Water use and crop coefficient of subsurface drip-irrigated lettuce in Central Arizona

Revista Brasileira de Engenharia Agrícola e Ambiental

Slack, Donald C.²  Pegelow, Edward J.⁴  Martin, Edward C.²  Folta, Allen D.¹  Oliveira, Aureo S. de³ 

[1] University of Arizona, USA;Universidade Federal da Bahia, Cruz das Almas;University of Arizona

关键词: SDI;    Lactuca sativa;    lysimeter;    evapotranspirationRESUMO Um estudo conduzido na Fazenda Experimental Maricopa (33º04'07" N;    111º57'18" W);    pertencente à Universidade do Arizona;    USA;    nos anos agrícolas de 1996/97 e 1997/98;    objetivou determinar o uso de água e derivar coeficientes de cultura (Kc) da alface de cabeça irrigada por gotejamento subsuperficial e cultivada em lisímetros de pesagem intermitente;   

DOI  :  10.1590/S1415-43662005000100006

学科分类：农业科学（综合）

来源: Universidade Federal de Campina Grande * Centro de Ciencias e Tecnologia

【 摘 要 】

A two year field study (1996/97 and 1997/98 growing seasons) was carried out at the Maricopa Agricultural Center (33º04'07" N; 111º57'18" W) of the University of Arizona, USA, to investigate the water use and to derive Kc's for subsurface drip-irrigated head lettuce grown in small weighable lysimeters. Measurement periods ranged from 480 to 1100 ºC-day (96/97) and from 439 to 1098 ºC-day (97/98). These intervals corresponded essentially to the second half of the crop cycle which amounted to a 1100 ºC-day, on average. The lysimeters were weighed periodically and the computation of the water balance revealed an average water use of 117 mm. Basal crop Kc was expressed as a function of cumulative growing degree days following a multiple linear regression procedure in which the data were fitted with a Fourier sine series model with up to six coefficients. Two-year Kc curves were obtained based on the Hargreaves, FAO Penman and FAO Penman-Monteith equations and compared to the AZSCHED (AriZona SCHEDuling) irrigation package. Predicted Kc peaked 0.88, 0.80 and 0.81 with the Hargreaves, FAO Penman, FAO Penman-Monteith equations, respectively, in the range of 1000 to 1050 ºC-day, in contrast to AZSCHED which predicted the peak Kc to be 1.01 at 1150 ºC-day.

【 授权许可】

CC BY-NC