Resumo

GONZALEZ ROBAINA, Felicita; HERRERA PUEBLA, Julián  e  LOPEZ SEIJAS, Teresa. Water productivity of corn, soybean and sorghum in Red Ferralitic soils of the south of Havana . Rev Cie Téc Agr [online]. 2010, vol.19, n.1, pp.95-97. ISSN 2071-0054.

The study of the crop water production function is an important strategy to increase the water productivity. Using a data base of 25 experiments carried out at the Irrigation and Draining Research Station located in Alquizar at south of Havana Province (red ferralitic soils), and with the help of regression tools, it was estimated the crop water productivity (WP) (based on irrigation water applied and total water) and crop yield response factor (Kr) for corn, soybean and sorghum. The corn, soybean and sorghum WP_I was 16,43; 2,96 y 4,23 kg/m³ when were applied 266,8; 600 y 800 m³/ha irrigation water, respectively. The range 0,86 to 2,9 kg/m³ of WP_T obtained for maize, was in a wider range than the range reported by FAO for this crop. The soybean WP_T varied between 0,28 and 0,81 kg/m³, while sorghum varied between 0,49 and 0,96 kg/m³. Every cubic meter of total water used in maize yield 1,93 kg, while in soybean and sorghum it was 0,49 y 0,68 kg/m³ respectively. The slope (Kr) of the maize water productivity function was 1,67 in winter and 2,31 in summer. Soybean and sorghum showed similar response to water deficit in winter. Maize was the only crop where the relative loss of yield was proportional to deficit irrigation. For a planned irrigation deficit of 20% for maize it will expect a relative loss of 33,4% and 46,2% of yield, in winter and summer respectively.

Palavras-chave : crop yield response factor; deficit irrigation; Zea may; Glycine max; Sorghum vulgare.