The use of alternative irrigation and cropping systems in forage production may alleviate the water scarcity in semi-arid regions.

BACKGROUND: Strategies to enhance the efficient use of irrigation water require a major shift in irrigation and cropping systems. It was hypothesized that (i) replacing water-demanding crops such as corn silage with more drought-tolerant forages species, (ii) adoption of intercropping instead of monoculture, and (iii) use of alternative irrigation methods, may alleviate the water shortage in semi-arid regions, while producing high-quality forage. RESULTS: Adoption of drip irrigation (DRIP) and alternate furrow irrigation (AFI) reduced water consumption by 43% and 20%, respectively. Additionally, DRIP produced 11% more biomass than the conventional furrow irrigation. The intercropped ratio of 50% sorghum and 50% amaranth under DRIP maximized forage production and improved irrigation water-use efficiency (IWUE). Principal component analysis indicated that the DRIP increased the dry matter yield and IWUE, whereas the AFI improved the forage quality. The intercropped ratio of 75% sorghum and 25% amaranth demonstrated the highest yield stability and was considered superior cropping system regardless of the irrigation strategies. CONCLUSIONS: DRIP and AFI strategies were effective in reducing water consumption, with DRIP being the most water-efficient method. Intercropping sorghum and amaranth at a ratio of 50:50 under DRIP resulted in the highest forage yield and IWUE. While sole amaranth had the highest forage quality, intercropping sorghum and amaranth increased dry matter production with better forage quality than sorghum monoculture. Overall, the combination of DRIP and intercropping sorghum and amaranth at a ratio of 50:50 considered as a suitable strategy for improving forage yield and quality, as well as IWUE. © 2023 Society of Chemical Industry.

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

BACKGROUND: 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. RESULTS: 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 15.5 Mg ha-1 , obtained from S50 -A50 treatment. In FFI and AFI, sole sorghum produced the highest DM. However, their maximum yields (11.2 and 12.6 Mg 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 3.3 kg m-3 ), whereas IWUE of the sole amaranth was 1.7 kg 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%. CONCLUSION: 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.