November 1 is just around the corner-the beginning of when fall fertilizing occurs in this area of the State. Hopefully many of you have taken soil samples as excess nitrate is to be expected after this drought year. This is an excellent time to consider evaluating your nitrogen program by starting an on-farm research trial!
On-farm research is using your own equipment, in your own fields, over single or multiple growing seasons allowing you to determine the most economical, efficient, and sustainable practice for the production of irrigated and/or dryland crops on your own farm.
What are the soil fertility questions you have for your farm?
Right now, with fertilizing on producers’ minds, we’re hoping you will consider a soil fertility study. We have several example nutrient protocols including the UNL N fertility rate compared to +/- 30 lbs, and considerations for nitrogen timing studies such as pre-plant, sidedress, or fertigation. You can view all these plot designs by clicking on 2012 protocols. If you are planning on applying anhydrous this fall, be sure that the anhydrous strips are the correct width, as the corn must be harvested and weight determined in a correct manner next fall.
When designing a nitrogen comparison you need to remember nitrogen is a mobile nutrient and corn roots will spread laterally. Therefore, the width of the treatments must take this into account and compensate for it. If you have a 16 row nitrogen applicator and an 8 row corn head, you will need 32 rows of each nitrogen rate. Each 32 row strip must be repeated 4 times. At harvest, in each 32 row block, you must record and weigh the center 16 rows with two separate weights i.e. 8+8 . This is done for statistical analysis purposes. Without statistics, you cannot determine if differences between treatments is the result of the nitrogen rate or because of soil variability.
What’s in It for You?
On-farm research in your own fields allows you to find answers to the questions you may have. We all read articles or hear presentations about various practices and products. The question is “Will it work on my farm?“. That’s what on-farm research allows you to find out!
UNL Extension Educators and Specialists are here to help you design your on-farm research trials, help you with data collection, and will statistically analyze the data for you at the end of the season. Correct plot setup is critical to reduce any error in favoring one treatment over another (because we know fields are variable and some portions of the field will yield better than others). The statistical analysis is another tool which helps us determine how much any yield differences between treatments are due to the treatments themselves or to chance.
So if you have an idea you’d like to try, please contact any of the UNL Extension Educators or Specialists working with on-farm research! The Nebraska On-farm Research Effort is a partnership between the Nebraska Corn Board, Nebraska Corn Growers Association, and UNL Extension.
On-farm research may sound daunting, but today’s equipment makes it easier than ever. It does take a little extra time, but our farmers conducting on-farm research feel the value of knowing the results of a study on their own piece of ground make the effort worthwhile.
What are some on-farm research studies you would like to conduct this year or that you would like our group to consider?
While farmers may be tired of irrigating right now, I think all who have irrigation are thankful for it in such a dry year. Honestly, thankfully with our irrigation we have some of the best looking crops in the Corn Belt right now. Even so, with corn that hasn’t been replanted nearing dent or stages of starch fill, you may be wondering how to schedule for your last irrigation.
For those of you in our Nebraska Ag Water Management Network using watermark sensors, the goal is to use them to determine when the soil profile reaches 60% depletion (for silty-clay soils in our area aim for an average of 160 kpa of all your sensors). You may be thinking, “An average of 90kpa was hard enough!” but as Daryl Andersen from the Little Blue Natural Resources District points out, you’re only taking an additional 0.30 inches out of each foot. So if you’re averaging 90kpa on your three sensors, you have depleted 2.34 inches in the top three feet so you still have 0.96 inches left (see the Soil Moisture Depletion Chart). If you add the fourth foot (using a similar number from the third foot), it would bring the water available to the plant up to 1.28”.
At beginning dent corn you need 24 days or 5 inches of water to finish the crop to maturity. If you subtract 1.28 from 5 you will need 3.72” to finish out the crop. Corn at ½ milk line needs 13 days or 2.25” to finish the crop to maturity-so subtracting it from 1.28 would be only 0.97”.
Soybeans at the beginning of seed enlargement (R5) need 6.5”. Soybeans in R6 or full seed which needs 3.5 inches yet for maturity. Subtracting off the 1.28” in the four foot profile would lead to 2.22”. The UNL NebGuide Predicting the Last Irrigation of the Season provides good information on how determine your last irrigation in addition to showing charts on how much water the crop still needs at various growth stages.
Several people I’ve talked to who have been irrigating using watermark sensors aren’t replenishing the second foot, so you may have a few rounds yet to go on corn and beans. For a quick way to know where you’re at, think about irrigating this way as explained by Daryl Andersen at the Little Blue Natural Resources District:
One way to look at this is by the numbers of days left. At 1/4 starch, there are about 19 days before maturity so you can let your sensors average 130kpa on the first week and 150kpa on the next week. If these targets are met during the week, you would put on about 1 inch of water. By going to these numbers, it might give you a higher probability for rain in the next couple of weeks. I’m hoping for many answered prayers that we will see rain in August!
In early July, southern rust caused by the fungal pathogen Puccinia polysora was discovered in Hall, Adams, Clay, Fillmore, Thayer, and Burt counties in Nebraska. Most farmers in south-central Nebraska remember the corn season in 2006 walking out of fields orange and the slow harvest due to downed stalks. Since then, southern rust has been a disease of concern and fungicides are used to prevent and also treat it when it’s found in fields.
I promised when we were first discovering southern rust this year that I’d post pics, so while delayed, here they are! It is often confused with common rust which we see earlier every year. Common rust typically has pustules (raised fungal spores) that are brick red in color, larger, and on the upper and lower leaf surfaces. The pustules tend to be more spread out.
Southern rust typically has very small pustules that are clustered on predominately the upper leaf surface and are tan to orange in color. This year, southern rust pustules tend to be more tan in color than orange but are still distinctively different with their smaller and clustered appearance. Both fungal rust pathogens arrive in Nebraska each year via wind from the south. Southern rust prefers warm, moist conditions which, in spite of our dry spell, is typical within our pivot and gravity-irrigated fields in the area. At this time we are recommending if you find southern rust in your field to consider treating with a fungicide. Please be sure to read and follow all label directions including paying attention to pre-harvest intervals. A list of corn fungicides and efficacy can be found here by scrolling down to the corn section.
Additional information and pictures of these diseases can be found here.