The effect of climatic parameters and organic-mineral fertilization on potato yields in a long-term field experiment

Abstract

The yield variability of potatoes over 12 years from 1980 – 2001 in a long-term fertilization experiment in Prague-Ruzyně was analysed. The regression analysis showed a positive linear relationship between yields and average temperature in April and May – the correlation coefficient (r) ranged from 0.47 – 0.78 in 24 treatments. A similar relation was found for the average minimum and maximum temperatures in the same months. The average temperature of 60-day period, 30 days before and after the date of planting, improved the fit – the r ranged from 0.67 – 0.85 in the treatments. The sum of winter precipitation (January to March) was also positively correlated with yields (r from 0.52 – 0.74) but the precipitation during growth was not. The simple indicator composed from average temperature and winter precipitation improved the fit to an average of 0.79 (r from 0.69 – 0.86), i.e., the indicator explained on average 62% of yield variability. The yield differences between fertilized treatments and unfertilized control increased with higher yields and thus also with temperatures around the time of planting and with higher precipitation in winter.

Keywords:

• Potatoes
• yield variability
• fertilization
• temperature
• precipitation

Acknowledgements

The study was supported by research project MZE 0002700601.