Agrochimica. Vol. LVI - N. I January-February 2012 Distribution variability of total and extractable copper in cultivated acid soils of India and their relationship with some selected soil properties S.K. BEHERA'. A.K. SHUKLA, M.V. SINGH Indian Institute of Soil Science, Nahihagh, 13erasia Road. Bhopal, 462 038, Madhya Pradesh, India Received July 21, 2011 - Received in revised ff.rm October 24, 2011 -Accepted November 10, 2011 Keywords: Acid soil, copper, distribution variability, soil properties INTRODUCTION. - In most of the soils, copper (Cu) is derived from the parent material or added to the soil through different anthropogenic activities (PIETRZAK and McPttAIL, 2004) and bound with silt and clay fractions of soil. In alkaline soils, it is mostly present in carbonate and residual fractions and in iron oxide fractions in acid soils (SHUMAN, 1991; BEHERA et al., 2009). Concentration of Cu in soil and its availabil- ity are of great agricultural and environmental importance (Wu et al., 2010). Cu is an essential plant nutrient and constituent of number of important enzymes involved in photosynthesis, protein and carbohydrate metabolism in plants. It has potential to create hazard in the environ- ment (MORENO et al., 1997). Copper deficiency is known to cause yel- lowing of young leaves, rolling and dieback of leaf tips and retardation of tillering and stunted growth (CLARK and BALIGAR, 2000). However, excess Cu supply usually inhibits root growth more than shoot growth (LEXMOND and VoRM, 1981), and causes plant toxicity. Phyto-availability of Cu in soil is dependent on soil types, climatic condition and crop management practices. Hence, there is a need to under- stand the necessary and safe copper concentrations in soils so that benefits and potential hazards can be identified. Published information regarding the critical value of total Cu concentration in Indian soils for contamina- tion is not available. However maximum loading limit of total Cu in case of Indian soils is 179 mg kg- 1 (personal communication from J.K. SAHA, IISS, Bhopal, India). Copper deficiency is common in sandy, coastal and peaty soils and soils developed on copper-poor parental rocks (CAMPBELL, 1976). Leaching and intense weathering in acid soils result in deficiency 'Corresponding author: sanjih_hls(dJrcdlffn1aiLco111 Pre-sent address: I )ircctoratc of( )ii Palin Research, Pedavcgi - 514 450, West Ciodavuri District. J\ndhra Pradesh. India