Response to Silicon Fertilization by Paddy in Typic Ustochrept (Goradu) Soils of Middle Gujarat

Preliminary survey work was carried out in paddy growing area of Anand and Kheda district of middle Gujarat to know the available silicon (Si) status in soils of paddy fields. Total sixty surface soil samples were collected and categorized as per available Si status in low, medium and high categories. Representative bulk soil samples were taken to conduct pot experiment to study the available Si and response to Si application by paddy in goradu soils of middle Gujarat. The soils were treated with four levels of Si viz., 0, 100, 200 and 300 mg Si kg soil^-1. The experiment was planned in factorial completely randomized design with three repetitions. The Si application up to 200 mg kg^-1 soil significantly increased grain and straw yields of paddy over control under low (< 25 mg Si kg^-1 soil) and medium (25-50 mg Si kg^-1 soil) category soils, while it was up to 100 mg Si kg^-1 soil in high category soils. The further addition of silicon i.e. 300 mg Si kg^-1 soil showed a declining trend. Si content in grain was significantly increased under medium and high categories of soils as compared to low category soils. The highest Si content in grain (2.74 %) was recorded in soils having high status of available Si i.e. high category soils. The Si content in straw was significantly increased at Si₁₀₀, Si₂₀₀ and Si₃₀₀ levels over control (5.94 per cent). The Si uptake by paddy grain and straw was significantly affected by Si levels in low and medium soil categories as compared to high category soils.