Water footprint of maize in thailand

Abstract

Thailand is the third largest net virtual water exporter in relation to crop trade with the volume of 47 billion m3/yr.
Thus, one of the reasons of water scarcity in Thailand is possibly due to the export of the agricultural sector.
Maize is one of twelve economic field crops of Thailand, which is essential to the stock feed industry. In this study,
water footprint of maize in Thailand was calculated in details by using the monthly production statistics, daily
Meteorological date and crop coefficient experimented in Thailand. There are 3 steps in the computation as
follows: 1. Calculate the maize evapotranspiration 2. Evaluate the crop water use by the soil water balance
method in root zone 3. With the crop yield and fertilization data, water footprint is calculated. The results of this study show that the country-averaged water footprint of maize in Thailand equals to 1,132 m3/ton comprised of
894 m3/ton green and 237 m3/ton grey water footprints. Since maize cultivation is mostly in the rain-fed area
(99.2%), the blue water footprint in this study. Is negligible Udonthani province has the highest water footprint of
maize (1,368 m3/ton), while Phichit the lowest (953 m3/ton). Comparing with the results of Mekonnen and Hoekstra
(2010), this study shows the similar value of the country-averaged green water footprint of maize. However, the
grey water footprint was found to about double of previous study.