regardless of previous crop, some of the P and K applied last year will be available for the wheat crop.

 

In the fall of 1988 following a summer drought, 150 to 450 lb NO3-N/a were found in the soil profile after corn harvest at five locations around Wisconsin. At seven different locations, spring 1989 soil profile nitrate concentrations ranged from 98 … Read More »