Effects of Season and Phenology-based Changes on Soil Erodibility and Other Dynamic RUSLE Factors for Semi-arid Winter Wheat Fields

• Published in: Journal of Agricultural Sciences (JAS) Vol. 27; no. 4; pp. 526 - 535
• Main Author: SAYGIN, Selen
• Format: Journal Article
• Language: English
• Published: Faculty of Agriculture, Ankara University 01.12.2021
• Subjects: erodibility; modeling; normalize different vegetation index (ndvi); satellite images; sustainability; water erosion
• ISSN: 1300-7580; 2148-9297
• DOI: 10.15832/ankutbd.749181

Time-dependent and phenology-based erodibility assessments in agricultural areas are extremely important for a more accurate evaluation of erosion. This paper aims to investigate soil erodibility factor (RUSLE-K) of the “Revised Universal Soil Loss Equation (RUSLE)” model in terms of phenological and seasonal variations in the 50 different winter wheat growing parcels with the interactions other dynamic RUSLE factors (RUSLE-R, RUSLE-C). For that, parcel-based erosion assessments were performed with the help of Dynamic Erosion Model and Monitoring System, digital elevation model, and satellite images in Polatlı, Ankara. Findings showed that RUSLE-K factor varied from 0.0150 to 0.0357 t ha h ha-1 MJ-1 mm-1 during the period the seeding germination to the end of the tillering from autumn to spring, and the lowest RUSLE-K was obtained when the plant was in the three-leaf stage. After the frost-free period, corresponding to the flowering and fertilization stages of the wheat plant, the RUSLE-K values changed between 0.0786 and 0.0976 t ha h ha-1 MJ-1 mm-1. This reveals that erodibility can vary up to nine times due to seasonality. However, the other dynamic model factors are not taken into consideration. Considering all dynamic factors on soil losses, the change coefficients from the highest to the lowest were obtained for RUSLE-R, RUSLE-K and RUSLE-C, respectively. These changes caused soil losses to change by 82% during the year. So, this study is expected to shed new light on studies of wheat or other commonly cultivated crops to accurately assess the water erosion risk as a significant land degradation problem.