SOIL FERTILITY STATUS OF MULBERRY (MORUS ALBA L.)SOILS UNDER BIVOLTINE SERICULTURAL AREAS OF NORTH, SOUTH AND EASTERN REGIONS OF KARNATAKA.

Abstract

Soil analysis based prescription to suitable amelioration of mulberry gardens for enhanced quality leaf and bivoltine cocoon production is the priority of sericulture industry in Karnataka. With the above objective in the present study a total of 2067 composite soil samples were collected from traditional sericultural vicinity under 13 districts situated in North (1066), South (855) and Eastern (146) parts of Karnataka and subjected for their chemical analysis. The soil samples were characterized and analysed for their soil type, reaction (pH), salinity (EC) and nutrient status like available nitrogen (N), phosphorous (P), potassium (K), sulphur (S) and boron (B), respectively. The soils received were observed to be 52% were loamy (clay), 28% red, 12% black and 8% lateritic indicating that large numbers of soils are most suitable for mulberry cultivation. In regard to the soil reaction and salinity status, 59% of the soils showed desired optimal category of pH (6.5-7.5) for mulberry, 18% acidic (<6.5) and 23% were of very high pH (>7.5). Electrical conductivity (EC) was normal with desirable soil salinity in 99% soils indicating congenial for mulberry (<1.0dS/m 2). Organic carbon (OC) was low (<0.65%) in 76% soils, 23% desirable range (0.65-1.0%) whereas negligible number of soils showed higher OC content (>1.0%) alarming that maximum soils were falling under low fertility category. Available Nitrogen (N 2 O) and Phosphorous (P 2 O 5) was recorded low (<250kg/ha; <15kg/ha) in 98% and 45% samples. Medium level (15-25kg/ha) of, P 2 O 5 was recorded in 23% soils and higher side (>25kg/ha) in 32% samples. Optimal range (120-240kg/ha) of available Potassium (K 2 O) was recorded in 49%, low (<120kg/ha) in 20% and 31% soil showed high level (>240kg/ha). Available Sulphur (S) was recorded high (>15ppm) in 54% soils followed by 41% desired level (10-15ppm), whereas mere 5% soils shown low level (<10) of sulphur. In case of available Boron (B) 44% soils recorded as low (<0.5ppm), 43% are desired level (0.5-1.0), whereas 13% soils exhibited high content of available Boron