@inproceedings{PAR00007401,
  title = {{S}lumping dynamics of tilled sandy soils in {N}orth-{E}ast {T}hailand},
  author = {{H}ao, {H}. and {H}artmann, {C}hristian and {R}ichard, {G}. and {B}ruand, {A}. and {A}pichart, {J}. and {S}iwaporn, {S}. and {D}exter, {A}.{R}.},
  editor = {},
  language = {{ENG}},
  abstract = {{R}ecompaction of tilled layers, under the effect of rainfall or irrigation only (i.e. without any external loading), was called slumping by {M}ullins et al. (1990). {I}t has been observed in various soil types with negative effects on plant production. {O}ur objective was to characterise the dynamics of slumping at the ploughed layer scale in a sandy soil of {N}orth {E}ast {T}hailand. {A}n experimental field was tilled to two depths (20 and 40 cm) with or without ridges and furrows and was submitted i) to natural rainfall during two months (214mm in {J}une and {J}uly 2007) or ii) to experimental flood irrigation (100 or 200 mm over some hours). {C}hanges in bulk density with time were observed, particularly under flooding and after heavy daily rainfall. {F}inal bulk density of 1.60 {M}g m 3 has been measured over 20 cm depth while initial bulk density after tillage was 1.25 {M}g m 3. {B}ulk density profiles were often characterised with two maximum values, either in the top layer (0-5 cm) or at the bottom of the ploughed layer (15-20 or 35-40 cm). {W}e demonstrated that several processes occurred simultaneously: i) a redistribution of sand particles from the top of ridges to the bottom of furrows that decreased soil roughness, ii) a 2 to 5 cm topsoil collapse when water infiltrated, iii) a soil collapse at greater depths due to overburden pressure. {T}hese phenomena agree with the theory of granular material and the decrease in capillary forces between sand grains during wetting. {T}he specific changes in bulk density profiles induced by rainfall should allow the occurrence of slumping to be predicted or identified as a function of soil, climate and tillage conditions.},
  keywords = {bulk density ; capillary forces ; internal force ; recompaction ; soil water potential ; {THAILANDE}},
  numero = {},
  pages = {7},
  booktitle = {},
  year = {2009},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00007401},
}