@article{fdi:010049361,
  title = {{P}ossibilities of carbon and nitrogen sequestration under conventional tillage and no-till cover crop farming ({M}ekong valley, {L}aos)},
  author = {{D}e {R}ouw, {A}nneke and {H}uon, {S}. and {S}oulileuth, {B}. and {J}ouquet, {P}ascal and {P}ierret, {A}lain and {R}ibolzi, {O}livier and {V}alentin, {C}hristian and {B}ourdon, {E}mmanuel and {C}hantharath, {B}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}here is limited information, particularly in the tropics, of farming systems that loose or accumulate carbon in their soils. {W}e compared no-till with a mulch-providing cover crop with conventional tillage without cover crop. {S}ide effects were also investigated, weeds, surface crusting, soil macrofauna, infiltration, porosity and roots. {T}he study site was a flat sandy clay loam. {T}reatments were maintained over five years; within this period, the time between the first and last soil sampling was exactly four years. {B}oth times the same profile locations and exactly the same depths were sampled thereby greatly reducing inherent soil variability. {S}oil was sampled at five increments from 0 to 40 cm depth. {T}he biomass contributions of maize, cover crop and weeds were measured. {T}he main findings were: (1) {T}he cover crop that was alleged to {S}upply extra inputs to the no-till system failed to do so because the weeds in the tillage treatment became as efficient in accumulating biomass as the planted cover crop. (2) {W}ith equal organic inputs over four years (43.0 {M}g dry weight ha(-1) incorporated into the soil under conventional tillage, and 44.2 {M}g dry weight ha(-1) remaining on the soil surface as mulch under no-till), the tillage system stored (0-40 cm) significantly soil carbon (+590 g {C} m(-2)), whereas the no-till lost carbon (-133 g {C} m(-2)). {T}he difference between the systems was significant. {C}arbon accumulated just below the plough layer. {N}itrogen stocks remained unchanged. {A} very significant lowering of the {C}:{N} ratio occurred under no-till. {T}he process of transforming the available biomass on the soil surface into organic matter is apparently too slow to avoid direct losses under no-till. {A}lternatively, ploughing plant residues into the soil enables to capture some of what would otherwise be lost as {CO}2 through decay, thereby increasing soil carbon. (3) {I}n the last three years of the experiment, maize grain yields and crop residues stabilized at a lower level but were significantly higher under no-till, 16% and 34%, respectively. {H}igher yields were attributed to more soil water tinder no-till due to improved soil structure, though bulk density was not affected. {T}he mulch layer protecting the soil surface favoured infiltration by keeping it crust-free. {W}ater availability was further promoted by a better connectivity of pores and more macrofauna. {H}owever, the no-till system depended heavily on fertilizers and herbicides. {T}he lack of effectiveness of herbicides against shifting weed communities threatens the continuation of the system.},
  keywords = {{M}aize ; {W}eeds ; {R}uzi grass ; {E}arthworms ; {S}urface crusts ; {R}oots ; {LAOS}},
  booktitle = {},
  journal = {{A}griculture {E}cosystems and {E}nvironment},
  volume = {136},
  numero = {1-2},
  pages = {148--161},
  ISSN = {0167-8809},
  year = {2010},
  DOI = {10.1016/j.agee.2009.12.013},
  URL = {https://www.documentation.ird.fr/hor/fdi:010049361},
}