Two years ago, in Central New York, Ken, a “grass-fed” organic dairy farmer, asked me two cropping questions as he was planning his growing season. He was considering no-till seeding Japanese millet into land where he had planted rye cover crop the previous two autumns. He asked me how would millet compare to sorghum as a dairy cow feed.

Crop Comments: Seed Catalogs Already?

I told him that to the best of my knowledge Japanese millet was not available in the brown mid-rib (BMR) version. Varieties with BMR traits have been bred, through natural (non-genetically engineered) selection, for increased fiber digestibility. Pearl millet does have a BMR version, but its seed costs about twice as much as that of Japanese millet.

I told him that the BMR version of a given forage variety typically supports milk production better than the non-BMR version. Since sorghum, sudangrass and their hybrids do have BMR options, they would support milk production better than Japanese millet. But millet works better for dry cows and heifers than the “higher octane” varieties.

Flattering millet is the fact that it is more forgiving of less-than-ideal soil fertility. A field with a 5.7 pH, low phosphorus and marginal drainage will support millet much better than it will sorghum, sudangrass and their hybrids. Some agronomists refer to all four of these crop classes as hot climate summer annuals (HCSAs). This makes sense because millets originally developed in the warmer, drier regions of China and India and the other three annuals originated in sub-Saharan Africa.

Regarding seeding no-till millet into rye stubble after harvesting first-cutting baleage or haylage, I cautioned that HCSAs demand a soil temperature of 65º. Corn accepts – or at least tolerates – 50º. That being the case, it’s advisable to give the attempting rye regrowth a light disking to fight off any threat of allelopathy (natural weed-killer traits). This is also where a soil thermometer proves very useful.

Ken’s second question was “What seed rate do you recommend for millet? I believe the recommended sorghum rate is 40 lbs./acre, but we’ve had better success with 75 lbs./acre. Should we double the millet seeding rate too?”

Answer: A millet seeding rate of 40 lbs./acre should be adequate, if fertility is on target and the seed is drilled. When broadcasting HCSA seeds, increase the seeding rate by 15% – 20%, then harrow in lightly to minimize birds showing up for supper.

Japanese millet seed is much smaller than the other HCSAs. Most folks get a good stand when covering four acres with three 50-lb. bags of millet seed. Again, if broadcasting seed, increase the seeding rate by 15% – 20% and harrow in lightly to fake out our feathered friends. Writing about HCSAs on this last Monday of January is like perusing seed catalogs on Groundhog Day. Some people think it makes spring come faster.

For more management pointers on feeding HCSAs, I checked out research conducted by Dr. Larry Chase, professor emeritus, Cornell Dairy Nutrition. Chase found that with proper balancing, BMR sorghum species can support the same milk production as corn silage. Work at the Miner Institute in Chazy, NY, on BMR sorghum-sudan hybrids also documented the same milk yield as corn silage, but with higher components and greater feed conversion efficiency.

BMR sorghum species (and BMR sorghum/sudan hybrids) offer numerous benefits when compared to corn. Sorghum is about $100/acre cheaper to grow, for just the seed cost. Genetic rootworm resistance in corn is failing and disease control requires expensive fungicides. Sorghum species eliminate rootworm threats against corn in the next rotation. And they’re immune to corn diseases and are deer-proof. Sorghum kills rootworm by secreting prussic acid (hydrogen cyanide), which is bad for cows but fatal to rootworms. But as sorghum plants mature, the edible above-ground portion becomes prussic-acid free – which is not the case with their roots.

Organic farmers find that corn requires multiple cultivations, leaving soil vulnerable to erosion. This form of tillage – critical for a successful unsprayed crop – is at the same time perennial crops must be harvested for best quality. Thus, haylage is often made late, severely limiting profit potential for the organic farm.

Optimum sorghum planting is in drilled narrow rows (7 – 14 inches); replicated research documented 18% higher yields compared to 30-inch rows. Narrow rows quickly canopy to prevent erosion and shade out weeds, maximizing sunlight interception in short seasons.

Research done at the Miner Institute shows that sorghum/sudan’s rapid emergence and dense stands empower growers to utilize stale seedbeds so as to grow less corn for silage on organic farms. Less corn means less row cultivation for weed control. Thus, more organic farms have switched from corn to BMR sorghum/sudan as their energy forage. More and more conventional (non-organic) farmers are moving toward HCSAs, away from corn, for the reasons just stated.

Research supported by New York Farm Viability Institute examined various harvest stages of BMR sorghum. Results were analyzed by Chase using the Cornell Net Carbohydrate & Protein Systems model. Researchers observed that for seeded-type sorghum the milk potential increased from the boot stage as the fertilized seed heads began filling. The milk potential decreased – in comparing parts of the seed head – as they went from the tip of the seed head, just starting soft dough, to soft dough halfway down the head. This is because at the soft dough stage there are more significant decreases in fiber digestibility for the whole plant, where a lot of energy is stored. This in turn is compounded by the loss of energy in hard, indigestible seeds. Thus, Chase contends that waiting for mature grain can decrease milk production.

Looking back, we’ve seen that in the Northeast both 2023 and 2024 were particularly good years for growing HCSAs because there were so many days in our region with temperatures peaking in the 90s. Corn does not benefit from growing degree days associated with temperatures exceeding 85º. But sorghum has been shown to keep performing when heat pushed 105º.