Soil amendments which include starch-based superabsorbent polymer (SAP) particles are combined with a liquid fertilizer solution to form a flowable suspension. Methods for manufacturing the SAP liquid fertilizer suspension are disclosed. The starch-based SAP product may include a monomer graft polymerized onto a starch in the presence of an initiator to form a starch graft copolymer. Various mesh sizes of granular SAP particles may be mixed with a liquid fertilizer solution that optionally includes a micronutrient multivalent cation solution.
