Do I pay the full drip cost first or only my share, how does payment work?

There are broadly two payment models and which one applies depends on your state. In the first, the subsidy is adjusted at the point of sale: the empanelled vendor bills you only your farmer share, and the department pays the subsidy portion directly to the vendor after verification, so you never have to arrange the full amount. In the second, you pay the full cost to the vendor up front and the subsidy is later reimbursed to your bank account after the system is installed and field verified, which means you need the whole sum in hand and then wait for the refund. Knowing which model your state follows matters for your cash planning, so ask the empanelled vendor clearly before you sign and, better, confirm it on the state micro irrigation portal rather than relying only on the agent. In either model the subsidy is released only after verification, and only on the approved cost norm, not necessarily your full bill, so any amount above the norm is yours regardless. Confirm the current payment model, the cost norm, and the empanelled vendor list on your state portal before committing.