Cover crop evapotranspiration under semi-arid conditions using FAO dual crop coefficient method with water stress compensation

Cover cropping is a common agro-environmental tool for soil and groundwater protection. In water limited environments, knowledge about additional water extraction by cover crop plants compared to a bare soil is required for a sustainable management strategy. Estimates obtained by the FAO dual crop coefficient method, compared to water balance-based data of actual evapotranspiration, were used to assess the risk of soil water depletion by four cover crop species (phacelia, hairy vetch, rye, mustard) compared to a fallow control. A water stress compensation function was developed for this model to account for additional water uptake from deeper soil layers under dry conditions. The average deviation of modelled cumulative evapotranspiration from the measured values was 1.4% under wet conditions in 2004 and 6.7% under dry conditions in 2005. Water stress compensation was suggested for rye and mustard, improving substantially the model estimates. Dry conditions during full cover crop growth resulted in water losses exceeding fallow by a maximum of +15.8% for rye, while no substantially higher water losses to the atmosphere were found in case of evenly distributed rainfall during the plant vegetation period with evaporation and transpiration concentrated in the upper soil layer. Generally the potential of cover crop induced water storage depletion was limited due to the low evaporative demand when plants achieved maximum growth. These results in a transpiration efficiency being highest for phacelia (5.1 g m-2 mm-1) and vetch (5.4 g m-2 mm-1) and substantially lower for rye (2.9 g m-2 mm-1) and mustard (2.8 g m-2 mm-1). Taking into account total evapotranspiration losses, mustard performed substantially better. The integration of stress compensation into the FAO crop coefficient approach provided reliable estimates of water losses under dry conditions. Cover crop species reducing the high evaporation potential from a bare soil surface in late summer by a fast canopy coverage during early development stages were considered most suitable in a sustainable cover crop management for water limited environments

[1]  Keith L. Bristow,et al.  Current Capabilities and Future Needs of Root Water and Nutrient Uptake Modeling , 2002 .

[2]  J. Deckers,et al.  World Reference Base for Soil Resources , 1998 .

[3]  Ajay Kumar,et al.  Water use efficiency and crop coefficients of dry season oilseed crops , 2007 .

[4]  D. Nielsen,et al.  Legume Green Fallow Effect on Soil Water Content at Wheat Planting and Wheat Yield , 2005 .

[5]  C. Wagner-Riddle,et al.  Modeling a Rye Cover Crop and Subsequent Soybean Yield , 1997 .

[6]  Bingru Huang,et al.  Root Anatomical, Physiological, and Morphological Responses to Drought Stress for Tall Fescue Cultivars , 1998 .

[7]  A. D. Schneider,et al.  Evapotranspiration of Full-, Deficit-Irrigated, and Dryland Cotton on the Northern Texas High Plains , 2004 .

[8]  W. Wallender,et al.  Soil Physical Properties and Tomato Yield and Quality in Alternative Cropping Systems , 2000 .

[9]  T. Prichard,et al.  Soil surface strength and infiltration rate as affected by winter cover crops , 1992 .

[10]  M. L. Himmelbauer,et al.  Estimating length, average diameter and surface area of roots using two different Image analyses systems , 2004, Plant and Soil.

[11]  G. O'Leary,et al.  Interception of photosynthetically active radiation and radiation-use efficiency of wheat, field pea and mustard in a semi-arid environment , 2004 .

[12]  J. Odhiambo,et al.  Cover crop effects on spring soil water content and the implications for cover crop management in south coastal British Columbia , 2007 .

[13]  Rachapudi B. N. Prasad,et al.  A linear root water uptake model , 1988 .

[14]  O. Andrén,et al.  Root dynamics in barley, lucerne and meadow fescue investigated with a mini-rhizotron technique , 1987, Plant and Soil.

[15]  P. Kerkides,et al.  Semi-empirical approach for estimating actual evapotranspiration in Greece , 2001 .

[16]  H. Kage,et al.  Does transport of water to roots limit water uptake of field crops , 1996 .

[17]  Wesley W. Wallender,et al.  INFILTRATION AND SOIL WATER STORAGE UNDER WINTER COVER CROPPING IN CALIFORNIA’S SACRAMENTO VALLEY , 2002 .

[18]  M. Karrou,et al.  Physiological Responses of Spring Durum Wheat Cultivars to Early-season Drought in a Mediterranean Environment , 1998 .

[19]  T. Hata,et al.  Estimation of crop water requirements in arid region using Penman–Monteith equation with derived crop coefficients: a case study on Acala cotton in Sudan Gezira irrigated scheme , 2000 .

[20]  Mustafa Pala,et al.  Water-use efficiency and transpiration efficiency of wheat under rain-fed conditions and supplemental irrigation in a Mediterranean-type environment , 1998, Plant and Soil.

[21]  Gabriel G. Katul,et al.  The dynamic role of root-water uptake in coupling potential to actual transpiration , 2000 .

[22]  M. F. Allison,et al.  Integration of nitrate cover crops into sugarbeet (Beta vulgaris) rotations. I. Management and effectiveness of nitrate cover crops , 1998, The Journal of Agricultural Science.

[23]  Feike J. Leij,et al.  The RETC code for quantifying the hydraulic functions of unsaturated soils , 1992 .

[24]  F. Rego,et al.  Root distribution of a Mediterranean shrubland in Portugal , 2003, Plant and Soil.

[25]  Douglas E. Karcher,et al.  Batch Analysis of Digital Images to Evaluate Turfgrass Characteristics , 2005 .

[26]  K. Y. Li,et al.  An exponential root-water-uptake model with water stress compensation , 2001 .

[27]  P. Abbate,et al.  Climatic and Water Availability Effects on Water‐Use Efficiency in Wheat , 2004 .

[28]  N. Jarvis,et al.  A simple empirical model of root water uptake , 1989 .

[29]  M. Liedgens,et al.  Interactions of maize and Italian ryegrass in a living mulch system: (1) Shoot growth and rooting patterns , 2004, Plant and Soil.

[30]  J. C. van Dam,et al.  Field-scale water flow and solute transport: SWAP model concepts, parameter estimation and case studies. , 2000 .

[31]  Howard M. Taylor,et al.  Water Use in Agriculture. (Book Reviews: Limitations to Efficient Water Use in Crop Production) , 1984 .

[32]  W. H. Wischmeier,et al.  Predicting rainfall erosion losses : a guide to conservation planning , 1978 .

[33]  F. Salako,et al.  Soil water depletion under various leguminous cover crops in the derived savanna of West Africa , 2003 .

[34]  C. Dirksen,et al.  Simulation of root water uptake: II. Non-uniform transient water stress using different reduction functions , 2002 .

[35]  Wesley W. Wallender,et al.  A comprehensive experimental study with mathematical modeling to investigate the affects of cropping practices on water balance variables , 2006 .

[36]  M. R. Carter,et al.  Soil Sampling and Methods of Analysis , 1993 .

[37]  José Luis Araus,et al.  Water use efficiency in C3 cereals under Mediterranean conditions: a review of physiological aspects , 2007 .

[38]  R. Feddes,et al.  Parameterizing the soil-water-plant root system , 2005 .

[39]  L. Alakukku,et al.  Root growth dynamics and biomass input by Nordic annual field crops , 2005 .

[40]  R. Staples,et al.  Stress Physiology in Crop Plants , 1980 .

[41]  Abraham Blum.  Crop responses to drought and the interpretation of adaptation , 1996 .

[42]  E. J. Allen,et al.  Relationship between light interception, ground cover and leaf area index in potatoes , 1989, The Journal of Agricultural Science.

[43]  N. Paul,et al.  Effects of rust and post‐infection drought on photosynthesis, growth and water relations in groundsel , 1984 .

[44]  R. Belford,et al.  Growth, development and light interception of old and modern wheat cultivars in a Mediterranean-type environment , 1989 .

[45]  Elias Fereres,et al.  Evaporation Measurements beneath Corn, Cotton, and Sunflower Canopies , 1990 .

[46]  W. Frankenberger,et al.  Modification of Infiltration Rates in an Organic‐Amended Irrigated , 1992 .

[47]  C. Shennan,et al.  Changes in Soil Water Storage in Winter Fallowed and Cover Cropped Soils , 1999 .

[48]  Changming Liu,et al.  Estimation of Winter Wheat Evapotranspiration under Water Stress with Two Semiempirical Approaches , 2004, Agronomy Journal.

[49]  L. S. Pereira,et al.  Crop evapotranspiration : guidelines for computing crop water requirements , 1998 .

[50]  W. D. Reynolds.  Saturated hydraulic conductivity : field measurement , 1993 .