|Author:||Iniesta, F. ; Fereres, E. ; Goldhamer, D.A. ; Testi, L.|
|Book Group Author:||NA|
The reduction in agricultural water use in areas of scarce supplies can release significant amounts of water for other uses. As improvements in irrigation systems and management have been widely adopted by fruit tree growers already, there is a need to explore the potential for reducing irrigation requirements via deficit irrigation (DI). It is also important to quantify to what extent the reduction in applied water through DI is translated into net water savings via tree evapotranspiration (ET) reduction. An experiment was conducted in a commercial pistachio orchard in Madera, CA, where a regulated deficit irrigation (RDI) program was applied to a 32.3-ha block, while another block of the same size was fully irrigated (FI). Four trees were instrumented with six neutron probe access tubes each, in the two treatments and the soil water balance method was used to determine tree ET. Seasonal irrigation water in FI, applied through a full-coverage microsprinkler system, amounted to 842mm, while only 669mm were applied in RDI. Seasonal ET in FI was 1024mm, of which 308mm were computed as evaporation from soil (E s). In RDI, seasonal ET was reduced to 784mm with 288mm as Es. The reduction in applied water during the deficit period amounted to 147mm. The ET of RDI during the deficit period was also reduced relative to that of FI by 133mm, which represented 33% of the ET of FI during the deficit irrigation period. There was an additional ET reduction in RDI of about 100mm that occurred in the post-deficit period.
|Pages:||877 - 886|
|Journal:||Agricultural water management|
evapotranspiration, Pistacia vera, microirrigation, soilwater, pistachios, water use, quantitative analysis, irrigationmanagement, deficit irrigation, California