Income tax computation with net agricultural income affects aggregate tax liability and triggers surcharge and withholding adjustments. The section prescribes tax rates and mechanisms for charging income-tax, TDS, TCS and advance tax, and provides a specific computation method for net agricultural income: aggregate total and agricultural income to determine tax at applicable rates, separately increase agricultural income by a fixed base and compute tax as if that were total income, then reduce the aggregate tax by that amount to yield the tax on total income. It also requires surcharge additions in specified cases and supplies definitions of key terms for these computations.