New York Department of Parks and Recreation workers load Christmas trees into a mulch machine for use in compost and landscaping.

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Composting and Crop Rotation

Organic farming methods emphasize the use of renewable resources and conservation of soil and water. But this isn't a new idea, in the United States or worldwide. The term "organic farming" can be traced back to 1940, when Lord Northbourne, an agronomist, wrote about the concept of a farm as a living entity. In his book, "Look to the Land," Northbourne posits that we're all connected to each other, to our food and to our soil.

It all starts with good soil. The right mix of soil leads to healthier crops and animals, reduces their susceptibility to disease, and increases the overall productivity of the farm. Common techniques used by organic farmers to manage soil quality -- which involves not just the soil itself but also water, weeds, disease and pests -- include the use of animal manure, compost, cover crops, green manures and crop rotation.

Compost is organic material used with success in both home gardens and farms. It is made of decaying and decayed organic wastes and is spread on garden beds and organically farmed fields. Examples include:

  • Yard trimmings -- wood chips, grass clippings and leaves
  • Food waste -- coffee grounds, tea bags, and fruits and vegetables
  • Manures -- poultry, cow and horse

Using compost can encourage beneficial bacteria and fungi to grow, helping to create nutrient-rich, moist soil while also eliminating or reducing the need for chemical fertilizers.

Green manures and cover crops also improve soil quality. Plants are grown specifically to benefit the soil and the main crops on the farm -- farmers choose from a variety of cover crop plants depending on the needs of their fields.

Cover crops in general are used to protect the soil's surface from water and wind erosion, help maintain soil structure, and help maintain the level of organic matter of the soil, all of which keeps soil healthy. Green manure is a type of cover crop grown specifically to add nutrients back into the soil; manure is plowed together with the soil, positively increasing the soil's organic matter.

Cover crops are also used in place of conventional pesticides to keep weeds at bay and as a distraction to pests. Have you ever noticed that weeds always seem to take over a bare patch of your lawn? They flourish where no other plants are growing in their way. Cover crops take up space where weeds would love to make their home. The idea behind using cover crops in pest control is to both lure beneficial pests, such as ladybugs, to the field all year round and to deter unwanted pests from the main crops by offering an attractive and tasty alternative.

Crop rotations are also part of the strategy organic farmers use to help sustain soil fertility. For example, this year an organic farmer may grow wheat on a field, graze sheep on that field next, and plan to plant a cover crop of clover the year after. When the same crop is grown on the same land year after year, known as mono-cropping, the soil can become depleted of nutrients it needs to stay healthy. Variety here really is the spice of life.

There is also a variety of sustainable and organic management techniques used in raising livestock, depending on the types of animals on the farm.

In the next section, we'll look at genetically modified crops and why many countries refuse to grow them.