Pulse Root Ideotype for Water Stress in Temperate Cropping System.

Area of Science:

• Agricultural Science
• Plant Physiology
• Agronomy

Background:

• Pulses are crucial for Southern Australian cropping systems, offering rotational benefits and profit potential.
• Cultivation is constrained by low soil water availability, irregular rainfall, and subsoil limitations in temperate climates.
• Optimizing pulse productivity requires enhanced soil water use and adaptation to soil constraints.

Purpose of the Study:

• To investigate root system architecture (RSA) as an adaptive strategy for pulse crops in water-limited temperate environments.
• To challenge the "Steep, Deep and Cheap" root ideotype, which is suboptimal for temperate systems.
• To propose a novel pulse-specific root ideotype for improved water capture and yield.

Main Methods:

• Review of existing literature on root system architecture in crop plants, with a focus on pulses.
• Analysis of pulse root traits and their adaptive potential for water stress tolerance and avoidance.
• Identification of genetic variability in pulse crops relevant to root system architecture.

Main Results:

• The "Steep, Deep and Cheap" ideotype is inefficient in temperate systems with limited deep water availability.
• Existing root studies predominantly focus on cereals, overlooking pulse-specific needs.
• A "Wide, Shallow and Fine" root system is proposed as a more suitable ideotype for temperate pulse cultivation.

Conclusions:

• A "Wide, Shallow and Fine" root system, with concentrated upper-layer root density, is proposed to enhance in-season rainfall capture.
• This ideotype holds potential for key pulse crops like chickpea, lentil, faba bean, field pea, and lupin.
• Further research into pulse RSA variability is crucial for developing strategies to overcome production constraints.