Abstract: A soil conditioning composition of extended useful life in soil comprises a substantially linear, substantially water-soluble hydrophilic polymer having a molecular weight greater than 50,000 and at least one functional group disposed along the polymer chain. The polymer chain comprises one or more polymer chain segments characterized by an absence of the functional group therein and a minimum length, the minimum length of the polymer chain segment being at least one micrometer when the polymer chain segment is secured to one of the functional groups only at one end thereof and at least two micrometers when the polymer chain segment is secured to a respective one of the functional groups at each end thereof. The functional group is more capable of attaching the polymer to a solid soil phase than is the polymer chain segment, whereby the polymer includes at least one portion adapted to secure the polymer to a solid soil phase and at least one portion adapted to extend into an aqueous soil phase.