Agronomy
I had a great week with clients reviewing technology purchases, openers, herbicide plans and picking up seed samples. Don’t forget to have your seed tested! Most clients, myself included, booked in some sweet deals on in-crop herbicides with an average cost in wheat and barley of $21 to $23 acre using premium products. The early book deadline for Syngenta, Bayer and Dow grassy herbicides is February 15, so that’s today. There are great deals to be had so don’t delay!
This week we’ll look an awesome system developed to improve maturity, yield and seedling emergence in heavy clay soils. Next, we’ll take a look at new way to squeeze our more acres per fill using a combination of urea and NH3.
Dramatically boosting seedling emergence in heavy clay soils is possible
Achieving fast and even emergence in heavy clay, high magnesium soils is often a challenge. These soils have a habit of staying cold and wet in the spring which slows root growth and nutrient uptake, namely phosphorus. Also, the tilth of the soil is often lumpy which leads to uneven seeding depth. If the soil is too wet or too dry, the soil flow over the openers can be uneven and leave strips of uncovered seeds lying on the surface. Those who farm “heavy gumbo” know exactly what I’m talking about. Over the last four years, my client Tony Pliva and I have successfully tweaked his seeding system to address these issues head on.
Tony farms heavy clay soils (clay>50%) with magnesium levels between 25% and 36% on a base saturation level. Soil aggregates start to break down and lose their structure when magnesium levels reach above 20% and the issues I described above start to pop up. Over the last few years, we’ve made a few modifications to the opener style, seed and fertilizer placement and seeding direction. The combination of all these changes has dramatically improved seeding depth, emergence and seedling mortality and maturity.
To begin, we switched Tony’s opener to a Dutch 1.75-inch low draft gumbo side band opener. The key to addressing poor soil flow is to reduce the amount of soil your disturbing. This opener is just 2.5 inches wide from side to side and has a closed bottom which reduces plugging issues often found in clay soil. The clay soil will peel like an orange and drive straight up the seed and fertilizer openings and plug off runs. This gumbo opener has done well to address the plugging issue. Also, the right and left sideband openers are pointed toward the middle of the drill which reduces plugging on tight corners as well. Normally, the wings of the openers point outward.
Next, the seed and fertilizer tubes were reversed to send seed down the fertilizer tube and fertilizer down the seed tube. Common practice is to sideband your seed and place fertilizer straight down the middle. The problem with side banding seed is the uneven seedbed created by the wing of the opener. The opener tends to lift large lumps of soil and place seed in an area of high variability. For example, look at the picture below that shows Tony’s wheat emerging. Notice the smooth finish where the seed is placed and the large clods of soil to the side where the fertilizer is placed. Normally, a sideband opener would place seeds into that cloddy mess where seeding depth can vary by 4 inches!
Now, in an effort to maximize phosphorus uptake efficiency and avoid stranding phosphorus above the seed row, we apply nitrogen and phosphorus separately and place all the phosphorus in the seed row. Most double shoot systems place 30% of the fertilizer blend with the seed and 70% down the fertilizer tube. This is inefficient and doesn’t provide proper phosphate granule distribution. Roots can only access phosphate granules that are within 2mm of the seed. Placing 60 lbs of 11-52-0-0 in a narrow furrow on 10 inch spacing gives us the phosphate granular distribution we’re looking for so every seed has access to early phosphate nutrition.
Last, we’ve started to inter-row seed in 2010 and leave taller standing stubble. Tony created his seeding direction in 2009 and followed up in 2010 with his first year of inter-row seeding using JD Starfire 2 GPS. This has given him even greater germination and emergence because 90% of the time he’s seeding into soil and not a mix mash of soil and stubble. Also, cutting the stubble taller puts less residue on the ground, which allows the soil to warm up faster in the spring. Covering the soil with a thick mat of blond residue is an emergence killer and leads to variability in soil temperatures across the field.
In the end, Tony’s germination and emergence has increased by 10% in the last few years simply by tweaking openers, seed and fertilizer placement and inter-row seeding. On his farm with his soil type, a 20% seedling mortality rate was common and now we’re down to just 10%. That improvement has not only led to higher yields and faster maturity, we’re saving on seed costs. In 2009 and 2010, we achieved our target plant stand density in wheat of 30 plants per ft2 using 10% less seed. Tony saved $6,000 in 2010 on seed and seed treatment costs alone.
If you farm heavy clay soils, give Tony’s set up some thought and think about what you could do with your own. We’re very satisfied with the results. SL
Maximize seeded acres using NH3 and dry fertilizer
There are a growing number of one-pass NH3 users in my area including clients. As you can imagine, the seeding efficiency with NH3 is much greater, in fact 1.75 times greater than straight dry fertilizer. Most one-pass NH3 users apply seed and P-K-S blends through the tow between air tank and apply all the nitrogen with the tow behind anhydrous tank. Depending on the set up, one product runs out well before the others which increases down time at seeding.
Clients Doug and Mike Miller and I figured out that with their system, they could gain another 10 acres per fill if they added urea to the blend instead of relying on NH3 as the sole nitrogen source. The Millers operate a 70 ft NH SD 550 with a 430 bushel tow between Flexicoil tank and 2,000 US gallon tow behind NH3 tank. On a typical wheat blend with seed in the front and middle tank and a fertilizer blend of 90 lbs/ac in the back tank plus 80 lbs N as NH3, they could achieve roughly 95 acres per fill. This was good but the NH3 would run out before the seed and dry fertilizer blend.
To calculate the number of acres per fill so that all tanks would run out at the same time, we worked back from the seed tanks. The seed tanks specifically in wheat require a high seeding rate and require two of the three tanks. From there we calculated the amount of product we needed to meet our nutrient goals and product rates. Here’s the math on how it was done for a target of 80 lbs N:
New system
2,000 gal/US/tank × 90% × 5.15 lbs/gal/NH3 x 82% N = 7,601 lbs/N/tank
Flexi-coil 430 bushel tank capacity: (8,094 lbs back + 5,814 lbs middle) ÷ 130 lb/wheat/ac = 106 ac/fill
Dry fert blend: 10,602 lbs front ÷ 106 ac/fill = 100 lb/ac (new 10-30-20-0 blend)
2,000 gal/US NH3 tank: 7,601 lbs/N/fill ÷ 106 ac/fill = 71 lbs/N/ac
Old system
2,000 gal/US/tank × 90% × 5.15 lbs/gal/NH3 × 82% N = 7,601 lbs/N/tank
Flexi-coil 430 bushel tank capacity: (8,094 lbs back + 5,814 lbs middle) ÷ 130 lb/wheat/ac = 106 ac/fill
Dry fert blend: 10,602 lbs front ÷ 90 lbs/dry fert blend/ac (old 0-30-20-0 blend) = 117 ac/fill
2,000 gal/US NH3 tank: 7,601 lbs/N/fill ÷ 80 lbs/N/ac = 95 ac/tank
In this scenario, we increased the nitrogen content in the dry fertilizer blend by 10 lbs/N/ac using a urea blend of 10-30-20-0 at 100 lbs/ac. This little tweak dropped the NH3 required and added another 10 acres per fill. With an average of 4 fills per day, they were able to seed an extra 40 acres each day, which is roughly one more hour spent seeding per day rather than filling. The dry fertilizer blend and NH3 combo we designed for canola is better at 98 acres per fill, even with a 110 lb/N/ac fertilizer rate! I the love efficiencies we’ve made on this farm and it just goes to show what a little out of the box thinking can do. SL
