Reduced irrigation demand in maize cultivation through soil amendment with sheep wool: a natural water retention strategy

Abstract Background and aims Sheep wool (SW) is mostly underutilized and is treated as waste. This study investigates its ability to retain water in the soil. Methods After determining the chemical composition of SW, it was mixed with soil at ratios of 97.5:2.5 and 95:5-(soil:SW) in the first experiment, and 99:1, 98:2, and 97:3 in the second experiment. Silage maize plants were then grown in these soil-SW mixtures. Results Thermal camera imaging showed that SW treatments reduced canopy temperatures, indicating lower water and heat stress. Chlorophyll content increased with SW addition, peaking in the SW1 treatment (97.5:2.5 w/w) in the first experiment and in the SW2 treatment (98:2 w/w) in the second experiment. Stomatal resistance was generally higher in the first experiment but decreased with increasing SW levels in the second. Stomatal density increased across all SW treatments in both experiments. Pot weight confirmed that SW-treated pots retained more water. In the first experiment, maize dry weight increased with the SW1 treatment, while the highest dry weight was observed in SW2 treatment during the second experiment. Nutrient analysis showed significant increases in N and P concentrations with SW treatments. Potassium levels increased in the first experiment, while Ca and Mg showed variable responses across experiments. Manganese, Zn and Cu concentrations also increased with SW treatments. Conclusions This study highlights the potential of SW as a soil conditioner for improving water retention, nutrient uptake, and plant growth. Further research is recommended to optimize SW application rates across crop species and environmental conditions.