.:: Lao Knowledge Base on Conservation Agriculture ::.

Overview on Conservation Agriculture

Conservation Agriculture is an agroecological approach associating rural development with environmental preservation. It is a generic concept integrating the whole agricultural practices and aiming both at viability and sustainability of agriculture and environment protection.

At the field level, CA is based on direct seeding mulch-based cropping systems (DMC). Three main principles characterize these systems:

Minimum soil disturbance to avoid soil erosion, loss of organic matter and minerals, and preventing water loss.
Permanent organic soil cover which protects the soil from rainfall stress, erosion and climatic variation (buffer effect). This mulch layer promotes the development of a high biological activity enhancing the physical, biological and chemical parameters of the soil (soil structure, nutrients availability, water and gas exchanges…).
Relevant crop sequences and rotations using multipurpose species, reducing both climatic and economic risks, allowing integrated pest and weeds management and enhancing biodiversity. The use of strong-rooting efficient plants promotes impressive ‘biological tillage’ of the soil in conjunction with the work of earthworms.

Direct sowing of maize with a two rows Knapik

Almost all advantages of DMC system come from the permanent cover of the soil. Full soil cover is the key factor for successful Conservation Agriculture systems and for Sustainable Agriculture: continuous organic matter flux influences soil aggregation, soil structure and as a consequences influences air flux, water retention, and nutrients cycling.

At the level of the village land, catchment and landscape scales, CA includes land and water management practices (Séguy and Bouzinac, 2008):

(re)constitution of gallery forests (multiple species incorporating medicinal plants, timber and non‑timber forest products) to help protect water courses and recreate a powerful natural filter limiting the risks of pollution by pesticides and suspended particles,
establishment of living hedges around fields using fast-growing species with multiple uses (paper mulberry, elephant grass, Acacia sp.) and maintaining woodland corridors essential for the movement of wildlife,
protection of weak zones upstream of these catchment areas by reforestation and use of species with a strong covering potential (Brachiaria sp., Stylosanthes guianensis, etc.),
elaboration and dissemination, on a landscape unit scale, of diversified direct seeding no-till agriculture systems incorporating livestock, optimizing forage production and use.

Gallery forests protecting water courses, creating a powerful natural filter and maintaining woodland corridors essential for the movement of wildlife