Revisiting the crop coefficient–reference evapotranspiration procedure for improving irrigation management
- 101 Downloads
The consumptive use of water by irrigated crops is typically quantified using the crop coefficient–reference evapotranspiration (Kc–ETo) procedure; yet, recent results showed that Kc might change with ETo, in response to high atmospheric demand. It is not known if the reduced Kc at high ETo applies to other crops with different aerodynamic features of the canopies. This paper seeks to provide the Kc values for soybean, wheat and potato, and propose an adaptation to the Kc–ETo procedure, hypothesising that the inverse relation between Kc and ETo would be general for all types of crops. Our results showed average Kc values of 0.90, 1.18 and 1.28, respectively, for soybean, wheat and potato cropping systems in the Brazilian cropping systems. However, Kc decreased as ETo increased, for all crops considered in this study, because of the increase of internal plant resistances to vapour diffusion from the leaves to the atmosphere. When ETo was above > 4 mm d−1, the water use by such crops was lower than that prescribed by Allen et al. (JAMA, 1998). The time-based Kc curves in Allen et al. (JAMA, 1998) are inappropriate for the studied crops under high demanding conditions and, besides the considerations suggested by Allen et al. (JAMA, 1998) (i.e., crop development stage, presence or absence of weeds), Kc recommendations for practical irrigation management should be based on the average ETo values of the previous days of the irrigation procedure.
The authors are grateful to Dr. Leandro G Costa for the work in part of the sugarcane experiment.
This study was funded by the Brazilian Research Council (CNPq, grant nos. 301424/2015-2 and 401662/2016-0) and the Research Foundation of the State of São Paulo (FAPESP, grant nos. 2000/12237-5, 2011/18072-2, 2014/12406-4, 2014/05887-6, 2017/20925-0, 2017/50445-0 and 2017/25894-5).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Allen RG, Jensen ME, Wright JL, Burman RD (1989) Operational estimates of reference evapotranspiration. Agron J 81(4):650–662. https://doi.org/10.2134/agronj1989.00021962008100040019x CrossRefGoogle Scholar
- Allen RG. Pereira LS, Raes D, Smith M (1998) Crop evapotranspiration: guidelines for computing crop water requirements. FAO Irrigation and Drainage Paper No. 56. FAO, Rome, ItalyGoogle Scholar
- Allen RG, Pruitt WO, Wright JL, Howell TA, Ventura F, Snyder R, Itenfisu D, Steduto P, Berengena J, Yrisarry JB, Smith M, Pereira LS, Raes D, Perrier A, Alves I, Walter I, Elliott R (2006) A recommendation on standardized surface resistance for hourly calculation of reference ETo by the FAO56 Penman–Monteith method. Agric Water Manage 81(1–2):1–22. https://doi.org/10.1016/j.agwat.2005.03.007 CrossRefGoogle Scholar
- Barros RS, Maestri M, Rena AB (1995) Coffee crop ecology. Trop Ecol 36:1–19Google Scholar
- Denmead OT, Shaw RH (1962) Availability of soil water to plants as affected by soil moisture content and meteorological conditions. Agron J 54:385–390. https://doi.org/10.2134/agronj1962.00021962005400050005x CrossRefGoogle Scholar
- Doorenbos J, Pruitt WO (1977) Crop water requirements. FAO Irrigation and Drainage Paper No. 24 (rev.). FAO, Rome, ItalyGoogle Scholar
- Franke AE, Konig O (1994) Determinação do coeficiente de cultura (K c) da batata (Solanum tuberosum L.), nas condições edafoclimáticas de Santa Maria, RS. Pesq Agropec Bras 29(4):625–630Google Scholar
- Gao Y, Yang L, Shen X, Li X, Sun J, Duan A, Wu L (2014) Winter wheat with subsurface drip irrigation (SDI): crop coefficients, water-use estimates, and effects of SDI on grain yield and water use efficiency. Agric Water Manag 146:1–10. https://doi.org/10.1016/j.agwat.2014.07.010 CrossRefGoogle Scholar
- Köppen W (1931) Grundriss der klimakunde [Outline of climate science]. Walter de Gruyter, BerlinGoogle Scholar
- McNaughton KG, Jarvis PG (1983) Predicting effects of vegetation changes on transpiration and evaporation. In: Koszlowski TT (ed) Water deficits and plant growth, vol 7. Academic Press, New York, pp 1–47Google Scholar
- Syvertsen JP, Lloyd JJ (1994) Citrus. In: Schaffer B, Andersen PC (eds) Handbook of environmental physiology of fruit crops: sub-tropical and tropical crops, vol 2. CRC Press, Boca Raton, pp 65–99Google Scholar
- Tardieu F, Zhang J, Gowing DJG (1993) Stomatal control by both [ABA] in the xylem sap and leaf water status: a test of a model for draughted or ABA-fed field-grown maize. Plant Cell Environ 16:413–420. https://doi.org/10.1111/j.1365-3040.1993.tb00887.x CrossRefGoogle Scholar
- Teare ID, Kanemasu ET (1972) Stomatal-diffusion resistance and water potential of soybean and sorghum leaves. New Phytol 71:805–810. https://doi.org/10.1111/j.1469-8137.1972.tb01959.x CrossRefGoogle Scholar
- Turner NC (1968) Stomatal resistance to transpiration in three contrasting canopies. Crop Sci 9(3):303–307. https://doi.org/10.2135/cropsci1969.0011183X000900030015x CrossRefGoogle Scholar