Top Crop Manager

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Sudangrass and sorghum generating interest

Alternatives offer some interesting aspects


November 13, 2007
By Top Crop Manager

Topics

36aGrowers looking for opportunity often try their hand at one or another cropping
alternatives. Some are hoping for a higher value return for their efforts, others
are hoping to improve their bottom line by reducing costs. It may even have
something to do with adding another crop in the rotation. Whatever the reason,
growers across Ontario are considering the economic and agronomic virtues of
forage sudangrass and grain sorghum. The two cropping alternatives are garnering
more attention from growers for different reasons.


In just a few years, forage sudangrass has attracted growers' attention for
its suitability as a forage crop, a cover crop and for its potential as a source
of lush and dense biomass, with a variety of possible uses. Its current acreage
in Ontario has reached a plateau of 10,000 acres. Grain sorghum has been cited
as a supplement for corn in the ethanol trade, as well as a source of seed for
specialty bird feed and a fledgling attempt to use it in livestock feed. Current
acreage levels for sorghum sit around the 2000 acre mark. A third alternative
is pearl millet, which is being promoted solely as a cover crop, however, its
suitability as a rotational crop lends itself more to the fruit and vegetable
sector.


Marv Eberle of Milo Pro has been working with Agriculture Environmental Renewal
Canada since 2005, promoting forage sudangrass and grain sorghum, in particular.
He believes there are considerable advantages to growing either crop, yet he
concedes both require firm commitments in order to make them viable.


Forage sudangrass has shown favourable results as a cover crop, with a data
set that places it ahead of red clover and rye. Dry matter yields for forage
sudan are 4400lb/ac versus 4000lb/ac for red clover and 3310lb/ac for rye. Although
N levels are slightly lower than red clover (115lb/ac versus 125lb/ac), its
overall nutrient value tops out at $93 per acre compared to $89 for red clover
and $58 for rye (see Table 1).

Table 1. Nutrient uptake of sudan cover crops.
Crop percent protein Dry matter yield (lb/ac) N (lb/ac) P2O5
(lb/ac)
K2O (lb/ac) Nutrient value ($/ac)**
Sudan 16 percent 4400 115 13 113 93
Cereal rye 16 percent 3310 84 10 53 58
Red clover 20 percent 4000 125 12 90 89
Biomass nutrients data from sudan hybrid, 50 days after
planting. Collected and summarized for one cut, at 40in plant height, in
seven inch rows.
** Sudan $93/ac value based on 456lb/ac of 25-3-25 at $450/t; Rye $58/ac
value based on 285lb/ac of 29-3.5-18.5 at $450/t; Red clover $89/ac value
based on 43lb/ac of 28.5-2.8-20.5 at $450/t.


"When seeded with good seed to soil contact and adequate moisture, sudan
is adaptable to all soils and is very aggressive, flourishing with the mid-summer
heat and humidity. It adds a lot of nutrient value back into the soil at plow-down
and while it's not going to reduce your fertilizer costs by a lot, it will help
you when you use your fertilizer dollars more wisely."


As a forage, Eberle recommends cutting plants at 36 to 48 inches, leaving six
inches of stubble to generate regrowth and encourage deeper root penetration
to help improve soil structure. It has the potential for two to four cuts per
season and is extremely frost sensitive, meaning quick die down in the fall
and no volunteers the following spring. "If we have growers looking at
growing a cover crop or replanting due to other calamities, be sure to check
the chemical label previously used for the original crop," explains Eberle.
"Unless glyphosate has been used as a stand-alone, there are many herbicides
that will injure the new crop."


On a rotation basis, Eberle has seen solid yields following corn, soybeans,
wheat or other forages.

Less yield and lower costs than corn

Although grain sorghum, also known as milo, has not captured the same amount
of attention as forage sudangrass, its potential is nonetheless impressive.
According to Mike Columbus, new crop development specialist with the Ontario
Ministry of Agriculture, Food and Rural Affairs in Simcoe, interest in grain
sorghum has varied as word of its yield and price relative to corn has come
to light. At a meeting in March 2007 to discuss sorghum and its potential, representatives
from Greenfield Ethanol in Chatham cited a price roughly $0.30 per bushel higher
than the CBoT futures price for corn based on incentives and a local basis.
The sorghum purchased by Greenfield will be shipped to its batch plant at Tiverton
for test runs.


Despite its higher price, Columbus reports yields are more similar to wheat,
in a range of 70bu/ac to 80bu/ac with some yields topping the 100bu/ac mark.
"But with corn and soybean prices the way they are now, it's harder for
sorghum to get going," concedes Columbus, adding that 2007 marks something
of a fresh start for grain sorghum, although there have been several attempts
in the past 20 years to bring it back to growers' fields. "But it's been
since 1994 that we've shown as much interest in getting it reintroduced here."


The good news from a revenue-cost perspective is that although yields are lower
than corn, so are the costs. Excluding land prices, the cost of production numbers
for corn can fall in a range of $350 to 450 per acre; for sorghum, the price
tag is less than $200 per acre after harvest.


Agronomically, the recommendation is for planting in late May, past the point
of where frost could do damage. It is important that harvesting be completed
around the first week of October. Sorghum does well in the same soils as corn
with loam soils seemingly the best. "It's also more drought tolerant than
corn, so it'll do better in sandy soils, as well," says Columbus.


"Right now, we're recommending growers plant sorghum in rows because as
of 2007, we have no herbicides that are registered for use on sorghum, so weed
control is one issue. The other issue is with birds feeding on the plants, if
they find the field."


Oddly enough, it is bird feed that represents another market for sorghum along
with a supplement in livestock feed. A pilot project underway at the University
of Guelph Ridgetown Campus is studying the feeding of distillers grain from
sorghum-based ethanol to livestock in order to determine its feed efficiency
relative to corn-based distillers grain. 


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