ASSESSING FARMERS' KNOWLEDGE OF WEED SPECIES, CROP TYPE AND SOIL MANAGEMENT PRACTICES IN RELATION TO SOIL QUALITY STATUS IN MAI-NEGUS CATCHMENT, NORTHERN ETHIOPIA Gebreyesus Brhane Tesfahunegn 1,2 *, Lulseged Tamene 3 , Paul L. G. Vlek 2 , Kirubel Mekonnen 1 1 College of Agriculture-Shire Campus, Aksum University, PO Box 314, Shire, Ethiopia 2 Centre for Development Research (ZEF), University of Bonn, Walter-Flex-Str. 3, 53113 Bonn, Germany 3 Chitedze Agricultural Research Station, International Center for Tropical Agriculture (CIAT), PO Box 158, Lilongwe, Malawi Received 5 August 2012; Revised 6 June 2013; Accepted 9 June 2013 ABSTRACT Soil quality (SQ) assessment from farmers' point of view can be used as a primary indicator for planning sustainable agriculture. Despite this fact, limited information is documented with regard to SQ indicators, for example weed species, crop types and management practices from farmers' knowledge perspectives. The aims of this study are to analyse factors that determine farmers' knowledge of SQ, identify SQ indicators of weed species and crop types across different SQ status and assess soil-and-crop management practices that maintain SQ in the Mai-Negus catchment, northern Ethiopia. Fifty-two farmer household heads were chosen randomly for questionnaire interview. The results showed significant (p ≤ 0·05) differences in the proportion of respondents who used different crop-and-soil management practices. The success of overall prediction by the logistic regression model (model χ 2 = 0·84, p < 0·01) and level of model correct predictions (86%) indicated that the explanatory variables have sufficiently explained farmers' knowledge of SQ indicators. Provided that other conditions remained constant, the odds ratio of variables such as farmer experience, access to information, farm location, education, field slope and land tenure have significantly increased the likelihood of farmers for being knowledgeable of SQ indicators. This study also demonstrated that most farmers are knowledgeable in identifying weed species, crop types and management practices across various SQ status, which suggests that such SQ indicators should be used to assess SQ status (degradation severity) while locating fields to be intervened using appropriate management strategies. © 2013 The Authors. Land Degradation & Development published by John Wiley & Sons, Ltd. keywords: soil quality status; soil quality indicator; farmers' knowledge; weed species; crop types; management practices INTRODUCTION In the past century, about 2 billion of the 8·7 billion ha of agricultural land, permanent pastures and forests and wood- lands in the world have been degraded, with the largest part being from developing countries (Chadha, 1996). However, human-induced degradation is most severe in Africa, where 30% of the agricultural land, pastures, forests and wood- lands, which are the major sources of food, income and employment, are degraded (Sheikh & Soomro, 2006). Other studies reported that about 65% of Africa's arable soils are severely degraded as a result of human-induced degradation (e.g. Sheikh & Soomro, 2006; Mairura et al., 2007). This type of degradation could be the main cause for expansion of global grain production dropped from 3% in the 1970s to 1·3% in the period 1983–1993 (Steer, 1998; Arshad & Martin, 2002). Degradation in soil quality (SQ) can be associated with the type of intensive land use, land cover changes and local knowl- edge involved in agricultural production and understanding of erosion influencing factors (Arshad & Coen, 1992; Ólafsdóttir & Júlíusson, 2000; Arshad & Martin, 2002; Mairura et al., 2007; Wei et al., 2009). In natural conditions, the soil tends to maintain equilibrium as a result of pedogenetic processes (Parr & Papendick, 1997; Masto & Chhonkar, 2008). However, this equilibrium is easily upset by human activity (e.g. poor agricultural activities), and this effect is more aggravated in arid and semi-arid regions of developing coun- tries with poor technical and financial resources. Human actions such as deforestation, soil, water and crop management prac- tices, often lead to soil unequilibrium as a result of effects on soil organic matter, soil depth, erosion, soil compaction, salini- zation, acidification, alkalinization, nutrient depletion, chemical or heavy metal contamination and/or diversity and activity of soil organisms (Masto et al., 2007; Wei et al., 2009). Such forms of soil degradation problems can pose a serious threat to national household food security (Bekele & Holden, 1999). Substantial studies suggested that degradation of soil, air and water quality have sparked interest in the concept of SQ and its assessment (e.g. Doran & Parkin, 1994; Larson & Pierce, 1994; Karlen, 2004). Although it has a variety of definitions in literature, SQ is often defined as ‘the capacity of the soil to function’ (Karlen et al., 1997). The SQ concept integrates soil biological, chemical and physical attributes to assess soil capacity to function (Doran & Parkin, 1994; Karlen et al., 1997). However, from farmers' point of view, * Correspondence to: G. B. Tesfahunegn, College of Agriculture-Shire Campus, Aksum University, PO Box 314, Shire, Ethiopia. E-mail: gebre042001@yahoo.com This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distri- bution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. © 2013 The Authors. Land Degradation & Development published by John Wiley & Sons, Ltd. land degradation & development Land Degrad. Develop. 27: 120–133 (2016) Published online 11 July 2013 in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/ldr.2233