engleski

Irrigation of Apple and Water-Melon Using the Coefficient of Irrigation

The goal of the investigations was to determine the onset of irrigation using the coefficient of irrigation, which is based on the calculation of everyday evapotranspiration. The coefficient of irrigation represents the water consumption (mm) per one degree of mean daily air temperature (oC ). Three-year investigations (1999-2001) were carried out at an apple plantation on the soil type Calcaric Fluvisol and water-melon plantation on the soil type Eutric Gleysol, hydromeliorated. Irrigation of apple was applied by means of mini sprinklers. Irrigation rate was calculated by the standard method and amounted to 47.6 mm. Irrigation of water-melon was applied by means of drip system and irrigation rate amounted to 15.6 mm, 31, 2 mm and 39, 0 mm. The coefficient of irrigation was estimated for decades periods according to the data on: soil moisture, precipitation, mean daily air temperature and the amount of water added with irrigation. The said data were processed to calculate the coefficient of irrigation, per decades, for the entire irrigation period. In 1999, the coefficient of irrigation for apple ranged from 0.17 mm/oC in the third decade of May to 0.40 mm/oC in the first and second decades of August. In 2000, the coefficient of irrigation ranged from 0.20 mm/oC in the first decade of May to 0.63 mm/oC in the third decade of August. In the last investigation year, the coefficient of irrigation amounted to 0.18 mm/oC in the first decade of May to 0.61 mm/oC in the second and third decades of August. In 1999, the coefficient of irrigation for water-melon ranged from 0.19 mm/oC in the second and third decades of May to 0.43 mm/oC in the third decade of June. In 2000 the coefficient of irrigation, ranged from 0.21 mm/oC in the second and third decades of May to 0.43 mm/oC in the third decade of June. In 2001, the coefficient of irrigation amounted to 0.25 mm/oC in the second decade of May to 0.47 mm/oC in the third decade of June. Water consumption for a particular day is calculated by multiplying the coefficient of irrigation by the mean daily air temperature (oC). When, in adding up the consumption of water per days, the previously added irrigation rate is spent, irrigation should be applied again. This fairly practical procedure of determining the onset of irrigation can be applied in a wider area with equal or similar pedological and climatic conditions.

coefficient of irrigation; apple; water-melon

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