Hemp crop 4

CULTIVATION

FIBER PRODUCTION

Fiber hemp grows best in well drained soil that doesn't crust and that
holds moisture within two or three inches of the surface. (154) Illinois
experts recommend silt loams and clay loams. (155) Iowa experts emphasize
good drainage, (156) noting that soggy soil produces weak fiber. (157) A
USDA agronomist declared Missouri's soil and climate "favorable" for
commercial hemp. (158) In the 1940's , northwest and southeast Missouri
were considered the best areas in the state for commercial hemp production.
(159) An acre that produces 75-80 bushels of corn can produce 2.5-3.0
tons of hemp, (160) but land that produces slightly lower corn yields may
produce far lower hemp yields. (161) Fertility is crucial to hemp yield.

Although nitrogen appears unimportant to growth of wild hemp (162),
good nitrogen supply improves yields of cultivated stalk. Commercial
nitrogen fertilizer works, and so does crop rotation. (163) Planting
hemp after alfalfa or clover works well, planting after soybeans helps to a
lesser extent. (164) Phosphorus and potassium can be helpful, and manure
is universally recommended. (165) Authorities note, however, that
fertilizers may increase yield of stalk but decrease yield and quality of
fiber from the stalk, (166) thus fertilizer application requires
knowledgeable judgment. Although hemp crops remove quite a bit of
nutrient, (167) hemp sheds leaves that return nutrients to the field, and
upper leaves remaining on stalks drop to the ground as part of the field
"retting" process described below. (168) In field retting the soil also
recovers about 20% (by weight) of organic material from stalks, and
farmers can plow stubble under. (169) Hemp's net extraction from soil
fertility is thereby less than many other crops (170) and is considered
comparable to corn. (171) Corn, incidentally, does well when planted
after hemp. (172) During the 1970's in France winter wheat commonly
followed hemp. (173) French growers find that hemp clears weeds and
cereal parasites from wheat fields, and the deep hemp roots help with
tilling. (174) Hemp crops are noted for improving physical condition of
soil. (175) Indeed, hemp has been recommended as a crop for soil building
purposes. (176) U. S. hemp production fell after World War II because
planted acreage fell, not because soil fertility declined. (177)

Fields can be plowed in fall or spring, though some authorities
recommend fall. Hemp thrives in the type of seedbed prepared for alfalfa.
(178) Seed can be broadcast or planted by seed drill no deeper than one
inch; drilling improves yield. (179) Seed is about the size of wheat, 44
pounds to the bushel, and 33-55 pounds per acre are recommended for fiber
crops. (180) Higher seeding rates don't increase the yield of stalks per
acre, but can increase yield of fiber from stalks. (181) Experiments
suggest that treatment with seed disinfectants have small or zero effect on
yield. (182) In the Midwest the best time to plant hemp is after oats and
before corn. (183) The first week of May may be ideal around Ames, Iowa.
(184) Growing season is 120 days.

Hemp grows quickly and reaches heights of 5 to 15 feet; for fiber
production, height of 6 to 8 feet and stalk thickness of 0.25 inch is
ideal. (185) Fiber hemp is planted in thick stands (20 or more plants
per square foot) that smother weeds. Few diseases or pests trouble crops.
Once seedlings appear, farmers rarely must do anything until harvest.
Hard rain is unlikely to lodge hemp, but strong hail can damage crops (by
destroying leaves and thereby harming plant growth). (186) Fiber hemp
needs ample moisture, and drought harms crops; a climate with at least 30
inches of annual rainfall is recommended. (187) In the 1920's authorities
reported irrigation to be feasible. (188)

Traditionally in the United States, mills that contracted for crops
rented mechanized hemp harvesting equipment to farmers, relieving farmers
from the large up-front cash outlay that purchase of such equipment would
require. (189) In the 1940's equipment rental in the federal program was
$ 4 to $ 7 per harvested acre, deducted from crop payment by the mill
rather than paid up-front by the farmer. (190) Private mills had similar
arrangements with their growers. (191) Harvest starts in late August and
continues through September. American authorities recommend harvesting
while pollen sheds and before seeds form. (192) Before 1967 French
growers harvested after seed matured, but French practice now follows the
American one. (193)

If harvested stalks are stacked and stored in dry conditions they will
keep for years. They do not have to be processed right away. (194)

Normally, harvested fiber stalks must be "retted." In retting,
stalks are commonly left on the ground for weeks or months so weather may
start to decompose them, making it easier for breaking and scutching mills
to remove fiber from stalks. Field retting is sometimes called dew
retting. Heavy dew, "reasonably high" humidity , and intermittent rain
are important for field retting. (195) Stalks can also be retted
underwater in ponds or tanks. This method produces better fiber than field
retting, but in the 1940's American technology did not make water retting
economical in comparison with field retting. (196) Research at Iowa State
College established that controlled water retting could be accomplished in
36 hours. (197) The head of the federal hemp program declared in 1944,
"If a program of controlled retting can be developed, I am very confident
that there is no limit as to the tonnage that can be grown successfully and
profitably in this country." (198) One account from the 1970's noted a
Swedish water retting operation with capacity for 150 tons of stalk at any
given time, producing 33 tons of fiber per day. (199) Some work has been
done in processing unretted hemp. (200) Retting is universally considered
the hardest part of hemp farming, because shrewd judgment is needed to
determine when the crop is properly retted. Fiber yields from improperly
retted crops are inferior.

In the 1980's Canadian Hemp Industries Corporation demonstrated a
decorticator that stripped fiber from stalks upon harvest in the field
without retting. (201) Such technology eliminates the riskiest part of
raising hemp fiber crops, making them more economically viable than they
were in the 1940's.

After stalks are field retted, they are bound and shocked. These
steps typically occur at the peak of soybean and corn silo filling, and
require more labor than corn harvesting, but 1940's farm operations handled
the labor demand. (202) Until around World War I hemp farming was labor
intensive, but mechanical harvesters and mill machinery dramatically
reduced labor requirements. In the 1920's mechanized Wisconsin hemp
farmers were able to compete with cheap foreign labor. (203) In 1943 a
typical Illinois hemp farm required 19.4 man hours per acre for the season.
(204)

Farmers send bales of retted stalks to breaking mills.

As a general rule, the higher the yield of stalks per acre, the higher
the quality of fiber from that yield. (205)

SEED PRODUCTION

Although Missouri had large hemp fiber crops in the 1800's, the last
remnants of the state's hemp production in the 1940's supplied seed for
fiber growers. (206)

Climate and soil types recommended for fiber production are
essentially the same for seed production, although ample soil calcium is
emphasized for seed. (207)

Seed hemp is commonly planted in hills 4 or 5 feet apart, thinned to
3-5 young plants. (208) Plants become bushy.

With American varieties growing season for seed is at least 180 days.
(209) Traditional harvest method is to cut the plants by hand 8-24 inches
above the ground, and shock small bundles of them. After drying (a process
taking a few days to 3 weeks) each shock is put on a tarpaulin and seeds
are manually beaten off with sticks. "While this seems a rather crude way
of collecting the seed, it is doubtless the most economical and practical
method that may be devised. The seed falls so readily from the dry hemp
stalks that it would be impossible to move them without a very great loss.
Furthermore, it would be very difficult to handle plants 10 to 14 feet
high, with rigid branches 3 to 6 feet in length, so as to feed them to any
kind of thrashing machine." (210) Seed for new crops is sent to a
cleaning mill. Seed for oil is shipped to a crusher.

Although traditional U. S. cultivation practice requires farmers to
choose between fiber or seed production, foreign seed growers have
harvested seed stalks for low grade fiber. (211) Before the mid-1960's
such practice was also traditional among fiber growers in France, where
fiber is used for paper rather than textiles, and can therefore be of lower
quality. Seed harvested this way is used for animal feed and for planting
new crops. (212) American experience indicates that such seed is poor for
new crops, however. (213)

SCALE OF OPERATIONS

In the 1940's each hemp breaking mill constructed by the federal
government cost $ 300,000 and required about 4,000 acres of crops for an
ideal level of operation. (214) (Breaking mills are the first step of the
fiber manufacturing process, and are a different operation from spinning
mills that turn fiber into thread and yarn.) Federal authorities expected
mill profits to recoup construction costs in five years. (215) Farmers
apparently raised hemp as one element of a diversified production
agriculture operation; Illinois hemp farmers planted an average of 30 acres
each. (216) Reputedly the country's largest crop in 1944 was 270 acres on
an Iowa farm. (217) Transportation factors, heavily influenced by war
rationing of rubber and fuel, generally required crops to be grown within a
15 mile radius of the government breaking mill in order to be economical.
(218)

We don't know whether such factors would constrain hemp production
today. Even by 1944 the head of the federal hemp program believed that
improved farm efficiency might soon allow government mills to run from the
production of 3,000 acres instead of 4,000. (219) Private mills
constructed to different specifications might serve different size
acreages. For example, around 1917 Wisconsin mills needed 300-750 acres of
ideal operation. (220) In 1924 a California authority said 50 acres would
serve. (221) In 1937 the Amhempco Corporation mill in Illinois could
handle 15,000 acres but did not run at capacity. (222) In 1978 a French
breaking mill serviced 6,000 acres grown by 93 farmers. (223) Before
World War II some retted hemp was processed by portable breaking machinery
in the field, (224) but the mills seem to be standard practice.

Mechanized harvesting equipment is another factor. If not provided by
a mill, equipment must be purchased by farmers, singly or in cooperation.
In the 1920's each 100 acres needed a mower-spreader and a binder in order
to harvest at the proper time. (225) Harvesting machinery for other crops
can be adapted to hemp.

Factors governing fiber economics may be irrelevant to oil seed
crushers. For instance, in the 1930's they shipped hemp seed by railroad
boxcar, (226) so obviously seed growers did not have to be located within
15 miles of crushing factories. Indeed in the mid-1930's crushers annually
imported tens of thousands of tons of seed, (227) mostly from Manchuria.
(228)

Breaking mills are a source of employment for rural towns. (229)
Each government mill in the mid-1940's hired 125 to 140 hands. (230) In
the latter 1940's a mill producing 10,000 pounds of fiber in 8 hours
employed 80 persons. (231)

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