Effect of irrigation regimes on carbon isotope discrimination, yield and irrigation water productivity of wheat

Authors : Sema KALE, Bülent SÖNMEZ, Sevinç MADENOĞLU, Kadri AVAĞ, Ufuk TÜRKER, Gökhan ÇAYCI, Ali Cihat KÜTÜK

Pages : 50-58

View : 15 | Download : 7

Publication Date : 2017-02-01

Article Type : Research Paper

Abstract :The present research study was carried out during the years 2009-2010 and 2010-2011 to identify the relationship between carbon isotope discrimination insert ignore into journalissuearticles values(δ); of grain and leaf, yield of winter wheat, and irrigation water productivity insert ignore into journalissuearticles values(IWP); under different water conditions in a semiarid climate. The field experiments were conducted with four different irrigation treatments insert ignore into journalissuearticles values(I1: rainfed: I2: irrigate when calculated soil water depletion is 60 mm below field capacity insert ignore into journalissuearticles values(full irrigation);; I3: two irrigations maximum, one at tillering and another at grain filling; I4: no irrigation after establishment until heading, after which irrigate when soil water depletion is 60 mm below field capacity);. The leaf insert ignore into journalissuearticles values(δL); and the grain insert ignore into journalissuearticles values(δG); carbon isotope discriminations, biomass, and grain yield insert ignore into journalissuearticles values(GY); were measured in the experiments and the harvest index insert ignore into journalissuearticles values(HI); and IWP were calculated. At the end of the study, taking a 2-year average, GY and HI were found to be 3.35 t ha-1, 4.53 t ha-1, 4.13 t ha-1, and 4.37 t ha-1 and 29%, 31%, 31%, and 32%, respectively, according to the treatments. The results showed a significant positive linear correlation between δ and GY. These results highlight that grain δ at the pre-anthesis stage could be beneficial for predicting yield under well-irrigated conditions. The highest IWP value was obtained from I4 treatment. δ-IWP and GY-IWP were negatively correlated. IWP can be indicated as an advantage in deciding about limited irrigation regimes for wheat production in arid areas. The results of the present study show that full irrigation treatment insert ignore into journalissuearticles values(I2); could be recommended in areas with no water shortage conditions. Moreover, limited irrigation such as treatment I4 at 4.8% level produced only optimum yield reduction and had the potential for saving approximately 50% of irrigation water.
Keywords : Carbon isotope discrimination, irrigation water productivity, winter wheat