It is an organic agricultural system which focuses on maximum yields from the minimum area of land, while simultaneously improving the soil. The goal of the method is long term sustainability on a closed system basis. It has also been used successfully on small scale commercial farms (1). Whole farming systems give emphasis to diversity and offer both a sufficient amount and quality food which generates profit to buy other provisions. It further provides the family with a year-round supply of food and income together with a year-round source of employment.
The System
- In order to achieve greater productivity, the bio-intensive method uses double dug raised beds, intensive planting, and companion planting.
- In double digging, a 12 inch (305 mm) deep trench is dug across the width of the bed with a flat spade, and the soil from that first trench is set aside. The 12 inches (305 mm) below the trench are loosened with a spading fork.
- When the next trench is dug, that soil is dropped into the empty space of the first trench, and the lower layer is again loosened with a spading fork. This process is repeated along the full length of the bed. The final trench is filled with the soil that was removed from the first trench. The result is a bed that has been tilled to a depth of 24 inches (610 mm).
- When an entire bed has been double dug, the soil will have greater drainage and aeration, which allows the roots to grow much deeper and reach more nutrients. Despite the fact that no soil has been added, the bed is raised due to the aeration.
- Unworked soil should be double dug each season until the soil has attained good structure and long lasting aeration. During subsequent seasons, it can be single dug with a spading fork until compaction again becomes apparent. After double digging the first season, deep tilling during subsequent seasons can be quickly accomplished with a u-bar, particularly in the cases of larger mini farms or commercial farms (1).
The bio intensive method includes the raising of animals. A diet which incorporates animal products can be raised bio intensively, without graze. Although this uses the land less efficiently than a vegan diet raised bio intensively, it is more space efficient than typical methods of raising animals(1).
Factors Contributing To the Need for Urban Agriculture Since the world population is increasing urban quarters have turned out to be an essential new leading edge for food production. The city expansion and degradation contribute towards the crucial need for urban agricultural development. The economic and health problems resulting from malnutrition have caused great concern amongst planners and decision-makers. A case study of an Ethiopian urban agriculture consultant, Yilma Getachew, argues that “…organic agriculture is a valid strategy for both stimulating economic growth and developing markets…” and that he could verify this by his experience in supporting urban agriculture in three towns in Ethiopia. “Families in one town keep dairy cows either to supplement their meager salaries, or are totally dependent on milk and dung sales as their sole source of family income. In the other two towns, the main income source is the production of Irish potatoes and sweet potatoes together with a small amount of assorted vegetables not only selling to local markets but also to markets within a 200 kilometer radius. In this way, organic agriculture in an urban setting can both be a tool for community building (health and vitality) and development (income generation and marketing of scarce nutritious food).”(2) (1) http://en.wikipedia.org/wiki/Biointensive
(2) http://www.ruaf.org/sites/default/files/The%20Living%20Garden.pdf