Sustainable Potato Production - Guidelines for - FAO.org

Soil conservationSoil erosion on tillage-based cultivatedlands is a problem that continues tothreaten the sustainability of bothsubsistence and commercialagriculture in potato growing areas aroundthe world. Potato cultivation usuallyinvolves intensive soil tillage throughout thecropping period, which often leads to soildegradation, erosion and leaching ofnitrates. During soil preparation, the entiretopsoil is loosened and – particularly onsticky clay soils – pulverized into smallaggregates to avoid the formation of clods inthe potato beds. Mechanical weeding andmechanized harvesting also entail intensivesoil disturbance.Good practicesThe use of mulch at planting and the “notill”land preparation method arerecommended to reduce soil degradation,erosion and nitrate pollution and to restoredegraded soils and achieve good potatoyields with reduced need for fertilizer. Themulch protects the soil from erosion duringthe first weeks of the crop.A green manure crop can be seededtowards the end of the crop, as the potatoplants are drying off. The cover crop willhelp to dry out the potato beds, contributingto healthier tubers with reduced risk ofdamage during harvest. Nevertheless, whilemulch planting of potatoes reduces the riskof erosion and nitrate leaching, it may havesome disadvantages (e.g. excessive moistureand reduced soil temperature leading toretarded plant emergence). Hence it shouldnot be a blanket recommendation.The “no-till” potato is pressed into thesoil surface, and then covered with a thicklayer of mulch, preferably straw, which isfairly stable and does not rot quickly. Theyoung potato tubers form under the mulchbut above the soil surface. In some cases –for example in dry areas under dripirrigation – black plastic sheets can also beused as mulch. Holes are punched in theplastic to allow the potato plant to growthrough it. During harvesting, the sheets areremoved and the potatoes are simply“collected”. Currently, the “no-till” potato isonly grown in small fields using manuallabour.51Potential areas of improvement3Promote conservation agricultureapproaches as a resource-saving cropproduction system.KEY INDICATORSOFSUSTAINABILITY