The Relationship of Mineral Nutrients to Growth of Spartina alterniflora in North Carolina: II. The Effects of N, P, and Fe Fertilizers

Abstract

Abstract The effect of nutrient supply on the productivity of S. alterniflora was evaluated by applying fertilizer materials to plots in natural marshes and on S. alterniflora seeded and transplanted on dredge spoil. In a marsh growing on a sandy substrate, additions of N alone increased yields of aboveground shoots significantly, and when P was also added, the yield increased about threefold. In a marsh growing on finer textured sediments, N fertilizer doubled the yield of short S. alterniflora , but there was no response to P. There was no growth response to applications of Fe. The results indicate that primary productivity of some S. alterniflora marshes is limited by the availability of N. When N is added, lack of P may become the factor limiting growth, particularly when the substrate is coarse in texture. Lack of N is apparently one of a combination of factors which is responsible for producing the short form of S. alterniflora . Applications of N and P fertilizers also enhanced growth of seedlings and transplants which were artificially established on dredge spoil. Fertilization may be beneficial in propagating S. alterniflora salt marsh on dredge spoil since establishing a full vegetative cover rapidly is important. Response of seedlings or transplants to fertilizer would depend on the inherent fertility of the substrate material.