Synergy between farmers' knowledge of soil quality change and scientifically measured soil quality indicators in Wanka watershed, northwestern highlands of Ethiopia

This study was aimed at assessing farmers’ perception and knowledge of soil quality (SQ) change, in light of scientifically measured SQ indicators in the Wanka watershed, northwestern highlands of Ethiopia. Household survey, participatory SQ status assessment, key informant interview and laboratory analysis of selected SQ indicators were used as data collection tools. Independent samples t test (two-tailed) was used to compare the mean difference of SQ indicators between perceived good and poor SQ status. Farmers recognized that there has been SQ decline in their farm lands over the years. Based on perceived SQ status, farmers categorized their farm plots into good, average and poor classes locally called wofram meret, boda and sis/chincha meret, respectively. The identified principal SQ status indicators used by farmers were yield, plow depth, appearance of undesired weedy plant species, fertilizer requirement of soil, topsoil color and soil workability. These farmers’ assessment of SQ has well-coincided with major scientific quantitative indicators. Accordingly, plots identified by farmers as good SQ status exhibited better soil nutrients than the perceived poor SQ. Available phosphorus (p < 0.01) and exchangeable potassium (K +) (p < 0.01) were significantly higher in the reported good SQ plots. Conversely, sand content (p < 0.01) and bulk density (p < 0.05) were significantly high in poor SQ category. The synergy between perceived SQ status and scientifically measured SQ indicators signifies the relevance of farmers’ soil knowledge in characterizing SQ status of farm plots and manage them accordingly. Thus, strategies that incorporate farmers’ soil knowledge in land evaluation and sustainable land management practices should be developed and promoted