SUDHIR, K.ANANTHAKUMAR, M. A.2017-03-022017-03-022011-08-06Th-9890http://krishikosh.egranth.ac.in/handle/1/5810003599An investigation was carried out during 2008–10 in the major coffee growing areas of Chikmagalur and Hassan districts of Karnataka to know the “Soil properties and dynamics of major nutrients as influenced by shade trees, rainfall and nutrient management in coffee growing areas of Karnataka”. Representative surface soil samples were collected during pre_ and post monsoon seasons from low, medium and high rainfall areas under mixed and mono shade estates and were analyzed for physical, chemical and biological properties. A piezometer study was also conducted in different locations taking into consideration the shade effects, rainfall effects and the depth of soil to know the nutrient leaching losses. Soil samples were also collected during pre and post monsoon seasons from different depths in the vicinity of piezometer installations to know the distribution of various forms of nitrogen, phosphorus and potassium contents. The results of soil properties revealed the soil pH, organic carbon, available nitrogen; phosphorus and potassium contents were higher under mixed shade in comparison to mono shade. Whereas soil organic carbon, available nitrogen and potassium contents were higher in high rain fall areas as compared to low rain fall areas; on the contrary P was higher in low rain fall as compared to high rain fall areas. The leaching loss of major nutrients was relatively higher under mono shade than under mixed shade and in medium rain fall regions than in high or low rain fall regions. The active fractions of carbon i.e. microbial biomass carbon, water soluble carbon and light fraction carbon were higher in pre monsoon than in post monsoon and were higher under mixed shade than under mono shade and, also higher under high rain fall than under low rain fall areas, irrespective of soil depths. The amounts of total and fractions of major nutrients viz., nitrogen, phosphorus and potassium contents were higher under mixed shade pattern than under mono shade pattern.ennullThesis