Evapotranspiration of winter wheat estimated with the FAO 56 approach and NDVI measurements in a temperate humid climate of NW Europe

Philipp Drerup, Holger Brueck and Heinrich W. Scherer

Agricultural Water Management, 2017, vol. 192, issue C, 180-188

Abstract: Irrigated agriculture is the dominant user of global freshwater resources and improvements in water management are considered key to simultaneously enhance food production and to secure regional water resources. Irrigation management requires reliable estimates of crop evapotranspiration (ETa) which can be derived from tabulated crop coefficients and estimates of phenological stage lengths or alternatively from remotely sensed canopy data. In order to compare both approaches under sufficient nitrogen and water supply, field trials with winter wheat (Triticum aestivum L.) were performed in 2013/14 and 2014/15 at Duelmen, Germany. Crop growth dynamics were measured by a handspectrometer and leaf canopy analyzer, and phenological stages were recorded. ETa was calculated in two different ways: Firstly based on tabulated crop coefficients (Kc) and stage durations (FA-approach) and secondly based on remotely sensed Kc-values (NDVI-approach). Both approaches were used to calculate a daily field water balance (FWB) and compared with measured (FDR-techniques) dynamics of soil water content. Both ETa estimates predicted seasonal dynamics of the FWB reasonably good RMSE: 0.7, 0.6 (FA-approach); 0.6, 0.8 (NDVI-approach) in 2014 and 2015, respectively. ETa estimates of the FA approach for 2014 and 2015 were 403mm and 430mm and exhibited larger between-year variation when the NDVI approach was used (377mm and 463mm). Agronomic water-use efficiencies varied between 1.93–2.76g/l. The relevance of reliable in-field estimates of Kc-values and stage lengths was quantified with a sensitivity analysis. The results indicate that NDVI-based estimates of ETa can be used instead of ETa estimates which are based on tabulated Kc values and estimates of growth stage length. The use of NDVI-based estimates of ETa enables to apply irrigation water more site-specific.

Keywords: Crop coefficient; Stage duration; Sensitivity analysis (search for similar items in EconPapers)
Date: 2017
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (7)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0378377417302391
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:agiwat:v:192:y:2017:i:c:p:180-188

DOI: 10.1016/j.agwat.2017.07.010

Access Statistics for this article

Agricultural Water Management is currently edited by B.E. Clothier, W. Dierickx, J. Oster and D. Wichelns

More articles in Agricultural Water Management from Elsevier
Bibliographic data for series maintained by Catherine Liu ().