@article{fdi:010046037,
  title = {{T}emporal variability in soil hydraulic properties under drip irrigation},
  author = {{M}ubarak, {I}. and {M}ailhol, {J}. {C}. and {A}ngulo-{J}aramillo, {R}. and {R}uelle, {P}. and {B}oivin, {P}ascal and {K}haledian, {M}.},
  editor = {},
  language = {{ENG}},
  abstract = {{P}redicting soil hydraulic properties and understanding their temporal variability during the irrigated cropping season are required to mitigate agro-environmental risks. {T}his paper reports field measurements of soil hydraulic properties under two drip irrigation treatments, full ({FT}) and limited ({LT}). {T}he objective was to identify the temporal variability of the hydraulic properties of field soil under high-frequency water application during a maize cropping season. {S}oil hydraulics were characterized using the {B}eerkan infiltration method. {S}even sets of infiltration measurements were taken for each irrigation treatment during the cropping season between {J}une and {S}eptember 2007. {T}he first set was measured two weeks before the first irrigation event. {T}he results demonstrated that both soil porosity and hydraulic properties changed over time. {T}hese temporal changes occurred in two distinct stages. {T}he first stage lasted from the first irrigation event until the root system was well established. {D}uring this stage, soil porosity was significantly affected by the first irrigation event, resulting in a decrease in both the saturated hydraulic conductivity {K}-s and the mean pore effective radius xi(m) and in an increase in capillary length alpha(h). {T}hese hydraulic parameters reached their extreme values at the end of this stage. {T}his behavior was explained by the "hydraulic" compaction of the surface soil following irrigation. {D}uring the second stage, there was a gradual increase in both {K}-s and xi(m) and a gradual decrease in alpha(h) when the effect of irrigation was overtaken by other phenomena. {T}he latter was put down to the effects of wetting and drying cycles. soil biological activity and the effects of the root system, which could be asymmetric as a result of irrigation with only one drip line installed for every two plant rows. {T}he processes that affected soil hydraulic properties in the two irrigation treatments were similar. {N}o significant change in xi(m) and alpha(h) was observed between {FT} and {LT}. {H}owever, as a result of daily wetting and drying cycles, which were strongest in {LT}, the soil in this treatment was found to be more conductive than that of {FT}. {T}his showed that most of the changes in pore-size distribution occurred in the larger fraction of pores. {T}he impact of these temporal changes on the dimensions of the wetting bulb was studied using a simplified modeling approach. {O}ur results showed that there were marked differences in the computed width and depth of wetting bulb when model input parameters measured before and after irrigation were used. {A} temporal increase in capillary length led to a more horizontally elongated wetting bulb. {T}his could improve both watering and fertilization of the root zone and reduce losses due to deep percolation. {A}s a practical result of this study, in order to mitigate agro-environmental risks we recommend applying fertilizers after the restructuration of tilled soil. {F}urther studies using improved models accounting for temporal changes in soil hydraulic properties are needed.},
  keywords = {{S}oil hydraulic properties ; {B}eerkan infiltration method ; {S}tructural pores ; {D}rip irrigation ; {W}etting bulb},
  booktitle = {},
  journal = {{G}eoderma},
  volume = {150},
  numero = {1-2},
  pages = {158--165},
  ISSN = {0016-7061},
  year = {2009},
  DOI = {10.1016/j.geoderma.2009.01.022},
  URL = {https://www.documentation.ird.fr/hor/fdi:010046037},
}