As we celebrate Tu Bishvat, the holiday of the trees, we need to take a critical look at our cultivation and production methods. Whereas tree crops represent one of the most sustainable forms of agriculture, they are outnumbered by modern agriculture's megacrops, which badly damage the earth. The latter waste nutrients, pollute the water and allow topsoil to be blown away, while the chemicals they are sprayed with contaminate food. And modern agriculture uses more energy than it produces in the form of food. Amid a global energy crisis and world hunger, we cannot afford such carelessness.
Perennial crops are inherently more sustainable than the annual crops of modern agriculture, which need to be replanted each year. Sustainable agriculture can help heal the earth - if we recognize its value in boosting the quality of our food and land.
Erosion is the enemy of both agriculture and civilization, according to J. Russell Smith, author of "Tree Crops," a classic text on arboreal agriculture. Smith took a series of trips in the 1930s to the Mediterranean, Far East and Middle East to study land use. He was appalled by the vast stretches of destroyed and depleted land he encountered: "Forest - field - plow - desert. That is the cycle of the hills under most plow agricultures." Between the water erosion on hilly and sloping lands and the wind erosion on flat plains, the world's fertile topsoil continues to drift away or be washed away. So it is no exaggeration to say that topsoil erosion is as big a threat as climate change, a problem not as visible as the coming oil shortage but a far greater danger to humankind.
The world's population is bigger than ever, and all humanity needs food. But depending, for our food, on a system that systematically ruins the land simply means that sooner or later we will not be able to produce food for ourselves.
The megacrops (the most important commercial crops) of the 20th century are all weak competitors - they have to be planted in environments where other plants have been eliminated. Grains, for instance, are grown on bare fields with every weed sprout sprayed or harrowed out of existence. Rice is cultivated in flooded, intensively weeded paddies; soybean and rapeseed are grown in fields stricken by chemicals; and corn is grown in huge blocs as big as small countries, where no other living thing is allowed to survive.
A terrible ecological price is paid for this kind of cultivation, all over the world. Communities wither, wildlife disappears, and the land dies. Unfortunately, almost every modern crop is cultivated this way.
That is, every kind of crop except trees. Their bounty of fruits, nuts, fibers or pods is a blessing to the earth, and their cultivation is not inherently damaging. Trees do not need annual plowing and can be fertilized with organic materials like compost and mulch. Diverse orchards can be kept pest free with sensible strategies.
Just about every damaging factor in modern agriculture is absent from arboreal cultivation. Tree crops can actually yield significantly more food, including carbohydrates and animal feed. Once upon a time, in ancient Greece and among Native Americans in California, for example, the main source of bread was oak trees. The bottom line is that there are many alternative options that need to be explored.
Moreover, the ecological benefits of trees are profound: They make food and oxygen, and manufacture topsoil by breaking up rocks in the subsoil and releasing minerals later stored in fruit, seeds and leaves. Their roots stabilize the soil and protect it - creating microorganisms and insect homes. Trees stop erosion, store water and are magnets for rain. A mature deciduous tree may give off 500 liters of water from its approximately six acres of surface area on a warm summer day. The cool air under the trees, drawn upward as rain clouds glide over, often leads to rain. The trees then absorb water through their leaves, and the raindrops settle among their roots.
With all the benefits of arboreal agriculture, why then are plowed crops the most prevalent form of cultivation? Perhaps modern agriculture has narrowed its sights to things that can be bred quickly and provide produce quickly - things that can be done in an instant. Agriculture is focused on quick annual crops.
On this Tu Bishvat, we should remember trees' environmental benefits in mitigating and stabilizing the climate: The air and the earth are several degrees cooler under a tree in hot climates and several degrees warmer in a cold one. In addition to acting as the world's lungs, trees are the earth's air conditioners. Deforestation, something of a throwaway line when global climate change is discussed, is most likely one of its main causes. Public debate over climate change must address alternative cultivation methods and embrace arboreal agriculture as a key solution.
Dr. Elaine Solowey is director of the Center for Sustainable Agriculture at the Arava Institute for Environmental Studies.
