Source: UNIV OF MINNESOTA submitted to NRP
OPTIMUM NUTRIENT MANAGEMENT IN CORN AND SOYBEAN PRODUCTION IN MINNESOTA
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
1000741
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Oct 1, 2013
Project End Date
Sep 30, 2018
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
UNIV OF MINNESOTA
(N/A)
ST PAUL,MN 55108
Performing Department
Soil, Water, and Climate
Non Technical Summary
Corn and soybeans represent important crops in the state of Minnesota. With yield levels increasing at a steady pace, corn and soybean producers are constantly scrutinizing fertilizer rate guidelines as inadequate for the current varieties or hybrids planted. With cash rent prices increasing and more acres rented, farmers are managing owned and rented land differently in order to keep their enterprises profitable. The current fertilizer guidelines for the state of Minnesota were developed at least 20 years ago and are highly prescriptive when it comes to application rates. With an increased emphasis on best management practices due to water quality concerns for phosphorus, there is increased interest on limiting application rates to University guidelines. These guidelines need to be updated to accommodate current management practices like whole field fertilizer application strategies. Variable rate application is based on the predicated response to nutrient application. Minnesota research in the past five years found that corn and soybean yields could potentially be increased by 20 bushels per acre through grid sampling when low testing areas of phosphorus can be accurately identified. Soil test data, when properly correlated and calibrated provides a risk assessment for determining the relative sufficiency of a nutrient at a given soil test level, it is important to identify those risk areas. The probability of response to a nutrient and the average magnitude of that response are important in defining the relative risks associated with under and over application of fertilizer. Simple correlation and calibration studies of soil tests for phosphorus and potassium are critical to provide this type of information and to ensure data is up to date for use in fertilizer guidelines. Soil testing is the cornerstone of nutrient guidelines in Minnesota. Currently two tests, the Bray-P1 and Olsen, are recommended for phosphorus and one test for potassium, the ammonium acetate test. In neighboring states, the Mehlich-3 test is recommended to determine of both phosphorus and potassium needs for crops and also is preferred by some regulating agencies because it can be used to extract multiple elements at one time from a single sample. Past work with this test has shown it to perform poorly for extracting phosphorus in soils high in calcium carbonate in western Minnesota. There needs to be a better justification for or against using the Mehlich-3 test in the state of Minnesota. While it has been previously researched, past data are not readily available and questions have been more common on use of the Mehlich-3 test. Studying situations where the Mehlich-3 test will and will not work to assess the P sufficiency of crops is critical in determining whether it is used should it be recommended for assessing potential environmental impacts from nutrient applications. Questions have been raised about the effect of drying samples on the amount of potassium extracted using the ammonium acetate or Mehlich-3 test methods. When there is a difference between dry and wet samples, dried samples can test lower, higher, or similar in potassium concentration depending on the soil type and field conditions when the samples were taken. Since potassium is not thought of as a major pollutant to surface and groundwater, the concerns are with soils that will release potassium upon drying. This would results in a high soil test for potassium when in fact the soil may be low that could result in under application of fertilizer and a reduction in grain yield. Currently, we have limited understanding if drying Minnesota soils before testing is leading to incorrect assessment of potassium availability and on what soils there may be a greater concern. Since the analysis of potassium on moist samples is a completely different test and not a standard practice for most labs, there needs to be hard evidence as to the scope of the problem before this test is suggested for widespread use in certified commercial soil testing labs in Minnesota. However, data that supports the use of testing potassium on moist samples is from north-central Iowa with similar soil series and conditions as those in south-central and central Minnesota. If the issue is related to drainage, this problem also may be found in the western and northwestern regions of the state. In addition, with the extreme variability in weather patterns the past two years we have little understanding of the effects of dry weather conditions on soil test potassium levels and how this may also affect the test on field moist versus air dried samples. With the number of questions that crop producers, consultants, and fertilizer retailers have on this issue research comparing the two tests needs to be conducted so we can make a definitive conclusion on whether the moist test should be recommended for use as it is a major change to the current guidelines.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1020199200034%
1021510107033%
1021820107033%
Knowledge Area
102 - Soil, Plant, Water, Nutrient Relationships;

Subject Of Investigation
1510 - Corn; 1820 - Soybean; 0199 - Soil and land, general;

Field Of Science
1070 - Ecology; 2000 - Chemistry;
Goals / Objectives
1) Understand the effect of air drying soil samples on the assessment of the sufficiency of potassium for corn and soybean produ 1a) Determine critical soil test phosphorus concentration by the Bray-P1 and Olsen phosphorus test for air dried samples 1b) Determine critical soil test potassium concentration by the ammonium acetate potassium test on air dried and field moist samples. 1c) Study the variation of soil test potassium levels over the growing season using field moist and air dried samples 1d) Determine the probability and magnitude of corn and soybean response within given soil test classes. 2) Evaluate the Mehlich-3 test for use in assessing the availability of phosphorus and potassium for corn and soybean production in Minnesota
Project Methods
Objective 1 Replicated strip trials will be conducted to study response to phosphorus and potassium. Alternating strips of no- and a high, non-yield limiting rate of fertilizer phosphorus and potassium will be applied. The non-yield limiting rate applied will exceed expected crop needs for 1 year assuming a low soil test level and average crop yields for the studied location (either 200 lbs P2O5 per acre at phosphorus locations and 200 K2O per acre for potassium studies). Soil samples will be collected using a grid cell center approach by taking multiple cores in a concentric circle from the center of the grid. Grid length will be approximately 40 feet long and vary from 30 to 40 feet wide. The grid width will encompass both non- and applied strips. Relative yield of the crop (yield of applied strip divided by no fertilizer strip) will be regressed with the soil test potassium test from the sampling before treatment application. Target crop will be corn and soybean. Soils will be analyzed by soil test methods recommended for the North Central region. The recommended procedure is the ammonium acetate extraction on a dry soil sample for potassium. For phosphorus, the Bray-P1 and Olsen tests will be studied. In addition to the 0-6" sampling, deeper samples will be taken from the 6-12" depths from each grid cell. In the phosphorus studies only the Olsen test will be run on the 6-12" depths. All samples to be analyzed for potassium will be air dried at ambient air temperature while soil samples to be analyzed phosphorus will be dried in a forced air oven on low heat. Oven drying of samples for potassium will be avoided since rapid drying under low heat has been shown to greatly affect fixation or release of potassium from soils. Air drying is more consistent with what is currently being used in commercial labs for potassium samples. Critical soil test levels will be determined using only the 0-6" depths by regressing using two side by side plots with and without fertilizer applied. The yield of the plot without fertilizer will be divided by the plot with fertilizer to determine the relative crop yield then regressed with the soil test value. The 6-12" depths will only be used for covariate analysis to determine if deeper soil depths should be considered when developing critical soil test levels. Soil samples from the 0-6" depth from the potassium studies will be stored in a cooler after collection. Prior to analysis, samples will be sieved through a 0.5" sieve and split in half. Half of the sample will be air dried at ambient temperature and the other half analyzed either directly from a field moist sample or as a soil slurry mix using the ammonium acetate procedure. Soil moisture will be determined based on mass loss upon drying. Soil texture and CEC will be determined on all samples in order to determine if either can explain differences in potassium extracted from between the field moist or air dried soils. Soil samples will be collected from monitoring sites from around the state of Minnesota. Monitoring sites will not be crop specific and will be within grower's field. Thus, fertilizer may be applied at the farmers' normal rates. Sampling depth will be 0-6 inches. Samples will be collected and stored in a plastic bag to keep in a field moist state. Samples will be sieved and split in half with one half will be returned to the cooler and the other half air dried for analysis. Objective 2 The Mehlich-3 test will be run on samples collected from phosphorus and potassium field calibration studies in objective 1. Analysis will be completed on dried samples using the Mehlich-3 method determined with Samples will be separated to those with pH above 7.5 when comparing the soil test methods. In addition, calcium carbonate equivalency will be determined on all samples to determine the effect of this metric on the difference between the Mehlich-3 test and the other two phosphorus soil tests. For the potassium studies, the Mehlich-3 test will be compared with the ammonium acetate test but only on air dried samples.

Progress 10/01/13 to 09/30/18

Outputs
Target Audience:The target audience for this project was ag professionals which include crop consultants, ag industry partners, and state agency personnel and policy makers. While not directly targeted to farmers, the audience served by this project are that which work with farmers having a multiplicative impact by educating a small number who then use that education for a larger audience. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?I do not organize extension events to disseminate information related to this project. However, training and professional development has been provided through outside extension events organized by various groups within Minnesota. The data generated by this project has been in high demand due to low commodity prices. The core focus of this research is on profitable management of phosphorus and potassium fertilizers for which soil testing is used as a important component to assess nutrient availability in soils. How have the results been disseminated to communities of interest?Results have been primarily disseminated through in-person extension events and through web based extension materials. I have focused on increasing the amount of written material released through Minnesota Crop News which goes out to a list of over 2000 people and has commonly generated radio interviews or has been used by local print media. I also have been involved in the development of a nutrient management podcast which is recorded monthly and included various soil fertility topics. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? 1) Understand the effect of air drying soil samples on the assessment of the sufficiency of potassium for corn and soybean production. Additional data were collected from field trials comparing field moist and air dried soil K tests. My long term P-K-S trial was terminated in Fall 2017 at the final two locations. Jeff Vetsch and I also completed work at three long term potassium locations. I compiled the data from several trials for extension presentations given during the early part of 2018 focused on potassium guidelines for corn and soybean. No changes have currently been made to corn or soybean K guidelines but I am working with Jeff Vetsch to finalize data from several studies to be used in a planned update of the fertilizer gudelines. 1a) Determine critical soil test phosphorus concentration by the Bray-P1 and Olsen phosphorus test for air dried samples. I did not have any large research trials on phosphorus in 2018. A ten-year phosphorus study was concluded in 2018. I updated the main P response database updating it through the 2017 growing season. With the update, there were no major changes to the interpretation of current P soil test categories with the update. The current soil test categories will be utilized for the near future in Minnesota. 1b) Determine critical soil test potassium concentration by the ammonium acetate potassium test on air dried and field moist samples. The combined corn and soybean data allowed for a good enough correlation between soil test values for the air dried and field moist tests. The initial work included analysis of corn and soybean data points together. Adding all data allowed for a successful non-linear regression and the determination of critical levels for the combined soybean and corn model. There were differences between the moist and air dried soil test for medium and fine textured soils which will need to be addressed for updates of current potassium guidelines. One additional evaluation which needs to be completed is the current calibrations for the soil test K tests. Long term K data confirms current calibrations used for the current soil test classifications for corn but there is data which indicates some changes may be required for soybean. Additional research trials were established in 2017 to determine if chloride application may impact soybean yield. Data indicates negative yield impacts from chloride which will need to be addressed in any update to the K fertilizer guidelines as potash (KCl) is the major source of K fertilizer for crops in Minnesota. 1c) Study the variation of soil test potassium levels over the growing season using field moist and air dried samples. I continued to collect June soil samples from a set of long-term K studies in 2018. Field moist analysis is only conducted on the June sampling as I have found poorer correlation of fall soil test values to crop response and have begun to scale down multiple sampling for K and focus on times which are more predictive of crop response. 1d) Determine the probability and magnitude of corn and soybean response within given soil test classes. The probability and magnitude of response data was updated prior to the modification of the corn fertilizer guideline publication in 2016. Phosphorus data was summarized and included in the publication update. In late 2017 I updated the K probability of response database. The data collected thus far still does not provide a clear probability function for potassium which has been found for phosphorus. Additional data will be collected beyond the end of this project to further bolster the probability of response database. 2) Evaluate the Mehlich-3 test for use in assessing the availability of phosphorus and potassium for corn and soybean production in Minnesota. No work has progressed on this objective as the major studies comparing the Mehlich-3 tests to the suggested soil tests has ended as of 2018. The data from previous work has been compiled and has shown a good agreements for Mehlich-3 and ammonium acetate potassium results. Phosphorus has been a major issue due to situations where the Mehlich-3 test has been shown to over-estimate phosphorus availability. New trials established in Fall 2018 will further look at the Mehlich-3 P test comparing soils with varying carbonate contents to determine if there is a link between carbonates and sites where the Mehlich-3 test over estimates P availability.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Vetsch, J.A., and D.E. Kaiser. 2018. Evaluation of potassium fertilization strategies for corn and soybean: The buildup phase. p. 145-154. In Proceedings of the 48th North-Central Extension-Industry Soil Fertility Conf. Vol. 34. Nov. 14-15 Des Moines, IA.


Progress 10/01/16 to 09/30/17

Outputs
Target Audience:The target audience for this project is agricultural professionals whom work directly with farmers. The materials provided through this project can be used for the development of fertilizer Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?I donot organize extension events to disseminate information related to this project. However, training and professional development has been provided through outside extension events organized by various groups within Minnesota. The data generated by this project has been in high demand due to low commodity prices. The core focus of this research is on profitable managment of phosphorus and potassium fertilizers for which soil testing is used as a important componentto assess nutrient availablity in soils. How have the results been disseminated to communities of interest?Information has been disseminated to stakeholders through my extension program. In total I presented to around 1300 students at 21 events during the reporting period. Information derived from my phosphorus and potassium research was used at 6 of those events. I also use the material to update 2 extension publications. One of those publications, Both updated publications are only available on the internet. All publications are currently available from the University of Minnesota Extension Nutrient Management Website (z.umn.edu/nutrientmgmt) which had around 500,000 page views during 2017. Page views for this website have increased steadily since it was published live to the web in 2011. What do you plan to do during the next reporting period to accomplish the goals?Work will be completed on two trials, a potassium and a phosphorus study, which were established back in 2009 and data generated has been utlized for this project. I currently have laid the groundwork for updates of the phosphorus and potassium guidelines in Minnesota. During the next reporting period my goal is to complete work on the updates, finish a publication regarding phosphorus soil testing and managment of phophsorus fertilizer, and complete revisions on two to three current phosphorus extension publications. I also am looking to develop additional web based material including news releases on fertilizer managment before the end of the next reporting sesssion.

Impacts
What was accomplished under these goals? 1) Understand the effect of air drying soil samples on the assessment of the sufficiency of potassium for corn and soybean production. Yield data and soil test data for air dried and field moist soil samples were summarized for use in a presentation given at the 2017 ASA/SSSA meetings in Tampa, FL and presented at the Crops and Pest Management Short Course in December. A database was developed using data collected by multiple researchers in Minnesota. 1a) Determine critical soil test phosphorus concentration by the Bray-P1 and Olsen phosphorus test for air dried samples. Additional data collected in 2017 was added to the response database for the determination of critical soil test P levels. The new data did not result in major changes to the interpretation classes. Currently, the soil test classes developed over twenty years ago are still in place as new data has not shown the need for modifying current guidelines. 1b) Determine critical soil test potassium concentration by the ammonium acetate potassium test on air dried and field moist samples. The combined corn and soybean data allowed for a good enough correlation between soil test values for the air dried and field moist tests. The initial work included analysis of corn and soybean data points together. Adding all data allowed for a successful non-linear regression and the determination of critical levels for the combined soybean and corn model. There were differences between the moist and air dried soil test for medium and fine textured soils which will need to be addressed for updates of current potassium guidelines. 1c) Study the variation of soil test potassium levels over the growing season using field moist and air dried samples. I have continued to collect soil samples in fall and in June to compare. In particular, I have collected air dried samples from the same studies in fall and spring to compare changes in the test over time. Three locations were sampled during the current time period of this project. 1d) Determine the probability and magnitude of corn and soybean response within given soil test classes. The probability and magnitude of response data was updated prior to the modification of the corn fertilizer guideline publication in 2016. No additional data has been added to the database. Potassium data has not been generated at this time due to a lack of response to potassium. 2) Evaluate the Mehlich-3 test for use in assessing the availability of phosphorus and potassium for corn and soybean production in Minnesota. I have continued to compile data for comparing the Mehlich III extraction solution for phosphorus. Data was collected from a long term trial during 2017 at six locations across Minnesota. This data has not been combined with past data. Noupdates to current guidelines are planned at this time which would suggest the use of the Mehlich-III soil test in Minnesota. I have identified soils where the test performs similar to the Bray but there are still soils where we can find a poor performance of the Mehlich-III test compared to the Bray-P1 and Olsen-P tests which are currently suggested for use in Minnesota.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Kaiser, D.E. 2017. Minnesota long-term phosphorus trials  Phase II: Sufficiency level vs. build and maintain approaches. p. 25-33. In Proceedings of the 47th North-Central Extension-Industry Soil Fertility Conf. Vol. 33. Nov. 15-16. Des Moines, IA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Leverich, L.M., and D.E. Kaiser. 2017. Influence of phosphorus management on potential for soluble phosphorous loss through leaching. p. 77-90. In Proceedings of the 47th North-Central Extension-Industry Soil Fertility Conf. Vol. 33. Nov. 15-16. Des Moines, IA.
  • Type: Other Status: Published Year Published: 2017 Citation: Pagliari, P.H., D.E. Kaiser, C.J. Rosen, and J.A. Lamb. 2017 The Nature of phosphorus in soils. Ext. Publ. FO-6795-C. Univ. of MN. Ext. St Paul, MN.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Kaiser, D.E., and J.A. Vetsch. 2017. Soil potassium availability to corn and soybean in Minnesota assessed using field moist soil samples. Agron. Abs. CD-ROM. ASA-CSSA-SSSA. Madison, WI.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Fabrizzi, K.P., A.L. Sims, D.E. Kaiser, C.J. Rosen, J.S. Strock, and J.A. Vetsch. 2017. Sufficiency level vs. build and maintain approaches to managing phosphorus for crop production. Agron. Abs. CD-ROM. ASA-CSSA-SSSA. Madison, WI.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Leverich, L.M., and D.E. Kaiser. 2017Influsence of phosphorus management on potential for soluble phosphorus loss through leaching. Agron. Abs. CD-ROM. ASA-CSSA-SSSA. Madison, WI.


Progress 10/01/15 to 09/30/16

Outputs
Target Audience:The target audience for my work has primarily been focused to agricultural professionals which include crop consultants, agricultural retailers, and local, state, and federal agency personnel. This audience has a larger impact as they work with farmers, and in particular, the disseminating information to crop consultants has a broader impact due to the corn and soybean acreage that is impacted. The web based material I generate is available for a wider audience and is being accessed worldwide. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Information generated from this work has been used for an experiential learning program, the Institute for Agricultural Professionals Summer Field School, which was held in July of 2016. There were 100 students that attended the program which was focused on hands on demonstrations related to soil testing and taught the participants some of the issues related to comparing results among soil tests and which tests are best to use under various circumstances. How have the results been disseminated to communities of interest?Information has been disseminated to Stakeholders through my extension program. In total I presented to around 1500 students at 30 events during the reporting period. Information derived from my phosphorus and potassium research was used at only a portion, roughly 25%, of those events. I also use the material to update 3 extension publications. One of those publications, Fertilizing Corn in Minnesota, has been printed to be disseminated to stakeholders. All publications are currently available from the University of Minnesota Extension Nutrient Management Website (z.umn.edu/nutrientmgmt) which had 350.000 page views during the first six months of 2016. Page views for this website have increased steadily since it was published live to the web in 2011. What do you plan to do during the next reporting period to accomplish the goals?Additional research sites will either be established or will be on-going for long-term research work for the next reporting period. Data will be collected from these locations to add to data collected related to objectives 1a 1b, and 1d. I will also be gathering additional data collected from past periods from related studies which I have been collaborating on. One main target is a long-term potassium plot which I have been collaborating on with Jeffrey Vetsch. This study has had lower soil test K values and greater yield responses to fertilizer K. I am not anticipating collecting data for objective 1c and objective 2. At this time there is ample data to answer questions which were generated from these objectives. Soybean data will have to be evaluated during the next reporting period to assess whether changes in the fertilizer guidelines for soybean may need to be made prior to an update of our publication "Fertilizer Guidelines for Agronomic Crops in Minnesota".

Impacts
What was accomplished under these goals? 1) Understand the effect of air drying soil samples on the assessment of the sufficiency of potassium for corn and soybean production 1a) Determine critical soil test phosphorus concentration by the Bray-P1 and Olsen phosphorus test for air dried samples 1b) Determine critical soil test potassium concentration by the ammonium acetate potassium test on air dried and field moist samples. Additional research trials were established in 2016 to collect data relating to objectives 1a and 1b. A database containing corn and soybean response to potassium which includes relative yield produced for the crop and soil test values was previously established. Data from 2015 was added to the database. The 2016 data will be added when available to the database. The database was analyzed prior to the corn guidelines being changed in 2016. At this time the guidelines remain unchanged for K due to a lack of low testing sites which are needed to develop a curve for the correlation between soil test K and corn and soybean yield response. The database for phosphorus was updated with current data, the data were summarized, and corn response to P graphs was included in an update of the publication "Understanding phosphorus in Minnesota soils". Data up to the 2015 growing season was summarized for a proceedings paper which was included in the Proceeding of the North Central Extension Industry Soil Fertility conference and the data was also summarized for a poster presented at the Soil Science Society of America Annual Meetings in Phoenix, AZ. The phosphorus corn database is complete but still need some work to reduce some of the inherent variability in the data with reduces the coefficient of correlation between the soil tests and the relative yield data. The phosphorus dataset is currently providing more useful data used in information developed for stakeholders. 1c) Study the variation of soil test potassium levels over the growing season using field moist and air dried samples The project covering objective 1c was terminated in 2015. A summary of the data was made and reported in the final project report. No further work is planned at this time for objective 1c. 1d) Determine the probability and magnitude of corn and soybean response within given soil test classes. Probability and magnitude of corn response to P was calculated to be included for release with the publication "Fertilizer guidelines for corn production in Minnesota". The database for soybean was also updated but additional data is needed for the database. For potassium no work has progressed due to a lack of yield response at most sites. Further work is planned for corn to add in additional research sites conducted in 2016 from different projects. 2) Evaluate the Mehlich-3 test for use in assessing the availability of phosphorus and potassium for corn and soybean production in Minnesota Comparisons between the Mehlich-3 test and the Bray-P1 and Olsen tests were made for the before mentioned proceedings paper and poster presentation as the SSSA meeting. The data indicates that the test could be used for soils which do not contain appreciable amounts of carbonate. No additional data comparing the Mehlich-3 and ammonium acetate potassium tests as previous work has shown both tests to extract similar amounts of potassium from the soil. No decision was made on suggesting the Mehlich-3 test for use in Minnesota with current fertilizer guideline updates. The primary difficulty with suggesting the tests use is for Western Minnesota for soils that contain carbonate.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Kaiser, D.E., L.M Leverich, J.A Vetsch, and J.S. Strock. 2016. Prediction of corn aand soybean grain yield response to P in Minnesota using the Haney H3A and Mehlich-III tests. p. 179-190. In Proceedings of the 46th North-Central Extension-Industry Soil Fertility Conf. Vol. 32. Nov. 2-3. Des Moines, IA.
  • Type: Other Status: Published Year Published: 2016 Citation: Kaiser, D.E., C.J. Rosen, and J.A. Lamb. 2016. Potassium for crop production. Ext. Publ. FO-6794-D. Univ. of MN. Ext. St Paul, MN.
  • Type: Other Status: Published Year Published: 2016 Citation: Pagliari, P.H., D.E. Kaiser, C.J. Rosen, and J.A. Lamb. 2016 Understanding phosphorus in Minnesota soils. Ext. Publ. FO-0792-F. Univ. of MN. Ext. St Paul, MN.
  • Type: Other Status: Published Year Published: 2016 Citation: Kaiser, D.E., F.G Fernandez, J.A. Lamb, J.A. Coulter, and B. Barber. 2016. Fertilizing corn in Minnesota. Ext. Publ. AG-FO-3790-D. Univ. of MN. Ext. St Paul, MN.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Fabrizzi, K.P., A.L. Sims, D.E. Kaiser, C.J. Rosen, J.S. Strock, and J.A. Vetsch. 2016. Minnesota long-term phosphorus trial-phase II: Testing yield response and potential. Agron. Abs. CD-ROM. ASA-CSSA-SSSA. Madison, WI.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Leverich, L.M., D.E. Kaiser, J.A. Vetsch, and J.S Strock. 2016 Prediction of corn and soybean grain yield response to phosphorus in Minnesota using the Haney H3A and Mehlich-III tests. Agron. Abs. CD-ROM. ASA-CSSA-SSSA. Madison, WI
  • Type: Other Status: Published Year Published: 2016 Citation: Kaiser, D.E., and F.G. Fernandez. 2016. Updates to the corn fertilizer guidelines. http://blog-crop-news.extension.umn.edu/2016/10/updates-to-corn-fertilizer-guidelines.html
  • Type: Other Status: Published Year Published: 2016 Citation: Kaiser, D.E., and F.G. Fernandez. 2016. Updates to corn fertilizer guidelines for 2016. http://blog-crop-news.extension.umn.edu/2016/04/updates-to-corn-fertilizer-guidelines.html


Progress 10/01/14 to 09/30/15

Outputs
Target Audience:Agricultural Professionals: These individuals include crop consultants and retailers that work directly with farmers. This audience is primarily targeted as it has a multiplier effect reaching more acres than a traditional farmer audience. Farmers: A small percentage of my extension education face to face programming is targeted directly to farmers. My publication and website work is targeted to multiple audiences including farmers and agricultural professionals. State and Federal Agency Personnel: I do not specifically target this audience. Since my current position is responsible for maintaining fertilizer guidelines there I do receive questions and have state and federal agency employees utilize some of my education materials. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Most oral extension programming allows for participants to gain continuing education credits for participating in the events. How have the results been disseminated to communities of interest?Data was disseminated through my extension program in oral presentations (25 presentations within Minnesota and 3 presentations in other states) and web based materials released through the Minnesota Extension Nutrient Management Website and through the Minnesota Extension Crop E-News blog. The blogs were written such that they could be released through print media. The number of blogs printed in print media could not be tracked. What do you plan to do during the next reporting period to accomplish the goals?I will be continuing research projects focused on the air dired versus moist K test. There will be a total of 8 trial locations where data will be collected in 2016. I also will be consolidating data from other projects that I have been collaborating on into the corn and soybean K response database to more accurately define the critical soil test K level and ultimately probability and magnitude of response to K for corn and soybean. The phosphorus database is strong enough to utlize in an update of the corn P guidelines which is slated for the beginning of 2016. The purpose of the probability and magnitude of response data was to include in the corn nutrient guidelines to give farmers a tool for determining economics of P fertilizer application in commodity crops. I will continue to add additional data into the corn and soybean databases to continue to strengthen the data included.

Impacts
What was accomplished under these goals? 1a) A large field scale project on critical soil phosphorus (P) test was terminated in 2014 and the data were summarized providing critical soil test levels for the Bray-P1, Olsen, and Mehlich 3 P tests for samples collected from 0-6" depths from the soil surface. Critical soil P levels were found to be near the medium soil test P ranges for current guidelines. Probability and magnitude of corn and soybean response to P were calculated. 1b) Additional samples have been collected from several potassium (K) studies and analyzed by both air dired and moist soil test K methods. A regression analysis was conducted with avaialble data to determine the critical soil test K levels by both air dired and moist K methods. The number of samples taken have, thus far, been insufficient to allow us to determine critical soil test K levels for both tests and to assess probabilty and magnitude of response to applied K with the current database. 1c) Soil samples were collected in fall and in early summer from three long-term K studies to study variation in K test in fall and spring. 1d) Probability and magnitude of response data was generated for the P research. Preliminary data was insufficient to generate probability and magnitude of response to K at this time. 2) Mehlich-3 data was not collected on soil samples taken in 2015 as past research has shown sufficient evidence that 1) the Mehlich-3 test can be used across all soil types for K as data generated shows the two tests to be a 1:1 correlation; and 2) The Mehlich-3 test correlates well to the Bray-P1 and Olsen P tests when soil pH is less than 7.5. When soil pH is greater than 7.5 free carbonate in the soil can lead to innacurate estimation of soil P sufficiency compared to the Olsen P test.

Publications

  • Type: Websites Status: Other Year Published: 2015 Citation: Kaiser, D.E. 2015. University of Minnesota Extension Nutrient Management Website. online at http://z.umn.edu/nutrietntmgmt. Verified 1 Jan. 2015.
  • Type: Journal Articles Status: Submitted Year Published: 2016 Citation: Kaiser, D.E., and J.A. Vetsch. 2015. Optimizing P based in-furrow starter fertilizer n fields with variable soil test P levels. p. 81-89. In Proceedings of the 45th North-Central Extension-Industry Soil Fertility Conf. Vol. 31. Nov. 4-5. Des Moines, IA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Kaiser, D.E., and J.A. Vetsch. 2015. Corn response to phosphorus based starter fertilizer application on the seed. Agron. Abs. CD-ROM. ASA-CSSA-SSSA. Madison, WI.


Progress 10/01/13 to 09/30/14

Outputs
Target Audience: Agricultral Professionsals: These indiciduals include crop conunsulatant and retailiers that work directly wtih farmers. This audience is targeted as it has a muliplier effect reaching more acres than a traditional farmer audience. Farmers: A small percentage of my extension education face to face programming is targeted directly to farmers. My publication and website work is targeted to multiple audiences including farmers and agricultural professionals. State and Federal Agency Personel: I do not specifically target this audience. Since my current position is responsible for maintaining fertilizer guidelines there I do recive questions and have state and federal agency employees utilize some of my education materials. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? I have disseminated results from the soil test calibration research through oral extension education programming and through crop research updates that are released on the web. My oral extension programming is targeted towards my primary audience.My web publications are commonly utilized by agriculture professionals across the state which reaches a wider audience. What do you plan to do during the next reporting period to accomplish the goals? Additional research sites are beingincluded to add additional points of data to the P and K calibration databases. I also am planning on utilizing other data from related projects that can bolster the total amount of data to give a better estimate of critical soil test P and K levels. In order to establish a good database, research must be conducted at many sites to provide a better representation of field conditions across the state. Having more data helps to validate the use of our current nutrient management guidelines across the state of Minnesota.

Impacts
What was accomplished under these goals? 1a) The initial database for critical soil test P concentration in corn has been completed. The data have not been released into the current fertilizer guidelines for corn during the reporting period. Data are still being collected for the soybean database. 1b) One additional year of data was added to the potassium database. Two additional locations were established to collect data in 2014. The potassium database is less developed than the phosphorus database due to a lack of low testing K field areas. 1c) Soil samples were collected and analyzed from 10 locations across Minnesota in 2014. The data are currently awaiting reruns and final analysis. 1d) Probability and magnitude of response data were generated for corn and used in presentations to stakeholders through my extension program in early 2014. Phosphorus data for soybean has not been generated. We do not have adequate potassium data to generate probability and magnitude of response data at this time. 2) Mehlich-3 phosphorus data were collected from two sites and potassium data were collected from two additional sites. The data clearly shows a good correlation with the Bray-P1 test when soil pH is less than 7.5. The test is highly correlated with the ammonium acetate K test regardless of soil pH.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Sims, A.L. J.A. Lamb, D.E. Kaiser, C.J. Rosen, J. Strock, J.A. Vetsch, B. Farmaha, and K, Fabrizzi. 2014. Minnesota long-term phosphorus management trials: Phase 1, the build period. p. 194-202. In Proceedings of the 44th North-Central Extension-Industry Soil Fertility Conf. Vol. 30. Nov. 19-20. Des Moines, IA.
  • Type: Other Status: Published Year Published: 2014 Citation: Kaiser, D.E., J.A. Lamb, and J.A. Vetsch. 2014. Sulfur for Minnesota soils. Ext. Publ. AG-FO-00794-B (revised). Univ. of MN. Ext. St Paul, MN.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Kaiser, D.E. 2014. Interaction of fertilizer phosphorus, potassium, and sulfur in a corn-soybean rotation. Agron. Abs. CD-ROM. ASA-CSSA-SSSA. Madison, WI.