Using a field water balance methodology to assess water production
functions for irrigated sugarcane (Saccharum Officinarum L.) in
semi-arid environment
Abstract
The water production function (Ky) defines the quantitative response of
the water deficit to overall yield during a given phenological stage and
is a key parameter in deficit irrigation planning in water-scarce
scenarios A three-year field trials were carried out on clay loam soil
of semiarid India in complete randomized blocks with 27 treatments and 2
replicates. Treatments consisted of applying irrigation depths
equivalents to 100%, 70% and 40% replenishments of the soil water
from the root zone at development, mid-season and end stages of
sugarcane. Each treatment was defined to investigate effect of specified
water depth on specified phenological stage independently. The actual
evapotranspiration (ETa) was determined by the field water balance of
the root zone while the Ky were calculated according to the FAO-33
report methodology. In particular, during the mid-season and development
stages, the referred yield decreases have been shown to be responsive to
water deficits. Seasonal Ky values ranged from 1.05 to 1.18 over 3
seasons with an average value of 1.11 showing sugarcane intolerant to
water deficit (Ky > 1). Based on the phenological stage
ETa, Ky values for development, mid-season and end stages were 0.31,
0.76 and 0.07, respectively. Ky values calculated for development and
mid-season stage in this research was different than FAO-33. It could be
concluded that during mid-season, water deficit must be avoided; 30 %
and 60 % water deficit are appropriate if applied respectively in the
in development and end stages.