Use of the Sensor-Based Approach in Mexico - Potential to Adapt Nitrogen Recommendations.

The nitrogen use efficiency of irrigated wheat in the Yaqui Valley of Mexico is only 31%.  Studies in the Yaqui Valley have documented important emissions of nitrous oxide, leaching losses as well as runoff to the Sea of Cortes (Golf of California). The main cost of production for irrigated wheat in this area is fertilizer use with about 25 to 37% of total cost of production depending on the year.  There are two main factors associated with the low N use efficiency in the Yaqui Valley.  One is the correct rate and the second one is the correct timing.   To address the issue of the correct rate we have been using the GreenSeeker sensor as a diagnostic tool, which has been calibrated for this area.  In the last years adoption of this technology has fluctuated between 5000 and 8000 hectares.  Evaluations have shown that farmers that adopt this technology save on average ~ 70kgN/ha, while maintaining the same yield as farmers that apply the full N rate.  Average yields in the area are around 6 to 7 tons of wheat per hectare.  Farmers are able to reduce their N rate to 180 kgN/ha while farmers that do not use the sensor apply 250 kgN/ha.  Therefore, those savings in fertilizer represent additional income to the farmers and less impact on the environment.