Nitrogen and Wet Spring (Again)

Wet weather dramatically affects the amount of nitrogen available from the soil to the corn crop. Once again we've seen a lot of water moving through the soil profile, delaying planting and flushing nitrates through the soil profile. Under the ponds we call corn fields, nitrates are being lost to denitrification (conversion of NO3 to N2). The lack of soil oxygen (driven out by water) and cool soil temperatures have slowed the microbes that eat carbon (last years residue) and release soil N to the crop. This process, called mineralization is linear to soil moisture. When conditions are challenging for crop growth, they are challenging for mineralization.

Once the soils dry out, the soil Nitrogen availability won't improve immediately. Those same microbes will be first in line for any Nitrogen as they begin to digest the carbon in last years residue, this process is called immobilization. This is the reason spring Anhydrous fields with no other N source often get off to such a rough start. Jump-starting this process in the fall is the reason Hintzsche advocates Trash Buster, applying Ammonium Sulfate in the fall with P and K applications.

A 3.5% soil can contribute from 70 to 200 pounds per acre of Nitrogen. One of the factors behind bumper crops is large contributions of Nitrogen from the soil (2006). Having a measurement of the soil's contribution can influence sidedress decisions. To monitor these complex interactions, The PRA/Hintzsche team will be pulling nitrate tests weekly through the growing season to monitor the soil's contribution to the Nitrogen availability. Each week, we will report back on this website the nitrate reading at several different Hintzsche locations.

View the chart.

Hintzsche remains committed to improving Nitrogen efficiency. Many Hintzsche growers are using .85 to .9 # of N/bu as their goal and achieving that goal. Last year 9 different growers in the HZ Nutritrack program achieved .9 # N per bushel or less (corn on corn)! The average of all growers was .98 #N/bu for corn on corn. So how do we improve that number?

One avenue we are testing is Humic acid. Humic acid is the most stable form of organic matter. Humic acid creates "exchange sites" that enhance the soil's ability to hold cations like K, NH3, and Ca, and have the ability to chelate ions like Phosphorus, Calcium, Zinc, Manganese and Iron. Adding exchange sites looks to be a huge benefit on light soils, enhancing the ability of these light soils to hold nutrients. I am interested to see if this could be a way to increase the late season availability of Nitrogen from the Nitromax sidedress. This summer, the PRA department will be testing Humic Acid (the brand is Hydra-Hume) in Nitromax sidedress applications. Contact your Hintzsche representative if you are interested in learning more about these tests.

Rick Griesbach
Hz/PRA Agronomist
5/5/09

A Hintzsche customer bought a 20/20 Seed Sense Planter Monitor this spring. He started planting on April 23rd and I helped to set up the planter for the current field conditions. After the first day of planting he gave me this summary of what he learned with the 20/20 Seed Sense Monitor. This planter is a 16 row JD 1760, with E set units, and precision tubes.

1. Down Pressure: There is a real balance to keep enough down pressure that the disc openers stay at depth, and not too much to cause compaction in the seed slot. With the wet conditions on the first day of planting, we took off all the pressure, and with full seed boxes we had plenty of down pressure.
2. Mud: Mud costs you money very quickly! After going through a wet spot, there was a clump of mud on the transmission wheel, which introduced vibration into the planter transmission causing $20/a yield loss with decreased spacing. The next time it happened, he stopped and cleaned the transmission wheel.
3. The Ride Sensor: This sensor measures how much the seed boxes are bouncing. When he planted through a clumpy spot in the field, the number of spacing errors jumped up on the monitor. In other words, when the boxes where bouncing, the seeds bounced more in the tube, causing the ideal spacing to be lost.
4. Planter Speed: His planter speed was correct at 4.8 to 5.0 MPH. When he bumped up a gear, the skips increased quickly.
5. Each Hybrid Plants Differently: The second hybrid our customer planted (DK 61-72) was a smaller seed, and he had to increase the speed to get better singulation (not planting doubles) until the ride sensor errors started to increase.

Summary
Items #4 and #5 above contradict each other, but the thing I was very excited to see was the ability to dial in the correct speed, for the seed, the ride, and today's planting conditions.
To quote this 20/20 farmer, "Last year I had a disaster in this field, but this year I am planting this same field adjusting my speed, down pressure and row cleaners to get the best possible stand. This 20/20 paid for itself already!"

Rick Griesbach
PRA Agronomist