use of open pollinated seeds ensures genetic diversity, and allows the farmer to be self-sufficient, harvesting seeds from his or her own plants, and cultivating varieties which are best suited to that particular region. The Whole System: biointensive experts emphasize that because these techniques can result in intense productivity and high yields, the system must be practiced as a whole in order to prevent rapid soil exhaustion. The goal of the biointensive method is sustainability, but if the techniques concerning productivity are practiced without integrating the techniques concerning sustainable soil fertility, the soil may be depleted even more rapidly than with conventional farming methods. The most important element for building and maintaining sustainable soil fertility is the growing of 60% compost crops, proper composting techniques that incorporate the right balance of mature carbonaceous brown and green nitrogenous compost materials, and when possible, safe and legal human waste recycling. Animals The biointensive method typically concentrates on the vegan diet. This does not mean that biointensive farming must exclude the raising of animals. Animals, while not considered by biointensive practitioners to be sustainable, can be incorporated into biointensive systems, although they increase the amount of land and labor required considerably. The following is excerpted from an article on the topic of integrating animals into a biointensive system from the “Frequently Asked Questions” page on Ecology Action's website: Livestock can fit into a [biointensive] system, but it usually takes a larger area [than growing a vegan diet]. Normally it takes about 40,000 sq ft of grazing land for 1 cow/steer (for milk/meat) or 2 goats (for milk/meat/wool), or 2 sheep (for milk/meat/wool). [In contrast] With [biointensive farming] and maximizing the edible calorie output in your vegan diet design, one person’s complete balanced diet can be grown on about 4,000 sq ft—a much smaller area. The challenge [to growing animals for food] is that by 2014, 90% of the world’s people will only have access to about 4,500 sq ft of farmable land per person, if they leave an equal area in a wild state to protect plant and animal genetic diversity and the world’s ecosystems! As you will see from the information that follows on the land requirements for incorporating livestock, this becomes a challenge. The article goes on to estimate the square footage required to grow fodder for various animals (and compost to replenish the soil), and provides a discussion on whether