(a) The term “employment” does not include services performed by an individual under an arrangement with the owner or tenant of land pursuant to which—

(1) Such individual undertakes to produce agricultural or horticultural commodities (including livestock, bees, poultry, and fur-bearing animals and wildlife) on such land,

(2) The agricultural or horticultural commodities produced by such individual, or the proceeds therefrom, are to be divided between such individual and such owner or tenant, and

(3) The amount of such individual's share depends on the amount of the agricultural or horticultural commodities produced.

(b) If the arrangement between the parties provides that the individual who undertakes to produce a crop or livestock is to be compensated at a specified rate of pay or is to receive a fixed sum of money or a stipulated quantity of the commodities to be produced, without regard to the amount actually produced, as distinguished from a proportionate share of the crop or livestock, or the proceeds therefrom, the services performed by such individual in the production of such crop or livestock is not within the exception.

(c) For provisions relating to the status, under the Self-Employment Contributions Act of 1954, of the services which are excepted from “employment” under this section, see the regulations under section 1402(a) in Part 1 of this chapter (Income Tax Regulations).