Reducing tillage promotes soil integrity, prevents erosion and limits the use of machinery and herbicides. Conservation agriculture appears to be both a sustainable and profitable practice.
Soil erosion, land degradation and the overuse of pesticides are among the "cardinal sins" of modern agriculture. Traditional cultivation techniques involve intensive use of machinery, aimed at turning the soil to encourage rapid germination and deep penetration of nutrients and inputs. In South America and Eastern Europe, however, a new approach has taken hold that is gradually gaining traction in Italy too: conservation agriculture. This encompasses a range of cultivation techniques sharing a common principle — the elimination of ploughing or, more broadly, the reduction of soil tillage to an absolute minimum, limiting the frequency, intensity and depth of interventions.
Conservation agriculture is a sustainable technique, widely adopted around the world — the area managed in this way is estimated at over 95 million hectares — and aims to minimise disturbance to the land in order to preserve its structure, fauna and organic matter. Permanent soil cover provided by specific crops, residues and mulches protects the surface, retains moisture and helps keep weeds in check without resorting to herbicides. The direct benefits of reduced land exploitation are accompanied by positive side effects, including lower use of machinery and the consequent reduction in both fuel consumption and pollutant emissions, support for biodiversity, minimal use of both pesticides and fertilisers, and protection of groundwater reserves.
Conservation agriculture aims to optimise resources and limit soil degradation, particularly erosion. Reduced tillage techniques are specifically divided into four broad categories. The most radical practice, known as "no tillage", involves the complete abandonment of both ploughing and any activity that causes even superficial soil disturbance, relying instead on direct drilling into undisturbed soil. "Minimum tillage", by contrast, is based on shallow interventions, usually no deeper than 15 cm, with at least 30 per cent of the land surface covered by crop residues, while "vertical tillage" relies on vertical cuts through the soil crust, made with implements that do not cause mixing of the topsoil. "Strip tillage", finally, involves working only strips of soil no more than twenty cm wide, affecting no more than 25 per cent of the cultivated surface with these passes.
Particularly widespread in emerging countries thanks to the reduced use of machinery, conservation agriculture is gradually gaining ground in our country too. While requiring a stabilisation period of at least 5–7 years, this practice typically leads to an increase in yields per hectare and encourages crop rotation. To be put into practice, however, it requires specific equipment ranging from (minimal but necessary) soil management to sowing, without overlooking precision fertilisation, so as to minimise overdosing and the dispersal of inputs into the environment. A new, sustainable approach to cultivation.