Water use of pulse crops at various plant densities under fallow and stubble conditions in a semiarid environment

Abstract

Understanding water use characteristics of crops is essential for optimizing crop productivity in semiarid environments. This study determined water use (WU), water use efficiency (WUE), and postharvest residual soil water (PHRSW) of dry pea (Pisum sativum L.) and desi and kabuli chickpea (Cicer arietinum L.) at four plant densities under fallow and stubble cropping systems in a semiarid environment. Crops were grown in southwest Saskatchewan from 1998 to 2000. Chickpea used 28% more water than dry pea, while kabuli chickpea used 14% more water than desi chickpea only when grown on fallow at one of the sites. Pulses grown on fallow used 66% more water than when grown on stubble, with largest difference (48%) in WU between the two cropping systems being in the 60- to 90-cm soil depths. Overall, dry pea had the greatest WUE (12.9 kg ha-1 mm-1), followed by desi chickpea (7.3 kg ha-1 mm-1) and kabuli chickpea (6.6 kg ha-1 mm-1). Water use efficiency increased with increasing plant density for all the pulses, with dry pea showing a stronger response than chickpea. The PHRSW below the 60-cm depth differed significantly among pulses. Dry pea left an average of 33 mm available water at harvest, the desi left 20 mm, and the kabuli 13 mm. A deeper rooting crop grown after dry pea may benefit more from water conservation in the soil profile than when grown after chickpea under semiarid environmental conditions. Key words: Cicer arietinum, Pisum sativum, water use efficiency, rooting depth