570.4  Limitation on lien in case of crop failure.
  In cases of farm leases involving the rental of farmlands of forty acres or more, where the tenant has defaulted in the payment of the rent and suit has been commenced aided by landlord’s attachment for the enforcement of the landlord’s lien, the defendant may file as a defense that the default or inability to pay is caused or brought about by reason of drought, flood, hail, storms, or other climatic conditions or infestation of pests affecting the crops in controversy. When such a defense has been filed, the issue as to the cause for the default shall be triable as an equitable action. Upon the hearing, if the court finds that the default or inability to pay is due to drought, flood, hail, storm, or other climatic conditions or infestation of pests affecting the crops in controversy, the court may enter a decree pursuant thereto with the court’s finding of fact. Where a decree has been entered finding that the inability to pay was brought about by any of the conditions named in this section, the landlord’s lien shall be confined to all of the crops grown and raised upon the premises and to all increase in livestock and hogs raised upon the premises.
  The provisions of this section shall not apply to any farm leases executed prior to July 4, 1941.
[C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §570.4]