@article{fdi:010027434,
  title = {{O}rganic matter management for soil conservation and productivity restoration in {A}frica : a contribution from francophone research},
  author = {{R}oose, {E}ric and {B}arth{\`e}s, {B}ernard},
  editor = {},
  language = {{ENG}},
  abstract = {{S}oil fertility is closely linked to soil organic matter ({SOM}), whose status depends on input, i.e., mainly biomass management, and output, i.e., mineralization, erosion and leaching. {P}reliminary results from runoff plots and lysimeters on hillslopes in {W}est {A}frica indicated that carbon losses by erosion and leaching ranged between 10 and 100 kg {C} ha?1 yr?1, depending on annual rainfall and vegetal cover. {U}nder natural conditions, losses may be low enough to be compensated by aerial deposits. {B}ut together with mineralization, erosion can locally be an important cause of {SOM} decrease in cropping systems where there is poor soil cover, steep slopes and erosive rain conditions. {T}he effect of previous erosion on cereal production was assessed in case studies from {R}wanda, {B}urundi, {C}ameroon, and {B}urkina {F}aso. {O}n the densely populated hillslopes of {R}wanda, hedges and manure reduced runoff and erosion efficiently, but did not succeed in improving grain yields due to {P}-deficiency of these ferrallitic soils. {I}n {B}urundi, under similar conditions but under banana plantation, tree density and mulch cover had a strong influence on erosion; this previous erosion had an important effect on the next maize yield, even when the soils were amended with manure, mineral fertilizers and lime. {O}n sandy ferruginous soils of {N}orth {C}ameroon, erosion increased with increasing tillage intensity. {M}anure application increased grain yield, but burying organic residues did not improve {SOM} levels and soil resistance to erosion. {M}ulching and tillage limited to the plant rows protected the topsoil against erosion, but did not clearly increase the yield. {M}anuring permitted the restoration of soil productivity, but additional mineral fertilizers ({P}, {N}) were needed to reach rapidly a high level of grain production. {I}n the same way, experiments conducted with traditional {Z}a{\¨ie} system for restoring a degraded {E}ntisol in {B}urkina {F}aso showed that runoff harvesting and organic matter input were not sufficient with no additional {N} and {P} fertilizers. {C}omplementary experiments in {C}ameroon showed that a 4-mm selective sheet erosion and a 50-mm non-selective de-surfacing resulted in similar yield decline. {L}ong fallowing, burning and grazing are traditional ways to utilize available biomass in {A}frica. {C}onsidering social habits and technical realities, it seems useful to balance ?grazing-manuring' and mulching in order to protect the soil and maintain its productive capacity. {M}inimum tillage with mulch (crop residues, weeds or legume fallow) is the new trend used for increasing crop production, with the help of herbicides. {A}groforestry that produces good-quality litter is also a part of the solution.},
  keywords = {{CONSERVATION} {DU} {SOL} ; {MATIERE} {ORGANIQUE} ; {EROSION} {HYDRIQUE} ; {ECOULEMENT} ; {METHODE} {DE} {LUTTE} ; {PRATIQUE} {CULTURALE} ; {TRAVAIL} {DU} {SOL} ; {ENGRAIS} ; {COMPOST} ; {BRULIS} ; {PATURAGE} ; {AGROFORESTERIE} ; {ETUDE} {DE} {CAS} ; {ZONE} {TROPICALE} ; {AFRIQUE} ; {RWANDA} ; {BURUNDI} ; {CAMEROUN} ; {BURKINA} {FASO}},
  booktitle = {},
  journal = {{N}utrient {C}ycling in {A}groecosystems},
  volume = {61},
  numero = {},
  pages = {159--170},
  ISSN = {1385-1314},
  year = {2001},
  DOI = {10.1023/{A}:1013349731671},
  URL = {https://www.documentation.ird.fr/hor/fdi:010027434},
}