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

Abstract

The production of sufficient animal feed in arid and semi-arid regions plays a significant role in food security in these areas. The present study was conducted based on the hypothesis that intercropping of sorghum and amaranth, comprising relatively drought tolerant forages, will enhance the yield and quality of the feed under limited irrigation water availability. Implementation of fixed alternate furrow irrigation (FFI) and alternate furrow irrigation (AFI) resulted in a saving of 22.5% and 19.7% of irrigation water, respectively. However, the water saving declined both yield and quality of forage. In conventional furrow irrigation (CFI), the highest dry matter (DM) yield was 15.5Mg ha-1 , obtained from S50 -A50 treatment. In FFI and AFI, sole sorghum produced the highest DM. However, their maximum yields (11.2 and 12.6Mg ha-1 , respectively) were not significantly different from yields in S75 -A25 intercropping ratios. Irrigation water use efficiency (IWUE) was similar in CFI and AFI and considerably higher than FFI. Sorghum monoculture and the S75 -A25 intercropping had the highest IWUE (3.4 and 3.3kg m-3 ), whereas IWUE of the sole amaranth was 1.7kg m-3 . The partial land equivalent ratio and monetary advantage index of amaranth and sorghum indicated that sorghum would benefit from intercropping as long as its ratio in the intercropping is more than 25%. When sufficient irrigation is available, intercropping of sorghum and amaranth can considerably improve yield and quality of emergency feed. However, the benefits from intercropping faded under the two partial root-zone irrigation methods used in the present study. © 2021 Society of Chemical Industry.