HERBICIDES WITH EXTENDED SOIL LIFE

Herbicidally active thiolcarbamates are employed in combination with certain allyl amine salts of thiocarbamic acid compounds having the formula wherein R4 and R5 are independently selected from the group consisting of allyl, alkyl substituted allyl, and lower alkyl groups having from about 1 to about 6 carbon atoms; R6 and R7 are independently selected from the group consisting of allyl, alkyl substituted allyl, and lower alkyl groups having from about 1 to 6 carbon atoms; and X is oxygen or sulfur wherein at least one of R4 and R5 and at least one of R6 and R7 is an allyl group. In a typical application, the allyl amine salt of thiocarbamic acid compound is included in sufficient quantity to lessen the rate of soil degradation of the thiolcarbamate. As a result, the herbicidal effectiveness of the thiolcarbamate is enhanced and prolonged, rendering single application of the herbicide effective over a longer perod of time.