(1) As soon as may be after the commencement of this Act, the Administrator shall take steps to institute and shall cause to be constantly maintained, in accordance with the rules made under this Act, an inquiry into the profits of agriculture and into the value of land used for agricultural and non-agricultural purposes.
     (2) For the purpose of determining the profits of agriculture, the following matters shall be taken into account in estimating the cost of cultivation, namely:--
         (a) the depreciation of stock and buildings;
         (b) the money equivalent of the labour and supervision by the cultivator and his family;
         (c) all other expenses usually incurred in the cultivation of the land which is under inquiry; and
         (d) interest on the cost of buildings and stock, on all expenditure for seed and manure and on the cost of agricultural operations paid for in cash.