THE governor of Maine, John McKernan Jr., shut down all nonessential state services yesterday because the Legislature failed to reach agreement on a two-year $3.2 billion state budget.Governor McKernan said non-essential state services would remain closed until lawmakers agree on the biennial budget for the fiscal period that began July 1. The shutdown kept home some 10,000 state workers at the state capital in Augusta and in regional offices across the state. The departments of correction, public safety, mental health, and a few others remained open. The new budget contains several specific tax proposals, including a broad base surcharge on the state income tax. One of the major sticking points in reaching agreement is a McKernan-backed proposal on workers' compensation reform. The governor has said that must be included in the budget.