Crop Comments: Crop guru pushes hot climate summer annuals

“Most corn is in the ground. Fields that were weather-caused fallow can still produce a very high-quality forage from sorghum. Sorghum is planted after corn because the soil has to be warmer than for corn for rapid germination. Thus, planting after early winter triticale and haylage harvest gets those jobs out of the way and gives time for the soil to warm.”

So wrote Certified Crop Advisor Tom Kilcer in his recent monthly newsletter (advancedagsys.com).

At his demonstration fields in Valatie, NY, Kilcer has planted into warm soil (with rain following immediately after) and the sorghum was all up in two days. This hot climate summer annual (HCSA) originates in sub-Saharan Africa. It needs to stay warm.

Kilcer pointed out what he considered an economic no-brainer. With many modern corn hybrids’ seed costing as much as $180/acre, sorghum shines with its correct population costing $20/acre. Sorghum’s prussic acid residues kill corn rootworms. Deer pressure lessens, as they hide in the crop and come out to eat the neighbor’s corn. It does not get corn diseases, but thus far we lack fungicide sprays for forage sorghum.

Drilling in narrow rows shades the ground sooner, encouraging larger stalk size, providing both standability and digestible nutrition storage. His target is 60,000 seeds/ acre in six- to eight-inch rows. Fifteen-inch rows could do, but the plants are more crowded in the row. He does not recommend planting in 30-inch rows (occasionally recommended for corn silage). In the wider rows, the crowded plants are susceptible to pre-harvest lodging.

Kilcer stressed that planting a higher rate of seeds/acre does not increase yield but does increase lodging. Smaller stems have a higher percent rind that is mostly indigestible lignin. Milk/ton was maximized in their replicated trials at slightly above 60,000 seeds/acre in 7.5-inch row planted with an air drill.

Quoting Kilcer again: “Don’t let a pushy seed salesperson tell you different. You and your crop will pay the price otherwise.”

There are several ways to achieve the above. The best may be planting with an air drill directly into 7.5-inch rows. According to Kilcer, each seed is index-planted so it produces uniform stands. In both triticale and forage sorghum, placing each seed precisely (like with corn) maximizes yield and minimizes lodging. Most drills are a controlled dump, lacking this degree of accuracy. The clump of crowded seed causes an increasing circle of lodging, knocking over plants next to the clump. Adding insult to injury, cranking the drill down to 4 lbs. seed/acre, like most varieties need to be planted at, results in planting non-viable, sorghum flour.

Adding something like cracked corn at the same rate as the sorghum, and then planting double the pounds/acre, helps get around this, but having an accurately indexed drill planting each seed individually is best. An alternative is to take a 15-inch corn planter and put in Milo plates and set it for 30,000 seeds/acre. Set the draw bar four inches to one side. Planting up the field, then coming on the same tire tracks, will make two rows that total 60,000 seeds/acre on eight-inch rows with each seed single-planted.

Kilcer stressed the need to adjust both the forward and back set of planter units so they are planting the right amount.

Planting sorghum after triticale harvest works well, following three to six tons of very high-quality dry matter triticale silage. After the haylage harvest, it’s go time, growing season-wise. Soil is then warm, so the sorghum can jump out of the ground. But, quoting Kilcer again, “Do not no-till sorghum into triticale stubble like we do corn, as allelopathy will wipe out or severely decimate the sorghum stand. The allelopathic compounds from the winter grain are in the top inch that affect the sorghum germination. Working the top inch will break down the allelopathy and eliminate that problem. Some farms apply manure and immediately work the top inch to capture the nitrogen while breaking down allelopathy, and then plant a day or so later, after the resulting ammonia reacts with the soil.”

However, a major sorghum problem is grain present in silage systems. Kernels quickly get as hard as a shotgun shot, going through the animal undigested. Corn processors don’t solve this problem. Ag engineers are working on developing other processors, but Kilcer and his cohort takes a different approach: Male sterile (a trait producing no seed) produces crops with no hard seeds and low starch but very high water-soluble carbohydrates (sugar) of 28% – 30% (compared to corn’s 2% – 4% sugar). The major savings are canceled if the crop does not produce the same milk as corn silage.

The surprise was a university trial where corn silage was partially removed from the ration and brown midrib sterile sorghum (with delayed harvest to increase sugar levels) replaced the corn. Result: Milk production increased 8 lbs./cow, and components increased significantly. Male-sterile sorghum was a superior crop to corn silage for milk production!

Back in 2012, I learned of drought-related research Kilcer was conducting at Valatie. He invited me to tour his demonstration plots. In mid-July that year, I learned that his location had received only a half-inch of rainfall from June 1 to July 15. His corn stands had all shriveled up and died. His plots of sorghum, sorghum- sudangrass, millets and milo (all HCSAs) were unfazed by serious water shortage. If they could talk, they would have asked, “What drought?”

University of Texas research has shown that these crops survive on half the water corn requires.

by Paris Reidhead