; and operation and maintenance of aircraft, $911,399,000, to remain available until September 30, 2025, of which up to $18,748,000, to remain available until expended, shall be for the purposes, and in the amounts, specified for this account in the table titled Community Project Funding in the report accompanying this Act: Provided further, That appropriations hereunder shall be available pursuant to 7 U.S.C. 2250 for construction and improvement of buildings and public improvements at plant materials centers, except that the cost of alterations and improvements to other buildings and other public improvements shall not exceed $250,000: Provided further, That when buildings or other structures are erected on non-Federal land, that the right to use such land is obtained as provided in 7 U.S.C. 2250a . CORPORATIONS The following corporations and agencies are hereby authorized to make expenditures, within the limits of funds and borrowing authority available to each such corporation or agency and in accord with law, and to make contracts and commitments without regard to fiscal year limitations as provided by section 104 of the Government Corporation Control Act as may be necessary in carrying out the programs set forth in the budget for the current fiscal year for such corporation or agency, except as hereinafter provided. Federal crop insurance corporation fund For payments as authorized by section 516 of the Federal Crop Insurance Act ( 7 U.S.C. 1516 ), such sums as may be necessary, to remain available until expended. Commodity credit corporation fund REIMBURSEMENT FOR NET REALIZED LOSSES (INCLUDING TRANSFERS OF FUNDS) For the current fiscal year, such sums as may be necessary to reimburse the Commodity Credit Corporation for net realized losses sustained, but not previously reimbursed, pursuant to section 2 of the Act of August 17, 1961 ( 15 U.S.C. 713a–11 ): Provided, That of the funds available to the Commodity Credit Corporation under section 11 of the Commodity Credit Corporation Charter Act ( 15 U.S.C.