(a) Custom farming is the performance of services on a farm such as land preparation, seeding, cultivating, applying pesticides, and harvesting for hire with remuneration on a unit of work basis, except that, for the purpose of applying the provisions of this section, the harvesting of crops and the application of agricultural chemicals by firms regularly engaged in such businesses shall not be regarded as custom farming. A person performing custom farming shall be considered as being separate from the person for whom the custom farming is performed only if:

(1) The compensation for the custom farming is paid at a unit of work rate customary in the area and is in no way dependent upon the amount of the crop produced, and (2) the person performing the custom farming (and any other entity in which such person has more than a 20-percent interest) has no interest, directly or indirectly, (i) in the crop on the farm by taking any risk in the production of the crop, sharing in the proceeds of the crop, granting or guaranteeing the financing of the crop, (ii) in the allotment on the farm, or (iii) in the farm as landowner, landlord, mortgage holder, trustee, lienholder, guarantor, agent, manager, tenant, sharecropper, or any other similar capacity.

(b) A person having more than a 20-percent interest in any legal entity performing custom farming shall be considered as being separate from the person for whom the custom farming is performed only if:

(1) The compensation for the custom farming service is paid at a unit of work rate customary in the area and is in no way dependent upon the amount of the crop produced, and (2) the person having such interest in the legal entity performing the custom farming has no interest, directly or indirectly, (i) in the crop on the farm by taking any risk in the production of the crop, sharing in the proceeds of the corp, granting or guaranteeing the financing of the crop, (ii) in the allotment on the farm, or (iii) in the farm as landowner, landlord, mortgage holder, trustee, lienholder, guarantor, agent, manager, tenant, sharecropper, or in any other similar capacity.