Exploration of Responses to Potassium in Western Uruguay
Several regions of Uruguay has recently shown K deficiencies and responses. This project looks to determine the different areas with K deficiency, evaluate responses in the main field crops, and provide information on K soil testing.
IPNI-2007-URY-2
30 Dec 2009
2009 Annual Interpretive Summary
This research is partly based on previous observations of K deficiency and responses in field crops grown within the northwestern Uruguay region. Field experiments in the first 2 years of this study (2006/07 and 2007/08) have also showed significant responses to K fertilization.
For the 2008/09 season, three field experiments under corn, wheat/soybeans, and barley/soybeans were established at a site with exchangeable soil K of 0.33 cmol/kg (129 ppm), which is a low to medium soil test level for the region. Despite reduced yields caused by drought, all four crops showed significant response to K application: +250 kg/ha in wheat and barley (+14 to 16%), +500 kg/ha in doublecropped soybean (+20%), and almost 1,000 kg/ha in corn (+18%). Potassium fertilizer increased the number of spikes per m2 in wheat and barley, as well as flag leaf K concentration in barley. At harvest, exchangeable soil K levels were increased by 0.28 to 0.32 ppm per kg of applied K.
Additional field study and a compilation of research results for this and other projects is planned for the 2009/10 season. Uruguay-02