As I write this it does not seem possible that my first Ag App Blog was written over five years ago. https://osunpk.com/2013/07/30/agriculture-app-for-the-ipad-and-iphone/. When I wrote that first blog I had 76 apps on my iPad a year later I had over 200 apps on the same iPad posted the third app focused blog https://osunpk.com/2014/12/09/agriculture-apps-200-strong-and-growing/.
Today I still enjoy looking for apps and I am also having a lot of fun developing apps. With a team of computer science students we have released twenty eight apps in both iOS and Andriod platforms http://www.dasnr.okstate.edu/apps. After I had picked up a few new apps, broke the 300+ mark, I found that my five year old iPad 2 was not quite as quick as it used to be and I had to upgrade prior to doing my Scouting App Review https://osunpk.com/2017/08/03/scouting-app-review/.
Even after 300+ apps I still have a few of the same original suggestions, like the general rule of thumb “If I cannot figure it out in 3 minutes it’s GONE. An app should be intuitive, easy to use and have a purpose. They only exception to the 3 minute rule is the Scouting and Mapping Apps. Because of their complexity I allow them 5 minutes, and then I am done. Any app with GIS in its name gets much more time”. As far as searching for apps terms such as Corn, Soybean, and Wheat return more games and dietary apps than useful ag apps. Multiple key work searchers is important. If you find a good app go into iTunes or Google Play and check out the other apps created by the developer. Chances are if the developer has made one app you like there will be other well suited to your needs.
But to be honest as you can expect of those 300+ apps 95% only get opened when I have to give a talk. Recently I have had request to update my list of apps but instead of spending the countless hours organizing my thoughts on the 300+, I decided on just sharing with you those apps which have made their way onto my cell phone because I do use them. Many of these are on my original blog 5 years ago.
Tank Mix is a handy app that allows the user to create chemical inventories, plan spray jobs, share the details and save for later. Minus wading through the list of chemical this is a very intuitive app and provides a great deal of information. The ability to create a library of chemical and application really streamlines the systems.
SPRAY SELECT Apple
Spray Select was the first app I downloaded. While over the years it has had its fair share of bugs, in my line of work this app is a gem. In a day I may go from spray a contact, to a fertilizer, to a systemic. Not to mention the wide range of GPAs I run at. Being able to to select my speed and GPA then have a list of tips and droplet sizes makes this app critical for my project. I primarily use TeeJet but if you use Hypro check out AgPhDs SprayTipGuide, if you use Greenleaf download NozzleCalc, JohnDeere has an app for their nozzles also.
I have two Nutrient Removal Calculators on my iPhone the Fert Removal from AgPhD and Nutrient Removal from IPNI. I give Fert Removal the leg up because it provides nutrient values for more than just the macro nutrients.
The AgPhDs put out another nice app in Deficiencies. Nice funcitonality but image library is a bit limited. It is my hopes that they are adding to this over time. Much like with the nutrient removal tools I give second runner up in this group to the IPNI PlantImages app. It has a larger image data base but at the time of this blog it needs updating and is not functioning on all platforms. Both apps are on my phone and are great tools for someone new in the field, or someone who has been around a while but who’s client needs to a see a second opinion.
I like the easy of use for of the Corn Yield Calculator. It is a quick, easy, and clean way to estimate yield. However when I pulled the links for this app it seems as though since I first downloaded the app, a fee has been added, $2.99. For some of you it may be worth the charge. However University of Wisconsin has a nice app named Crop Calculators. It has several functions but the UI (user interface) is not as clean.
Another app by the Ag PhDs is on my list. For me the Harvest Loss App is what I use as an example for the perfect “app”. Harvest loss allows the user to choose the commodity and current price. Then the number of grains found in a square foot after harvest is counted. This provides an economic value to properly setting a combine. What more powerful tool than money lost is there to impact change.
These are not the only Weed Identification apps, but they are my favorite. University of Missouri’s IDWeeds was the first of its kind and has made some fantastic improvements over the years. Monsanto’s WeedID app is, IMHO, one of the cleanest and nicest user interfaces available. Both function similarly, the user selects grass or broadleaf, then chooses the appropriate physiological features of the weed in question. A list of weeds fitting the description is compiled. Pictures and more in-depth descriptions are available.
While this app is built for the UK, being in the southern Great Plains wheat is king and this is a very useful app when it comes to cereal disease. While it does not have a good ID tool it has a great list of diseases, images and very in-depth descriptions.
This app just makes me smile. But it really does have some great features and could be quite useful or any cattle producer. By considering the consistency of the pile the quality of the forage/feed can be estimated.
Of course I have all of the OSUNPK apps on my phone but here are a few that I think were homeruns. The full list can be found at http://www.dasnr.okstate.edu/apps
While Canopeo is not mine its the best thing since sliced bread. This app uses the camera on your phone or tablet to get a % canopy cover. The Android version even has a video version. The applications for this app are endless.
OKSTATE SOIL SAMPLE
Designed for individuals who send samples to the OSU Soil, Water, and Forage Testing Labs (SWFAL). User can collect the GPS location of a sample, add notes, and tie it to your lab ID and sample number via a barcode. I know some who just use this app to get Lat Longs from sample points. At this point the app is not tied to the Lab system. But a file can be emailed with all of the saved data.
Simple calculator that will calculate annual nutrient additions when you have a irrigation water test.
Handy app built to help calibrate grain drills to sow canola with the added function of determining rates of other grains and fertilizers.
Non Ag but extremely popular app designed for a DIY food plot. Pick your species of interest and planting window and a list of applicable plants and their agronomic recommendations are provided. Lists can be saved and shared.
Built to help graduate students prep fertilizer for plot application. The app also has a unit conversation calculator.
If you are free in the middle of July, make your way to InfoAg in St Louis (July 17-19, 2018). I will be going through these app and many more in a app review and demonstration. For more info on InfoAg check out their website. https://infoag.org/
Questions for comments fill free to contact me via email at firstname.lastname@example.org
During January and February I spent a lot of time on the road giving precision ag and wheat yield / protein talks. One thing about giving the same talk multiple times and spending countless hours on the road, about 70, is the time you have to think about the little things in your talk. This time around it was the slide below. The graph is from the 502 Long Term Fertility study located in Lahoma OK. When I first put the slide together in 2016 the purpose was to show how the yield and optimum fertilizer rate is extremely varied. I went in to the 55 plus years of yield data and pulled out the past ten years and identified the nitrogen treatment, only those with full P and K fertility, that economically maximized yield each year. With the graph I was able to show how the nitrogen rate required to maximize yield changes dramatically each year and where the amount of N was not directly correlated with yield. But after showing this graph a few times I thought that added lbs of N per bushel would help me highlight the point about changing N demand. That’s the blue numbers below each year. And of course out of curiosity I averaged the numbers. The ten year average was 1.5 lbs of N, which would suggest over a ten year period you would need to apply 120% of the N removed to optimize profit.
The 1.5 lbs per bushel over time was an important number. Not long before I had reached out to half of dozen producers that I have spent at least 5 years with working on their N management. My question to them, what was your average yield and average N rate over all your fields and years. Turns out that most of these producers who were using N-Rich strips and making 2 or 3 trips over the field were averaging 1.5-1.6 lbs N per bushel of wheat produced across a farm. Of course when they told me this I was excited, that’s such an improvement over 2.0 lbs of N per bushel.
The real thought came with me combining these two independent tid bits. Can we provide a Nitrogen Management Report Card if we look at several years of yield history? Let me preface what is presented below is not a scientifically tested or proved concept, yet. The more I think about it the more I am beginning to think that YES we can do a beneficial postmortem analysis. This is not a 1 year analysis, in fact based on the long term data I have been looking at there needs to be 5 years of data per field evaluated. I also strongly contend that this is a by field process. This will provide the opportunity to look at management over a broad spectrum of soil types and weather.
The calculation for lbs of N per bushel is not tough. In a continuous grain only winter wheat system you would add up the amount of nitrogen applied per acre over the period you are evaluating. Sum up the annual average grain yield and multiple that value by 1.3. Divide the total N applied by the total N removed per acre. This will be a decimal value, to compare with the tables below multiple by 100 to get a percent. Based on the long-term trials there needs to be at minimum five years of data. But the more the better.
I would like to reiterate the grades provided below were not developed from any given data set. The report comments are of my own opinion. I do hope in the near future to utilize the Oklahoma State University long-term fertility studies to refine these tables.
For a field with a crop rotation the way to calculate is the same you will just need to go into each harvest and multiple yield by the N in the crop, then sum up those values.
For a field with a crop rotation with legume (or cover crop), I have adjusted the grade scale with the assumption less total N will be needed due to the addition of N fixed by the legumes.
Hopefully with concept will give you a different way to evaluate your N management strategies. This will not and cannot tell you what you need to apply next year. I mean just look at the data from Lahoma, from 2011 to 2015 optimum N rate ranged from 0 to 100 lbs N pre acre and N per bushel grown ranged from 0 to 2.2. Also as you look at the charts, understand that if you follow the old rule of thumbs 2.0 lbs N per bushel winter wheat and 1.2 lbs N per bushel for corn and sorghum, you are likely in the RED. These values are not that wrong for yield goal, 100% preplant application nitrogen management strategy. It is just with today technology, equipment, and agronomic practices we can do a lot better.
My final recommendations/comments would be:
1) If you are in the greens and yellows you are overall doing well. However there is always room for improvement. Are you currently accounting for the temporal variability in N demand, how about the spatial variability?
2) If you are in the orange and reds on the low side, are you there because you are underestimating yield or you are applying less because of grain prices?
There is likely money to be made by increasing yields with a little more nitrogen in these fields.
3) If you are in the orange and reds on the high side, are you there because you are consistently overestimating yield? Perhaps your yield estimation is not off but your lbs of N per bushel value is too high? Are you applying all of your N pre-plant. This practice is the most inefficient way, in terms of N use efficiency, to fertilize.
Questions or comments?
Please feel free to reach out to me via email or phone.
This the recent rains across the dry wheat belt the N-Rich Strips are going to start showing up. Because I am re-posting ans older blog that walks users through the sensing process and inputting data in to SBNRC. But since post we have also release a iOS version of the Online Calculator. iOS N-Rate Calc
With the significant swing in temperature over the last few weeks many are chomping at the bit to get outside. The wheat is starting to respond to the good weather and N-Rich Strips are showing up around the state. Over the past week I have had several calls concerning the impact of the cold weather on the N-Rich Strips. Many of the fields either are still small due to limited days of warm weather and growth or may have a good deal of damage to the foliage. If the field of concern has only a little or no damage and the strip is visible, the time to go is NOW, but if you cannot see the strip and your field has tissue damage or is small, similar to the first two images, then you will need to wait a week or two for sensor based recommendations. Another situation fits with the third image, the field has freeze damage but the N-Rich Strip is also visible. In this case the predicted yield level would be reduced do to the dead tissue making the N rate recommendation a little off. I still however recommend using the sensor and online SBNRC (http://www.soiltesting.okstate.edu/SBNRC/SBNRC.php) to make or base top-dress N rate. Even if the recommendation is a little off it will still be much more accurate than just guessing. However you must look at the SBNRC and ensure that it makes agronomic sense, if it does not consult your county educator or myself. This is discussed in more detail in my earlier blog about freeze damage. Keep in mind no matter what, if you can see the N-Rich Strip, everything outside of the strip is suffering from nitrogen deficiency. Decisions and fertilizer applications need to be made soon, to maximize yield.
Regardless of whether or not the strip is visible you should be planning to sense with the GreenSeeker Handheld very soon. Remember the sensor has the ability to detect differences before your eyes can. To sense the N-Rich Strip and Farmer Practice the user should carry the sensor approximately 30 to 40 inches above the crop canopy while holding the sensor level over the crop. While you are walking the two area the trigger should be held the entire time. I recommend walking at minimum 100 paces for each. The average NDVI value seen on the screen will only stay on the screen for a few seconds. Therefore it is critical you have a method of recording the number for later use. The sensor has limited memory so it will time out is the trigger is held for an extended period of time. If you wish to collect more NDVI readings just do it in multiple trigger pulls recording each. Once you have the average NDVI for the N-Rich Strip and Farmer Practice you can go to the SBNRC site mentioned above to retrieve the N rate recommendation. Once in the calculator, for those in Oklahoma, choose the “within Oklahoma” option in the bottom left hand corner of the screen. This will allow the calculator to access the Oklahoma Mesonet to determine growing degree days. After the location is picked from the options you will need to enter Planting Date and Date Prior to Sensing. Additional information requested is the expected grain and fertilizer prices. While these inputs will provide some economic evaluations they will not impact recommended N rate.
Below is a YouTube video in which I describe how to use the GreenSeeker to collect NDVI readings, describe the data needed to complete the online calculator, and how to interrupt the calculators output.
Normally the alarm for beginning wheat topdressing gets sounded right away in early January. However, it might be understatement to say this year has been dry so far – “drier than a popcorn fart” may be a better description. At the time of writing this blog, a significant portion of the Oklahoma wheat belt has now gone 90+ days with less than 0.25” of rain. The great folks at Mesonet reminded us on January 18 that the long term forecast is not providing us much hope either.
Because it has been dry and no significant rain is in the current forecast, the question is what do we do now about topdressing? This is a tough question to answer as there is not a really “good” option at the moment to be honest. Here are some thoughts to consider:
- In the parts of the state where it is dry and dry deeper than the majority of the rooting zone (> 6”), we should not worry about filling up the nitrogen tank as long as the water tank is empty. As it stands currently, the best option is to hold off for now and wait to apply topdress N right in front of a real chance of rain. The good news is we still have some time yet to get N applied and not limit yield potential if we do get that rain. Ideally, we need the N down in the rooting zone just prior to jointing. Several things, including the number of potential grain sites, are determined just prior to jointing, and it is imperative that the plant has the fuel it needs to complete these tasks. Jointing occurs around the end of February in southern OK and around the second week of March in northern OK. Jointing also marks the beginning of rapid nitrogen uptake by the plant which is used to build new leaves, stem, and the developing grain head. The nitrogen stored in these plant parts will be used to fill the grain later in the season, and the plant is dependent on this stored nitrogen to complete grain fill. And while it does seem like it right now, we still have the potential to make a decent crop if we can get rain before we break winter dormancy. If we do not get the rain though soon as it is appearing, we will not have spent as much money on this crop by holding off on topdress N, and the likelihood of getting the return on our N investment goes down as our yield potential goes down.
- What we can and should do right now is apply N-rich strips. An N-rich strip can help put your mind more at ease by taking the guesswork out of knowing if nitrogen needs to be applied and how much should be applied. The N-rich strip can be as simple as using a small lawn fertilizer spreader with a bag of urea. You local county extension educator can also provide more information on N-rich strips and even has access to lending small fertilizer spreaders!
For those producers who have too much ground and cannot cover all of it just prior to a rain or for those who want to apply now as they are worried about nitrogen being limited after it does start raining, here are few more considerations:
- For conventional-tilled fields that have limited to no residue, applying UAN through streamer nozzles is an okay option. Why? With UAN, there is a very high percentage of soil-fertilizer contact. This immediately improves the efficiency compared to urea. In fields with crop residue, flat fan nozzles are not recommended right now as the likelihood up of N tie-up is too high.
- For no-till fields, the two big concerns are ammonia (NH3) volatilization with dry urea and tie-up on the residue with liquid UAN. Picking the best option in this scenario is a much tougher decision with not a real good conclusion. So, here it goes. If there is tall standing stubble with dry soil below, the dry urea gets the edge. Why? If the stubble is not in a mat, the urea prill can work its way down towards the soil surface. If it can get there, it is out of the high winds, and it will remain there until we get a rain, heavy dew, or increase in humidity. Is there still a chance for loss due to volatilization? Absolutely. Again, it goes back to whether there is any chance that you can wait to apply?
- There have been some questions about using urease inhibitors with broadcasting urea. That is a good question, but it is hard to make an argument for their use until we get a good chance of rain in the 10-day forecast. Typically, these products do not have the life span to hold off urease (i.e., the enzyme that breaks urea into NH3) for more than 10-12 days.
The latter points also apply to those who use the local co-op or ag retailer for application. Some of these groups require 30 days or more to cover all of the acres they service.
Since it is dry and we still have some time yet to apply N, this may turn out to be the perfect year to topdress urea with a grain drill. For those interested in this method, you can find research results from last year on this topic, as well as a calibration guide, by clicking here . More information about nitrogen applications that are “thinking outside the box” can be found by clicking here.
For more information contact Brian Arnall or David Marburger.