Coastal Mudflat Saline Soil Amendment by Dairy Manure and Green Manuring

Dairy manure or green manuring has been considered as popular organic amendment to cropland in many countries. However, whether dairy manure combined with green manuring can effectively amend mudflat saline soil remains unclear. This paper was one of first studies to fill this knowledge gap by investigating impact of dairy manure combined with green manuring on soil chemical properties of mudflat saline soil. Dairy manure was used by one-time input, with the rates of 0, 30, 75, 150, and 300 t ha−1, to amend mudflat saline soil. Ryegrass, Sesbania, and ryegrass were chosen as green manures for three consecutive seasons, successively planted, and tilled, and maize was chosen as a test crop. The results indicated that one-time application of dairy manure enhanced fertility of mudflat saline soil and supported growth of ryegrass as the first season green manure. By the cycles of the green manuring, it rapidly improved the chemical properties of mudflat saline soil by decreasing soil salinity and pH and increasing soil organic carbon and available N and P, which promoted growth of maize. Dairy manure combined with green manuring can be applied for mudflat saline soil amendment, which provides an innovative solution for mudflat saline soil reclamation, dairy manure disposal, and resource recycling.