Agro-ecological functions of crop residues under conservation agriculture. A review
Ranaivoson L., Naudin K., Ripoche A., Affholder F., Rabeharisoa R.L., Corbeels M.. 2017. Agronomy for Sustainable Development, 37 (4) : 17 p..
Conservation agriculture, which is based on minimum tillage, permanent soil cover and crop rotations, has widely been promoted as a practice to maintain or improve soil quality and enhance crop productivity. To a large extent, the beneficial effects of conservation agriculture are expected to be provided by permanent soil cover with crop residues. Surface crop residues play an important role for crop growth through their benefits on soil-related structural components and processes in the agro-ecosystem, referred to in this study as agro-ecological functions. Through a meta-analysis of the literature, we have studied the relative effects of surface crop residue levels on the performance of a set of agro-ecological functions compared with a no-till bare soil, i.e., without surface residues. The selected agro-ecological functions were soil water evaporation control, soil water infiltration, soil water runoff control, soil loss control, soil nutrient availability, soil organic carbon (SOC) stocks and gains, weed control and soil meso- and macrofauna abundance. The potential effects of crop residue cover were quantified using boundary line models. Our main findings were (1) 8 t ha-1 of residues were needed to decrease soil water evaporation by about 30% compared to no-till bare soil. (2) To achieve the maximum effect on soil water infiltration, water runoff and soil loss control, residue amounts of at least 2 t ha-1 were required. (3) The effect of increasing the amounts of surface crop residues on soil nutrient supply (N, P and K) was relatively low; the boundary line models were not significant. (4) The average annual SOC gain increased with increasing amounts of residues, with a mean of 0.38 t C ha-1 year-1 with 4 to 5 t ha-1 of residues. (5) Weed emergence and biomass can be reduced by 50% compared to a no-till bare soil with residue amounts of 1 t ha-1 or more. (6) There was a weak response in soil meso- and macrofauna abundance to increasing amounts of surface crop
Mots-clés : agroécologie; résidu de récolte; agriculture alternative; eau du sol; évaporation; infiltration; érosion; matière organique du sol; mauvaise herbe; faune du sol; non-travail du sol; mulch; performance de culture; pratique culturale; ruissellement; culture sous couvert végétal; perte par le sol; teneur en éléments minéraux; potassium; phosphate; agriculture de conservation
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Agents Cirad, auteurs de cette publication :
- Affholder François — Persyst / UPR AIDA
- Corbeels Marc — Persyst / UPR AIDA
- Naudin Krishna — Persyst / UPR AIDA
- Ranaivoson Lalaina — Persyst / UPR AIDA
- Ripoche Aude — Persyst / UPR AIDA