A result of the 2016-17 winter wheat crop was a significant amount of discussion focused on protein levels. For two years running now, the protein levels have been low across the board. Low protein brings in a challenge to sell, could impact local basis, and even more concerning is that low protein is an indicator that nitrogen was limiting during grain fill. Therefore, the field maximum yield potential was not achieved. In this blog, we talk about what protein is, what can be done to maintain a good protein level, and what can be done to increase protein if desired.
First, the definition of protein is any of a class of nitrogenous organic compounds that consist of large molecules composed of one or more long chains of amino acids and are an essential part of all living organisms, especially as structural components of body tissues such as muscle, hair, collagen, etc., and as enzymes and antibodies. Protein is also one of the many attributes that determines end-use quality and marketability of winter wheat. Sunup TV met with Dr. Carver in the baking and milling lab to create a great video discussing wheat quality impact on baking and milling.
We determine protein by measuring the percent of nitrogen in the grain and multiplying by a factor of 5.7. So if the grain has N % of 2.5, the protein content is 14.25. The amount of N in the grain is affected by many variables such as weather during grain fill, yield level, and N availability during grain fill. If weather is conducive to good grain fill and test weight is high, we will often see protein values dip. On the other hand when grain fill conditions are hot and dry and we have light test weight, wheat protein will be higher. Research has shown (Figures 1 and 2) that generally as yields increase protein levels decrease. Of course if N is limited during grain fill, the N available for the grain is reduced, and the plant is forced to get all grain N from re-immobilizing N in the leaf tissue.
Maintaining Protein, and yield.
Managing nitrogen to maintaining protein and maximizing yield comes down to making sure that N is available at critical growth periods. With wheat, the critical uptake stage is typically the time frame between hollow stem and soft dough. The two graphs below show nitrogen uptake in wheat and barley. If the same graph was made for dual purpose wheat, the upward swing would start sooner but would follow the same general trend.
When it comes to making sure N is available during this time of peak need, the only way we can do that is apply just before it is needed. This means split application. While putting all the nitrogen out pre-plant as anhydrous ammonia is the cheapest method, it is also the method that provides the lowest nitrogen use efficiency and is most likely to show deficiencies late in the season. One of the challenges with 100% preplant N application is that years with good yield potential coincide with years with good/high high rainfall, which means more nitrogen loss. Some interesting results from studies implemented in the 2016-17 cropping season showed the importance of nitrogen application timing. The study is determining how long nitrogen application can be delayed after the N-Rich strip becomes visible (https://osunpk.com/2013/09/19/nitrogen-rich-strips/). For the study, 90 lbs of N was applied on one of the treatments at planting When that plot became visibly greener or bigger than the rest, N application was triggered. After the 0 DAVD (Days after visual difference where the day had growing degree days >0), another treatment was applied every 7 growing days for 63 growing days. Each plot, excluding the zero N check, received 90 lbs as NH4NO3 (we use this to take the variable of volatilization out of the data). In all cases, 90 lbs applied in late January to early February was better than 90 lbs pre-plant. Keep in mind there was 0 N applied at planting for each DAVD application timing; yet, we still hit 50-80 bushel wheat with nothing but in-season N. This is the result of supplying the N when the plant needs it. I should add this is just one year of data, and every year is different. The study is being replicated again this year and will be highlighted at the Lahoma field day.
For dual-purpose wheat, the total amount of N expected for the forage production needs to be applied pre-plant. Oklahoma State recommends 30 lbs N for every 1,000 lbs of forage expected For grain-only wheat, there needs to be only 20 to 40 lbs of N available to the crop when planted (this includes residual N). The remaining N should be applied at green up or early spring. The only way to ensure that N is applied when the crop needs it is to utilize the N-Rich Strip method. Having a N-Rich strip in your field lets you know when the wheat needs more nitrogen and when it does not.
Two years testing the N-Rich Strip and Sensor based nitrogen rate calculator (SBNRC) from the Texas boarder to the Kansas boarder showed that the SBNRC on average reduced N but maintained yield and protein when compared to standard farmer practice (Table 1).
Some producers may plan to market high protein for a premium if available. Fortunately, there are opportunities to increase protein via management. While most of the strategies for increasing protein happen later in the growing season, some of the early decisions can be a significant contributing factor. Variety selection and keeping the plant healthy and free of competition (i.e., pest management) throughout the growing season are going to increase the opportunity to produce high protein wheat. After that, the equation goes back to Figures 3 and 4 and making sure the crop has access to nitrogen during peak periods, including grain fill. If you will note, the bottom two graphs of Figure 5 both show significant increases in protein on the later applications. For both locations, this was when N (90 lbs N ac-1) was applied after full flag leaf emergence. There has been a significant amount of work at OSU looking at late application of N stretching back into the 1990s http://nue.okstate.edu/Index_Publications/Foliar_N_Curt.pdf. The focus has been looking at timing, source, and rate. The take home of decades of work can be summarized as such. Yes, protein can be increased with late season application, but not always. Applying N at or after flowering has a significantly greater probability of increasing protein than a application at flag-leaf. Source of N has had little impact if managed properly (UAN, 28-0-0, has to be watered down so that it does not burn the plant). The rate of N does matter quite a bit. Most of the work suggests that for every pound of N applied, the percent grain protein could increase by .05%. So to increase protein from a 12.5% to 13.5%, it would require approximately 20 lbs of N per acre. My work has shown the same trend that a 20 lbs application at post-flowering had more consistent increases in protein than lower rates at the same time or similar rates applied at flag leaf.
This wheat season we are looking to improve our knowledge of management on protein content through multiple studies by continuing the evaluation of varieties and management practices.
If you have any questions for comments please feel free to contact me.
Its that time of year and I wanted to share my thoughts on nitrogen (N) management in the up and coming winter wheat crop. This season is already shaping up to present certain challenges and opportunities. This blog will highlight many of the topics that were brought up in a recent Sunup TV shoot, video below.
This summer the price of Anhydrous Ammonia (NH3) dropped and producers made a run on NH3 for graze out and dual purpose ground. Currently the price of N is still lower than it has been than it has been in a while and producers are are taking advantage. All things are lining up for this fall to be a good forage year, nitrogen prices are low and we are going into September with a decent soil moisture profile across the wheat belt. If producers can get into the field in a timely manner and we keep getting timely rains it will make a great forage crop. But here is my cautionary statement, if this is a good forage year we are shaping up to be short on N by spring. First the market place over the past two years has overall reduced the amount of inputs into the wheat crops and I would say across the board a lot of the wheat ground is starting out this season with very little residual N. Secondly and more importantly everything which makes for a good forage year makes for a good N loss year, for Oklahoma good rain usually makes good forage. While NH3 does immediately convert to the non mobile ammonium (NH4) form, when soils are warm and moist it does not take long to convert to the mobile and leachable nitrate (NO3) of N. In a recent study looking at N applied at planting in corn, the majority of the NH4 had converted to NO3 by V4, which is usually four to five weeks after planting. Which means NH3 applied in August is likely completely converted to NO3 by September and susceptible to leaching (Since starting this blog in August we have seen a dry down, note the soil moisture on 9.7.17, and abundance of army worms). As the story line has been the low protein wheat of the 2016 and 2017 harvest attention needs to be paid to the crop going into spring.
At Minimum MASS BALANCE the system for dual purpose.
The most simplistic approach to nitrogen management this year is the evaluate what has been made for beef gain and what will be needed for wheat grain yield come the spring. The general rule of thumb is that is takes 1000 lbs of forage to produce 100 lbs of beef gain and depending on the N concentration 1000 lbs of wheat forage will have about 20 lbs N tied up in it. As I talk about on a regular basis, nitrogen use efficiency is not 100% so OSUs rec is 30 lbs of N for each 100 lbs of gain/ 60 lbs of N per ton of forage. On the grain side the standard rule of thumb is 2 lbs of N per bushel. So if the producer applied 100 lbs of NH3 (82 lbs of N) pre-plant and in the spring the average gain is 200 lbs per acre there is only 22 lbs left over for the grain. At that point if we use the field historic average grain yield, lets assume 30 bushel, there needs to be about 38 lbs of N added.
22 lbs (left from pre) / 2 = 11 bushels. 30 – 11 = 19. 2 lbs N per bushel * 19 bushel = 38 lbs of N.
Grain Only Systems
More and more of the grain only producers I am working with are using a 3 pass fertility approach. The approach works this way, No pre-plant N is applied except for what goes down with the seed. In all scenarios this is 40-80 lbs of 18-46-0 which delivers 7 to 14 lbs of N above what is already in the soil (residual N). The second pass comes in winter to early spring before green-up where they are typically applying about 60+ lbs of N. The third pass happens prior to hollow stem. At this point the producers are taking stock of their crop. If the stand is good and soil moisture is good the final application tops them off for the rest of the season. This system is really aided by the application of an N-Rich strip https://osunpk.com/2013/09/19/nitrogen-rich-strips/ . The strip allows the producers to observe the system and know exactly when nitrogen is limited and applications need to be made. Utilizing the Sensor Based Nitrogen Rate Calculator https://osunpk.com/2014/02/24/sensing-the-n-rich-strip-and-using-the-sbnrc/ provides an exact value to the nitrogen needed.
The approach of putting on nitrogen in-season will not only increase the efficiency of the N applied but will help in producing a wheat crop with a good final protein value.
For those wanting to go with the more traditional N application approach of 2 passes I prefer to have no more than 50% of the planned N down at pre-plant. This will allow for a spring green up based upon yield goal. If using the N-Rich strip in a two pass approach I like to see about 30-40 lbs down at pre-plant and then use the N-Rich Strip and SBNRC to fine tune your top-dress which will take place in the spring. Using this technique the research from OSU shows the we can both maximize yield and nitrogen use efficiency.
For the Full Story watch the Sunup TV YouTube video below.
For the last few years I have been challenging people to “Think Out Side the Box” when applying fertilizer. One of these application methods is to use a grain drill to put Nitrogen fertilizer into the soil. Just the act of getting N into the soil will immediately decrease the opportunity for losses. While it seems crazy many picked up on the idea of using grain drills for N applicators. The first year of a two-year study looking at documenting the practice is in the books. With data coming in from three locations, utilizing two drill types (double disk conventional and single disk no-till), the results are quite promising. The biggest take home from year one was a 2 parter: 1) if conditions are conducive to nitrogen loss from urea volatilization, applying urea with a grain drill in the spring improved efficiency. Conversely if loss potential was low, there was no difference. 2) in some soil conditions the double disk drill could not close the furrow and this reduced the positive impact of using the drill. The two tables below show the impact application and environment on yield. Each of the treatments had 60 lbs of nitrogen (as Urea) applied per acre. At Chickasha the first application was made while it was fairly dry and then it rained, but the second application was made during a period in which there was no rain but a fairly significant dew each morning. This can be seen as the small effect volatilization played on the yields of the first application timing. At Lahoma, it was the early applications that had a higher risk of loss with no difference seen later.
With the results from the first year of the top-dressed drilled nitrogen studies in the books, the interest has been increasing. One question keeps popping up: for grain drills without a fertilizer box, what do we put our grain box on to apply fertilizer. At one point the number of inquires hit a critical mass and I sent out my crew to find grain drills and create calibration curves for DAP (18-46-0) and Urea (46-0-0). The crew did just that.
Now please consider what is presented below is a general calibration. Much like the chart on your grain drills, it will hopefully get you close but the best-case scenario is that each drill is calibrate prior to running. As request are made we will try to add more drills to this list.
To create the following charts the guys located several different makes of drills around the OSU experiment stations. They were instructed to choose setting based on the manufacture seed rate charts in the range of 60, 90, 120 etc. For each setting they caught a couple of row units for both Urea (46-0-0) and DAP (18-46-0). They caught each setting multiple times to get a good average.
If you look at the tables you can see the Landol 5211, Great Plains 1006NT, and International 5100 are fairly similar, with the John Deere 1560 being a little lower and the John Deere 450 significantly lower at the lower rates. To use the tables below, consider what kind of grain drill you have and choose to follow one of the drills listed or the average of all five. If you use the average value I would expect most to find they applied a bit more than planned. To make it even simpler, but less accurate, you can use the % wheat value. To do this for DAP take your target rate and divide by .88, this value is what you want to set your drill to. For example for a target rate of 100 lbs DAP per acre use the following formula: 100/.88 = 114. Choose the manufacturer recommended settings 114 lbs wheat seed per acre. If you are wanting to apply Urea take your target rate of urea and divide by 0.71.
Again, I cannot state this enough, this is a general guide, each drill even of the same manufacture and model will likely be different. The only way to be certain of the rate applied is to calibrate each drill individually.
Questions or comments please email me at firstname.lastname@example.org or call 405.744.1722
For 2017 InfoAG I was challenged to review the available mobile scouting apps. While I have been reviewing ag apps since the summer of 2013 https://osunpk.com/2013/07/30/agriculture-app-for-the-ipad-and-iphone/ , I had yet try to tackle a group as complex as scouting apps.My first challenge was to locate all relevant apps. My search began using social media and the search terms Crop Scouting, Field Scouting, Ag Scouting, and Farm Scouting for both iPhone and iPad apps. After a week-long hunt I had found around 30 apps, although I am sure I missed a few. As most of these app require payment, I assumed most would have a 30 day free-trial period. So towards the end of June, about a week out from the meetings, I started trying to gain access. As I did this I kept records in an excel file on how the process was going. I found that with nine apps I had immediate access via the app, for seven apps I was able to request a demonstration, and for another six I used the contact us option and requested a demo via that method. By Friday, July 21st, I had access to 17, my presentation was on Wednesday the 26th. I should note that a few more demos were provided after the presentation, but are not included in this review.
After I gained access I went into iTunes and Google play to determine where they could be found.
During the signup and trial phase most apps offered/suggested/preferred that I went through training for supervised demonstration of their applications. I chose to pass on the training. The first reason was simply due to time constraints, as my presentation data was approaching rapidly by this point. More importantly, I wanted this review to be useful to the people I know that are interested in these apps, and I also know that many of these people are just the type to try something without instructions, you know who you are! So my observations are based entirely on how well I was able to intuitively use the applications. There is no question if I had gone through the training I would have picked up on several items I likely missed. Also it should be noted many of the demo versions I had access to had limited functions.
Evaluation of the apps took place in the field, office, and home. Near the end of the project I spent many hours reviewing notes and going back and forth between the mobile and web based versions.
As I was working through each of the apps, I tried to put myself in the shoes of a private crop scout, much like many of my friends are. This is an important point to consider because as I dug deeper into the applications I came to realize that many of these apps were developed with larger consulting firms in mind. The next table has some important ramifications depending upon the user. Almost every application had a downloadable software or web-based form utilized for operation management. Some of the apps that fell into the category of “Needed to Perform” are the apps which a field boundary or scouting trip could not be initiated from the mobile device.
It is those applications that needed a manager to set fields and/or assign task which I deemed where meant for larger consulting groups, as this strategy would not be efficient for a one or two person operation. These applications did have some impressive functions allowing managers to follow scouts progress and direct operations near real time.
One of the first tasks I wanted to review was the creation of field boundaries. From the view point of a private consultant, I put an emphasis on those apps which could draw field boundaries from the mobile device. The use of CLUs (common land units) was an interesting way to load boundaries, more on that in a bit. Most applications that utilized CLUs did so in the desktop program, however several apps also had the option within the mobile device. A few of the desktop apps also allowed the import of shape files to set field boundaries, it was the only option in Field X.
Drawing field boundaries was the one area that some apps really separated themselves in terms of functionality. For me, the mobile device field boundary winner was the AgDNA app. Their use of the cross-hair with pin drop at the top of the screen increased the accuracy of the pin set. Often, when dropping pins or moving the pins in other apps, the placement would be off due to poor finger to eye coordination. Sirrus and Agrian tied for 2nd, and both provided a zoom option for the pin after placement. AgriSiteIPM provided a nice function where the application dropped an additional pin between any two that I placed. I found this to help speed up the task and allowed me to make some refinements a bit quicker. All other applications were equal.
Now back to the CLU conversation. With CLUs the application draws the boundaries for you. I must say that, when it works properly, it is a very nice function. Below are two examples of fields I used CLUs to define field boundaries.
However CLUs did not consistently identify the proper fields. In the examples below, the L field on the right is actually two separate fields with a dirt road between them, the example on the right only identified the grass waterway and left the field unselected. The saving grace is that all of the apps with CLU option also had the draw option, so if the CLU did not work I could just draw it in manually. So in the long run, no harm no foul.
The next task I evaluated was entering crop/field information, such as crop type, variety/hybrid, planting date, fertilizer, and pesticide applications. My preference was that this task could be accomplished from the mobile device. As it turned out many of the applications which would function better for a larger organization did not allow for this information to be entered via the mobile device. Also, as a soil scientist, I was bummed by the lack of apps with the ability to bring in SURGO data, and even more let down that the majority of the desktop versions did not utilize this data layer. So, with that being said, a big props to FarmLogs for being the only mobile app with the capability of downloading SURGO data layers. Climate had an interesting “soils” portion of the app, where it provided a table listing predominate soil texture, percent organic matter, soil pH and CEC. A note on the Climate soils data, while the soil texture, OM, and CEC are not far off the average, I felt that the pH was off by a bit. This is not unexpected however as, of all the reported variables, pH is the most impacted by human activities.
Below is a summation of the weather functions of mobile and desktop applications. I categorized the data as Historical (multi-year average), Past (either calendar or growing period weather), Current (today’s temp and wind), and Forecast (3-10 day forecast on either a daily or hourly basis). From the consultants viewpoint if I am out in a field trying to determine if I should recommend a nutrient or pesticide application weather is a BIG part of that decision process. So having the current weather and forecast in hand when I have to make that call is a great tool. The past/historical data is something I really enjoyed looking at, and could spend hours doing, its impact on management decision is not as critical as forecast, but is still a tool I appreciated. With that, Climate and Sirrus were the only mobile apps with a forecast function while Farm Logs had nice past data functionality.
Within the Scouting Section I was looking for in field functionality of collecting information and sharing. As expected, all apps provided the ability to drop pins via GPS and add notes and images. Some apps also allowed the user to select the location to drop pins. I liked the ability to add stand counts and a few applications actually allowed the users to collect multiple sampling points and provide an average. This is a nice function that promotes proper sampling techniques. Both Agrian and Sirrus provide directed sampling functions, I specifically liked being able to set up a grid on site and sample immediately. From the aspect of a private consultant, I felt it would be extremely important to be able to share scouting reports and recommendations from the application in-field. Some of these were very simplistic emails others send PDFs.
As far as just “cleanness” and functionality of scouting goes, I personally really liked the scouting layout provided by OpenScout. I also gave good marks to AgraScout and Agrian for their user friendly interfaces.
Personally I am a big fan of having pictures of the pest. Aker Scouts function of having images with their pick list was nice and I could see it really coming in handy. Better yet, when the pest was selected a detailed description was presented. AgraScout also had a nice function that when a pest was selected from the picklist an image of the pest would pop up. Unfortunately, at the time of testing this app had a bug and in the insect picklist the wrong insect often came up.
First look at the ScoutPro I loved its function of a step wise pest selection tool to get too my problem. That said, after a few times it wore me out. I did not need this process to identify pigweed and johnsongrass, and felt it was forcing me to make more clicks than necessary.
The final function hearkens back to my precision ag background. Four of the applications provided the opportunity to build management zones, and from what I could determine from my versions, three of the applications could build and export shapefiles for application. With the image arms race so active right now, I also looked at which applications included satellite imagery. The five listed below are the ones that actively promote the purchase of imagery within the mobile or desktop applications.
The following are comments taken directly from my observations. I have left all notes in this, and in some cases you can see where I could not find a function, then later made a note that it was found.
- Advantage Acre
- Field Select, Auto via image or drop points.
- Nice desktop weather.
- In-field crop info limited.
- Like mobile app scouting functionality
- Trying to set up activity, app shut down
- Cant set up activity without machinery
- Took a while to set up boundaries on app, figured out later.
- List incomplete, no Crabgrass
- No search items (weeds/pest)
- Has a way to document impassable spots
- Recording software. Does a great job of recording activities.
- Can only add crop and planting date
- Looks like you can schedule scouting from desktop
- Dropping pins not that precise.
- If adding in field, cannot scout immediately as it needs assignment.
- Don’t save unless done, locks out event
- Touch issues with corn ear worm (did not bring up ear worm)
- Thinks a lot
- I like the image showing up after the select
- Agronomic Manager App, not one would suggest for private consultant.
- Email notes on single pin,
- does not look like whole scouting trip.
- emails nice PDF
- Finding SURGO Not Easy
- Label available.
- CCA Ready
- AgriSite IPM
- Added fields easily,
- Trouble saving notes Growth Stage was blank, image loading errors.
- Did not always save notes
- Not very intuitive
- Option list was very short.
- Not a fan of the annotations noting method.
- Has Temp and Wind speed on screen
- Seems like a good Manager/agronomist app.
- But not allow on the go field set up is a challenge.
- Farm Dog Scout
- Drops pins, not sure about after fact edit.
- While entering field data if you hit outside of box, you lose.
- Easily adds fields on site
- Has insect and disease list, no weeds.
- Farm Logs
- In App Auto field select.
- Not easy to edit.
- Shows soil type up front when adding field
- Can do from Ipad hooked to internet.
- Really like the image with item search Send Scout via web
- Financial Threat interesting
- Send notes
- Crazy long load time in web.
- Farm Dog Scout
- Drops pins, not sure about after fact edit.
- While entering field data if you hit outside of box, you lose.
- Easily adds fields on site
- Has insect and disease list, no weeds.
- Farm Logs
- In App Auto field select.
- Not easy to edit.
- Shows soil type up front when adding field
- Really nice data trends for rainfall and GDD
- Farm Pad-Tap Logic
- Don’t typically have demos, offered 1 few week then charge card.
- Did offer to provide a developers demo
- A bit clunky in app and Desktop but good functionality.
- Auto Selects boundaries, can not easily edit lines.
- In app adding Nitrogen Application cannot see N source, wont let save
- Field X
- Full Field Note taking,
- Geo Note a point reference app in beta.
- Manager Picklist, Extremely Extensive list.
- But Have to create pick list.
- Needs internet to add from location.
- Very nice scouting function
- Nice infield use.
- AgWorld Scout
- 30 day fre trial.
- satellite view in app moves fast
- Desktop drops a pin, but think it needs shapefile.
- barcode scan
- Needs attributes set up by manager.
- Scout Pro
- Short period
- Love the ID, if I don’t know what I have,
- Don’t like going through steps to Get to something I know.
- Cant Select from Library
- Has a buddy app, that the producer can use to see fields.
- Labels available
- Like the grid soil sample summary on field view
- Performs well for what I would expect a consultant to need,
- would work in a larger comp also.
- CCA ready.
- Sends PDF via email.
My final take home from this task was that I don’t want to have to do this again. It was a wonderful challenge that took a lot of time and energy, and I still only looked at 50% of the available applications. My comments to those looking for an app, reach out and try as many as possible. Every app has its own fit and there is no one size fits all. If you find one or two you like TAKE THE TRAINING, I know I missed aspects of many of these applications, but I was testing the intuitive nature of the programs. My comments to application developers, don’t forget the private consultant. I really don’t feel like many of the applications I tested had the independent consultant in mind. Instead they are targeting large groups, and this is understandable from a marketing stand point. Consider adding a function that, when a scout leaves the field, a note is sent to the producer notifying them that the field has been checked. I can see this being a great value added product, allowing the producer to immediately know that their scout is taking care of them.
Based on a few recent text messages and emails I think it is time to revisit an older post about Corn and Sorghum injuries from pre-plant herbicides.
Direct link to the original post Recent Weather Causing Corn (and Sorghum) Injury From Pre-emerge Herbicides