Sustainability

Sustainable agriculture

As we have seen, the soil is essentially important for human survival. Men have developed agricultural techniques that allow to obtain good productions at limited costs. Sustainable agriculture derives from the integration of traditional agricultural techniques, that use chemical products like fertilizers and phytosanitary products, with low-environmental impact biological techniques that require a deep knowledge of complex interactions between the soil, water, vegetation and animals. Each year 30-80 billion tons of soil are lost due to erosion: it is as if a train full of earth was unloaded 12 times a year in the space. One of the most efficient techniques uses some plants, especially herbaceous plants that, keeping earth particles in their roots, reduce the erosive effect of wind and water. Often herbaceous varieties are seeded after covering the soil with a thick biodegradable net, of vegetal origin (raffia or hemp), which supports the seeds during their germination. Farmers adopt some measures to reduce or block the wind or water erosion. For example, they plant trees along the borders of the fields, they plant herbaceous crops (like cereals) in order to cover the soil during those months that are most at risk of erosion (autumn and spring), they work less on the soil, etc.