Status and Distribution of Silicon in Soils Under Dominant Cropping Systems of Northern Karnataka and Response of Rice Oryza sativa L to Silicon Application in Acid Soil of Uttar Kannada District

Abstract

An investigation was undertaken to study the Status and forms of silicon in soils newlineunder dominant cropping systems of Northern Karnataka. Fourteen profile samples and newlinethirty surface soils from two depths were collected from selected seven dominant cropping newlinesystems of Northern Karnataka. Six major pools of silicon were estimated in soils using newlinesequential extraction procedure. The pools of Si were in the order of residual Si gt amorphous newlineSi gt occluded Sigt organic Si gt adsorbed Si gt mobile Si. The mobile and adsorbed were the newlinesmallest pools ranging from 0.023 to 0.043 and 0.031 to 0.052 g kg-1, respectively and newlineresidual was the largest pool (31.04 to 48.24 g kg-1). The available silicon status was found newlinelow when extracted with calcium chloride (lt109 mg kg-1) but high (gt47 mg kg-1) with acetic newlineacid . newlineField experiments were also carried out at KVK, Sirsi to study the Response of rice newlineto silicon application in acid soil of Uttar Kannada District during kharif 2018 and 2019. The newlineexperiment consisted of nine treatments viz., two soil and two foliar application rates and their newlinecombinations. The results revealed that, soil application of silicon at 200 kg ha-1 + foliar newlineat 0.5 per cent recorded significantly higher growth parameters and yield parameters viz., newlinenumber of grains per panicle (121.33), test weight (23.64 g), grain yield (5750 kg ha-1) and newlinestraw yield (6960 kg ha-1) besides lower per cent disease incidence. Finally, it can be newlineconcluded that application of silicon at 200 kg ha-1 soil+ 0.5 per cent foliar seems beneficial newlinefor profitable rice production in soils of zone 9 of Karnataka. newline