Crop Comment: Moisture-miser millet

Early this month, the weather reporter on the Utica TV station announced that the official precipitation total for May was a little less than 0.5 inch. Normal rainfall for that location and period is about three inches. Throughout most of the Northeast this statistic is not unusual. Folks receiving more rain than that have been fortunate, and acknowledge that their water blessing has been sporadic: many of their neighbors were totally by-passed by heavenly spigots’ generosity. One farmer, whom I advise (about 15 miles north of my home) received one inch of fairly hard rain last Friday. Most of his cropland is in sod, and his fields in corn and soybean have healthy soils. So he experienced no visible soil loss — even on what the Soil and Water people call HEL (highly erodible land). From the same thunderstorm system, downtown Hartwick (my home) received about 0.01 inch of rain.

To date, June, in most Northeast locations, has been about as short-changed on rainfall as was May. Hay harvest reports commonly show 2020 first cuts totaling half of or less than 2019 first cuts. What made the ongoing moisture deficit hurt even more is the fact that winter 2019-2020 was less than generous with snowfall. This is an unofficial guess, but winter precipitation ran about half of normal (also about three inches per month). Another element undermining moisture security is the presence (or lack thereof) of abundant soil organic matter (OM). Classic USDA data shows that for every one percent loss of soil OM, the reservoir benefit has been reduced by about 16,000 gallons per acre (about three quarts per square foot). So it’s particularly important when moisture is so limiting to have abundant OM so as to hang onto what little rainfall growers receive. The increasingly common soy/corn non-rotation [absent fall cover crops (or winter forages)] slowly, but surely, dissipates soil OM. Those two crops lack the fibrous root systems so critical in forming OM.

Let’s tap into agronomic minds in academia. We learn from University of Texas researchers that when rainfall is deficient, a given quantity of precipitation supports twice as much forage dry matter growth from sorghum (and/or Sudangrass), as from whole plant corn forage. Also, from North Dakota State University (in a state which averages 17 inches annual rainfall) we learn from their agronomists that millets are even more efficient at converting water to forage dry matter. With the idea that millets need even less water than sorghum, I would recommend planting millet on sods with less than 4% OM. Plant sorghum or Sudangrass (or their hybrids) with soil OMs of 5-6%; hopefully the latter are available in BMR gene 6 hybrid varieties. With sod OMs exceeding 5%, I believe that the moisture reserve situation would be adequate to support short season silage corn hybrids. These may likely be on fields where first cut hay crops have already been harvested.

Further support for millets comes from Purdue University agronomists who say that millets can be grown in a wide range of environmental conditions, being better adapted than most crops to hot, dry regions. Because of their short growing season (usually 65-days), they fit in well in semi-arid regions at higher altitudes. Millets are some of the earliest crops to be cultivated, being a staple food in eastern Asia (China, India, Siberia), as well as Europe, and some parts of Africa during pre-recorded periods. All millets are blessed with the C-4 photosynthetic trait, but the most common millets, in the Northeast, are Japanese and Pearl.

Let’s refresh our understanding of the C-4 concept. Corn, sorghum, Sudangrass, their hybrids, millets, and even sugarcane are in the C-4 category. During photosynthesis, most plants create compounds using three-carbon units. But these last crops, just mentioned, perform their carbon-structuring function, using four-carbon modules. So botanists collectively group these plants as C-4s. The C-4 trait is a real advantage, particularly in areas where too much heat combines with too little water. In order for a plant to gather carbon atoms from the air, it opens its stoma (microcropic openings on the leaves). C-4 group members use their stoma to limit water loss and retain acquired carbon much more efficiently than C-3s. Of the C-4s, here’s the ranking in terms of moisture retainability: millets, sorghums, Sudangrasses, sugarcane and corn — in that order.

Some on-line research, drawn from India (the country which grows the most millet) reveals that millets can be grown on soils less than six inches deep. Thus that they do not require rich soils in order to survive, and fit in well in that country’s vast dry land regions. Quoting from one of the Indian websites, “Millet production is not dependent on the use of synthetic fertilizers (sic)… therefore (growers) use farmyard manures, and in recent times, household-produced bio-fertilizers, significantly reducing the huge burden of fertilizer subsidy borne by the government. Grown under traditional methods, no millet attracts any pest. Therefore, their need for pesticides is close to nil. Thus they are a great boon to the agricultural environment.” Very likely, sustainable farmers in the Northeast — particularly those growing millet — have a lot in common with their counterparts in ancient lands.

Millets also do well with excess moisture [unlike our present Northeast growing season (thus far)]. The most common millet grown in our region is Echinochloa frumentacea (Japanese millet). It has coarse leaves, growing as tall as five feet, depending on available moisture and fertility. The seed head is four to eight inches long, purplish in color, with awn-less seeds. Seed may be drilled (no deeper than one inch) or broadcast. Recommended seeding rate, when drilled, is 20#/ acre; when broadcast, bump up the rate to 25-30#/acre. When millet has headed out, harvest it for forage, because it is already done forming roughage dry matter. One more plus for all millets… should you want to graze aftermath regrowth, there’s no prussic acid. Most Northeast locations can plant millet up to July 15.

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