Modeling the effects of a partial residue mulch on runoff using a physically based approach

Abstract A partial covering mulch of residue on the soil strongly affects runoff dynamics, which consequently substantially reduces runoff amount. Experiments were conducted in la Tinaja (Mexico) on runoff plots (RPs) (20 m 2 ) of four different treatments (bare, unplanted with 1.5 t ha −1 of residue, planted with 1.5 and 4.5 t ha −1 of residue), to characterize mulch effects. During one crop cycle, rainfall and runoff flow were recorded at a 20 s time step. Soil moisture, crop leaf area index, saturated hydraulic conductivity and sorptivity were also measured. Mulch increased the infiltration rate of the topsoil layer, concentrated overland flow and slowed it down by increasing roughness and pathway tortuosity. The physically based model developed accounts for these mulch effects on runoff. The model consists of a production and a transfer module. Each RP is considered as a micro-catchment drained by a single channel. The production module accounts for rain interception by the plant and the mulch, soil retention and infiltration. The excess rainfall that cannot infiltrate defines runoff and is concentrated in the channel. The transfer module governs runoff flow out of the RP according to Darcy–Weisbach's law. The model was calibrated on 12 events (five parameters). Fitted parameters provided high Nash efficiencies ranging from 0.721 to 0.828. Both runoff hydrographs and volumes were well simulated. A sensitivity analysis was carried out on eight parameters and a partial validation was done on 14 independent events. The model can be used as a predictive tool to assess the effect of various types of mulch on runoff. All its parameters are physical and can be measured or derived from literature. The model can also simulate inner variables of interest (water depth in the channel, infiltration in the channel and the hillslopes, etc.) at any time during rainfall.

[1]  D. Swartzendruber.  INFILTRATION OF CONSTANT‐FLUX RAINFALL INTO SOIL AS ANALYZED BY THE APPROACH OF GREEN AND AMPT , 1974 .

[2]  Leonard J. Lane,et al.  Hydraulic Roughness Coefficients for Native Rangelands , 1992 .

[3]  J. T. Douglas,et al.  Predicting depressional storage from soil surface roughness. , 2000 .

[4]  A. Rutter,et al.  A predictive model of rainfall interception in forests, 1. Derivation of the model from observations in a plantation of Corsican pine , 1971 .

[5]  T. Steenhuis,et al.  Rainfall infiltration and runoff from an Alfisol in semi-arid tropical India. I. No-till systems , 1998 .

[6]  Garrison Sposito,et al.  Scale Dependence and Scale Invariance in Hydrology , 1998 .

[7]  John E. Gilley,et al.  Roughness Coefficients for Selected Residue Materials , 1991 .

[8]  Tammo S. Steenhuis,et al.  Scale Dependence and Scale Invariance in Hydrology: Scaling of the Richards Equation and Its Application to Watershed Modeling , 1998 .

[9]  P. Cellier,et al.  Modification of the soil temperature and water content regimes by a crop residue mulch: experiment and modelling , 1994 .

[10]  S. Recous,et al.  STICS : a generic model for the simulation of crops and their water and nitrogen balances. I. Theory, and parameterization applied to wheat and corn , 1998 .

[11]  James M. Gregory.  Time of Concentration Determination for Small Watersheds , 1982 .

[12]  Bofu Yu,et al.  The relationship between runoff rate and lag time and the effects of surface treatments at the plot scale , 2000 .

[13]  C. Valentin,et al.  Morphology, genesis and classification of surface crusts in loamy and sandy soils , 1992 .

[14]  M. R. Savabi,et al.  Plant Residue Impact on Rainfall Interception , 1994 .

[15]  J. Philip.  THE THEORY OF INFILTRATION: 1. THE INFILTRATION EQUATION AND ITS SOLUTION , 1957 .

[16]  Keith L. Bristow,et al.  Simulation of heat and moisture transfer through a surface residue—soil system , 1986 .

[17]  John E. Gilley,et al.  Maximum Surface Storage Provided by Crop Residue , 1994 .

[18]  B. Muller,et al.  Quantifying and modeling the effects of a light crop residue mulch on the water balance: an application to rainfed maize in Western Mexico , 1998 .

[19]  L. García-Torres,et al.  Conservation tillage impact on rainfed maize production in semi-arid zones of western Mexico. Importance of runoff reduction , 2001 .

[20]  J. Poesen,et al.  Effects of size and incorporation of synthetic mulch on runoff and sediment yield from interrils in a laboratory study with simulated rainfall , 1991 .

[21]  John E. Gilley,et al.  Beginning of Motion for Selected Unanchored Residue Materials , 1992 .

[22]  R. Haverkamp,et al.  Prediction of Crust-Induced Surface Runoff with Disc Infiltrometer Data , 1998 .

[23]  J. Delleur.  The handbook of groundwater engineering , 1998 .

[24]  Antoine Findeling,et al.  Etude et modélisation de certains effets du semis direct avec paillis de résidus sur les bilans hydrique, thermique et azoté d'une culture de maïs pluvial au Mexique , 2001 .

[25]  D. R. Linden,et al.  Earthworm Effects on Corn Residue Breakdown and Infiltration , 1989 .

[26]  Isabelle Braud,et al.  Modelling heat and water exchanges of fallow land covered with plant-residue mulch , 1999 .

[27]  John Wainwright,et al.  Resistance to overland flow on semiarid grassland and shrubland hillslopes, Walnut Gulch, southern Arizona , 1994 .