Survey on fertility status of cotton growing soils of Guntur district in Andhra Pradesh

摘要

Survey and analysis of 100 soil samples of nine different mandals in Guntur district was carried out to assess an overall picture of physico chemical properties and fertility status of the cotton growing soils of Guntur district. Soil samples were analysed for pH, B.C., O.C., ammonical form of nitrogen, available phosphorus, potassium, magensium and zinc. The pH, E.C. and O.C. of the soils ranged from 7.54-8.69, 0.095-3.25 dSm~(-1) and 1900-9700 ppm with a mean value of 8.16, 0.37 dSmin~(-1) and 6700ppm, respectively. Available P, K, Zn and ammonical form of nitrogen were found to be in the range of 4.60-20.33, 73.54-372.2, 190-2400, 0.6-3.4 and 33.8-180 ppm with an average of 7.82, 230.75, 1089, 1.70 and 92.26 ppm, respectively. In general, the soils were alkaline in reaction having low to high O.C. Available P, K, Zn in medium to high range and ammonial form of nitrogen was in low to medium range. Soil organic carbon and available phosphorus exhibited medium nutrient indicates, while available potassium and zinc exhibited high nutrient indices. Therefore, judicious fertilization of N, P and micronutrients was required for sustainable cotton production.