Fiber Crops. Seed-Borne Fibers. Leaf (or Hard) Fibers

Fiber crops of nonwoody plants have been important in world history for the products they have provided and for their economic value. These plants have produced fiber for fabrics, cordage for rope and twine, and pulp for paper for thousands of years in many places around the world (woody fiber plants, such as papyrus and trees, also have yielded pulp for paper).

Seed-Borne Fibers. Plants that have hairs attached to their seeds or the inner walls of their fruit are valuable fiber crops. Commercially important in this category are cotton and kapok (the silky hairs around ceiba tree seeds used as filler for mattresses and life preservers).

Strains of cotton, originating in Asia, Africa, and on the tropical west coast of the Americas, were domesticated four thousand years ago but came into high demand when Great Britain's textile industry boomed in the late eighteenth century. Thus European planters exploited cotton where it thrives in warm climates in India, Egypt, Brazil, Mexico, and the U.S. South, among other places.

The U.S. South became a "cotton kingdom" from South Carolina to Texas and by 1820 was producing 500 million bales a year. The cotton plantations caused severe erosion (depleting 50 percent of the region's topsoil), spawned insect infestations, and required slave labor imported from Africa. When resources were depleted in one place, the growers simply converted more land to cotton fields on a westward-moving grid across the Deep South.

Today California, Texas, and Arizona are the largest U.S. cotton producers. Internationally, China, the United States, Russia, India, Pakistan, Turkey, and Egypt are the leading producers. Brazil, Mexico, and Central America also raise great quantities of the versatile fiber, which is used to make cool, comfortable clothing.

Stem and Bark (or Soft) Fibers. Some of the world's most commercially valuable plants are grown for stem and bark (or soft) fibers. An example is hemp, among the oldest cultivated plants known to humankind—cultivated as early as 2800 BCE in China.

From there it spread to Europe, especially Russia, and was introduced to other temperate zones. In the United States hemp varieties grew particularly well in Kentucky and Wisconsin. Hemp fiber has been used to make paper (including that on which the Declaration of Independence was written), cloth, and most importantly for the manufacture of rope. Thus its military importance to supply rope to ships has been great. During World War II U.S. farmers raised 54,431 metric tons of hemp a year for the war effort.

The plant, growing over 3 meters in height, can drain the soil of nutrients and requires a great deal of organic matter. It also is prone to soil-borne fungi and various diseases, but crop rotation usually averts those problems. There is little evidence of hemp causing ecological degradation. On the contrary, proponents claim it is among the best crops to cultivate in temperate climates.

Hemp also grows well in the tropics, but the warmer, moister climate stimulates the plant's production of the resinous narcotic tetrahydracannibinol (THC), which produces psychoactive qualities when prepared as hashish, ganja, or marijuana (made from the dried flowering tops of the female plants). Thus raising hemp is illegal in some nations. In the United States, Congress passed the Marijuana Tax Act in 1937 to impose high taxes and strict guidelines on the crop.

Some scholars argue that Nezo York journal publisher William Randolph Hearst was behind the act's passage so that hemp would not compete against his own forest and pulp interests. Today hemp is raised commercially throughout the world (except in the United States, where the tax still discourages its production). The leading hemp countries are Russia, China, Chile, Italy, Poland, Serbia and Montenegro (Yugoslavia), Hungary, and Romania. Canada legalized hemp production in 1999.

Other soft-fiber crops include jute, kenaf, ramie, and flax. After cotton, jute is the second-most economically important fiber crop in the world. It is grown primarily in its native India and Bangladesh and in China, Nepal, and Brazil. The fiber is used to make rope and coarse fabrics, Kenaf, also from India, is similar to jute and is gaining in popularity due to its resistance to drought and adaptability to diverse conditions. Its fibers are used to make paper and cordage products.

Ramie—one of the oldest and strongest of all vegetable fibers and used to make cloth, paper, yarn, curtains, and tapestries—is grown primarily in China and Japan but is becoming more popular in Europe and the Americas. Elax is the world's third-most-important fiber cash crop. The plant, used by the ancient Egyptians and mentioned in the Bible, produces a fine fiber that has been used for thousands of years to make linen, lace, and apparel fabric. Over 80 percent of the world's flax supply now comes from Russia, Belgium, Germany, Canada, and the United States are other producers, (A different variety of flax produces linseed oil.)

Leaf (or Hard) Fibers. Leaf (or hard) fiber crops include sisal, henequen, and abaca (Manila hemp), whose leaves are cut and retted (soaked) primarily to make rope and twine but also for hammocks and gunny sacks. Sisal and henequen are agave plants native to Mexico's Yucatan Peninsula, but sisal has been successfully introduced in Africa, Brazil, and the Caribbean Basin, Abaca is fiber from a relative of the banana plant that is native to the Philippines but that now thrives in India, Indonesia, and the Pacific islands.

Sisal and henequen were in high demand from 1890 to 1950, when the twine that their fiber produced was needed for a grain-harvesting implement called the "binder." The grain industry throughout the United States and Canada became dependent on this twine, causing an economic boom and an environmental transformation in Yucatan when hundreds of thousands of acres were converted to henequen plantations. And in North America the binder helped to expand the grain industry when demand for wheat during World War I was high.

So dependent was the grain industry on sisal twine that in 1915 (a record crop year for wheat) the United States sent gunboats to Mexico to secure shipment of the fiber when, during Mexico's revolution, an export/import blockade was imposed on Yucatan. The scenario represents the degree to which a double dependency emerged between different agricultural commodities, yet it all came to a close by 1950, when North American farmers switched to combine harvesters that did not require twine.

The henequen industry in Yucatan was left virtually paralyzed; attempts to find similar markets for the fiber failed, leaving the local economy in serious decline — a victim of nondiversified monocrop agriculture and dependence on foreign interests.

Today there are only remnants of the former henequen boom, with a small fiber industry producing burlap, mats, and twine. In an ecological twist, however, much of the former plantation landscape is reverting to its former Yucatan vegetation with renewed habitat for local wildlife. With the world forests dwindling at the beginning of the twenty-first century, fiber from crops like those mentioned here offer viable alternatives and will be much in demand.