For a long time, in the past, the human species could get food only by hunting, fishing and harvesting grains, fruits and roots.
But about ten thousand years ago, our species also began to plant vegetables and raise the animals that serve as their food. It was the starting point for the development of agriculture.
With population growth and the need to produce more and more food, the original vegetation of forests and other ecosystems was being destroyed to make way for growing edible plants and raising animals. Today, deforestation is done with machines (tractors and saws) or with fire - it is the so-called burned, which cause a number of problems.
Of all the emerged (off-water) lands that make up the continents and islands of our planet, only about 10 percent is cultivable.
Far too often, agricultural activity is done improperly due to lack of knowledge or lack of resources and equipment. As a result, after a few years of production, soil nutrients are depleted and plants no longer grow.
Depending on the type of soil and the type of planting, some care should be taken with the land and certain procedures as we will see below.
Agriculture for food production to be sustainable in relation to the environment:
- should not cause harm to the environment;
- must not release toxic or harmful substances into the atmosphere, surface water or groundwater;
- must preserve and restore soil fertility, preventing erosion;
- You should use water to allow water supplies to recharge and prevent them from depleting.
Producing food also implies maintaining a diversity of crops so as not to deplete the soil and to use biological pest control when necessary, but with care to avoid contamination of the environment with chemicals that may accumulate.
Thus sustainable agriculture facilitates the local economy and preserves the health of the soil and the beings living in it.
When the soil does not have the conditions necessary for agriculture or when it is desired to improve its conditions, some care should be taken, such as fertilization, crop rotation, soil tillage, irrigation and drainage.
Fertilizing means enriching the soil with nutrient elements when it is deficient in minerals. For this, fertilizers are used, substances capable of fertilizing the soil.
Fertilizers can be organic (eg manure, bone meal, leaves, buried branches) or minerals which are inorganic (eg chemicals are applied such as sodium nitrate, a type of salt).
There is also green manure. Sometimes pulses are also used as fertilizers. When they grow they are cut and buried in the soil, enriching them with nitrates.
Crop rotation consists of alternating the planting of legumes with other plant varieties in the same location. In this way, the legumes, by association with bacteria that live in their roots, return to the place nutrients used by other plants, avoiding soil depletion.
Plowing the soil is another precaution to be taken so that the soil is not compacted, "punched".
Revolving the soil, in addition to aerating, facilitates soil permeability, allowing plant roots to penetrate the soil and bringing the existing humus to the surface.
Earthworms - Plows of Nature
The worms do a real plow work on the ground. As they move, they open tunnels and swallow part of the displaced earth, removing their food from there.
These tunnels, also called galleries, increase the porosity of the soil, so air circulation and water infiltration intensify.
Their feces contribute to the formation of humus, a very important organic matter for soil fertility, facilitating the development of decomposing or nitrogen fixing microorganisms.
The earthworm is the creation of worms in special tanks for commercial purposes. Earthworms are sold for bait, but the humus they produce is marketed as fertilizer for agriculture, gardening and so on.
Irrigation and Drainage
Irrigating and draining are some of the precautions that must be taken to maintain the required moisture level of the soil and to ensure that it remains fertile.
With irrigation, water reaches very dry regions or areas. With drainage, excess water is removed from the soil, allowing it to be aerated. As pores increase, air passages are created between soil particles.