Humic acid effects on wind erosion control in sandy clay loam and clay loam soils: A wind tunnel study

Traditional tillage methods, based on intensive tillage and increasing drought due to global climate change, compromise the sustainable use of soils and increase the risk of wind erosion on agricultural land. Therefore, numerous methods including the application of various polymers to improve soil structure and increase aggregate stability have been used to overcome the soil problems caused by wind erosion. In this study, we aimed to evaluate the effects of humic acid on soil wind erosion control in a laboratory wind tunnel on 5 different locations with two different textures from Konya Province, Turkey. First, the air-dried soil was passed through a (1 mm) sieve, then poured into the pans and the samples were treated with humic acid corresponding to 0.5, 1, 2 and 4 L da-1. After 24 h, the samples were placed in a laboratory wind tunnel and exposed to a wind of 11 m s-1 for 10 min. The findings indicated that the application of humic acid significantly influenced briquette formation in soil samples 1, 2, and 3, which had a sandy clay loam (SCL) texture, successfully formed briquettes, while samples 4 and 5, characterized by clay loam (CL) texture did not produce any briquettes. Additionally, the study demonstrated that the application of humic acid to SCL soil effectively reduced soil loss, with the lowest recorded loss being 18.62 t ha-1 year-1 at a 1 L da-1 application of humic acid (HA). In contrast, CL textured soil samples experienced a maximum soil loss of 87.6 t ha-1 year-1 with a 4 L da-1 HA application. The results further suggest that the effectiveness of humic acid in controlling soil erosion was dose dependent for the CL textured soil samples. In conclusion, this study demonstrated that the application of humic acid could be a promising approach to improve soil quality, particularly in relation to soil texture, to mitigate soil loss caused by wind erosion.