Suitability and benefits from intercropped sorghum-amaranth under partial root-zone irrigation

Area of Science:

• Agricultural Science
• Agronomy
• Sustainable Agriculture

Background:

• Food security in arid regions is challenged by the need for sufficient animal feed production.
• Intercropping drought-tolerant forages like sorghum and amaranth is hypothesized to improve feed yield and quality under water scarcity.

Purpose of the Study:

• To evaluate the impact of intercropping sorghum and amaranth on forage yield and quality under limited irrigation.
• To assess the effectiveness of water-saving irrigation techniques in enhancing feed production in arid environments.

Main Methods:

• Compared conventional furrow irrigation (CFI) with fixed alternate furrow irrigation (FFI) and alternate furrow irrigation (AFI).
• Evaluated various intercropping ratios of sorghum (S) and amaranth (A), including monocultures (S50-A50, sole sorghum, sole amaranth) and mixtures (S75-A25).
• Measured dry matter (DM) yield and irrigation water use efficiency (IWUE).

Main Results:

• FFI and AFI saved 22.5% and 19.7% irrigation water, respectively, but reduced forage yield and quality.
• Highest DM yield (15.5 Mg ha⁻¹) under CFI was from S50-A50; sole sorghum yielded highest under FFI and AFI.
• Sorghum monoculture and S75-A25 intercropping showed the highest IWUE (3.4 and 3.3 kg m⁻³), significantly outperforming sole amaranth (1.7 kg m⁻³).

Conclusions:

• Intercropping sorghum and amaranth improves emergency feed yield and quality when sufficient irrigation is available.
• The benefits of intercropping diminished under the partial root-zone irrigation methods (FFI and AFI) studied.
• Sorghum benefits from intercropping if its ratio exceeds 25%, indicating potential for optimized forage production strategies.