24
C. M. Flores-Cayuela et al.
Fig. 5 FIR irrigation strategy simulation (2019). a Precipitation distribution, effective rainfall.
b irrigation scheduling. c Evolution of the soil moisture depletion level throughout the crop season
with respect to ADL, RAW and TAW
The irrigation strategy in Fig. 5 makes a fortnightly distribution of available water
supply according to the historical needs of the crop. Since the water needs of the
orange crop are higher than the water allocation for the campaign, the daily irrigation
schedule is conditioned by the established water limit (IWA n ). This can be seen in the
nearly uniform staggering of irrigation during the season. In any case, even though
the strategy is focused on covering the crop’s needs, the total irrigation water applied
in the campaign is limited by the water allocation. The total irrigation water to be
applied following this strategy would be 495 mm, lower than the 500 mm allocation.
To satisfy its water needs, the plant uses water stored in the soil. Water reserves
in the soil decrease rapidly during the first months of the campaign due to the low
rainfall, bringing forward the start of the irrigation campaign to mid-March. Figure 5a
shows that the presence of several precipitation events in spring (approximately from
day 90 to day 120 DOY) raised the water content in the soil above the ADL level, so
irrigation was not necessary. Later, in the summer months, the water demand of the
crop was greater than the water input from irrigation, so the plant took some of the
water from the soil to cover part of its evapotranspiration demand.
The application of irrigation was limited by the water allocation (Fig. 5b), so it
was not possible to restore the optimal soil moisture level between FC and ADL,
increasing the soil moisture depletion level (Dr) until RAW was reached (Fig. 5c).
When this threshold was reached, water extraction was more difficult for the plant
and the ETC was reduced (K s < 1), so the rate of Dr depletion decreased. In the fall
C. M. Flores-Cayuela et al.
Fig. 5 FIR irrigation strategy simulation (2019). a Precipitation distribution, effective rainfall.
b irrigation scheduling. c Evolution of the soil moisture depletion level throughout the crop season
with respect to ADL, RAW and TAW
The irrigation strategy in Fig. 5 makes a fortnightly distribution of available water
supply according to the historical needs of the crop. Since the water needs of the
orange crop are higher than the water allocation for the campaign, the daily irrigation
schedule is conditioned by the established water limit (IWA n ). This can be seen in the
nearly uniform staggering of irrigation during the season. In any case, even though
the strategy is focused on covering the crop’s needs, the total irrigation water applied
in the campaign is limited by the water allocation. The total irrigation water to be
applied following this strategy would be 495 mm, lower than the 500 mm allocation.
To satisfy its water needs, the plant uses water stored in the soil. Water reserves
in the soil decrease rapidly during the first months of the campaign due to the low
rainfall, bringing forward the start of the irrigation campaign to mid-March. Figure 5a
shows that the presence of several precipitation events in spring (approximately from
day 90 to day 120 DOY) raised the water content in the soil above the ADL level, so
irrigation was not necessary. Later, in the summer months, the water demand of the
crop was greater than the water input from irrigation, so the plant took some of the
water from the soil to cover part of its evapotranspiration demand.
The application of irrigation was limited by the water allocation (Fig. 5b), so it
was not possible to restore the optimal soil moisture level between FC and ADL,
increasing the soil moisture depletion level (Dr) until RAW was reached (Fig. 5c).
When this threshold was reached, water extraction was more difficult for the plant
and the ETC was reduced (K s < 1), so the rate of Dr depletion decreased. In the fall