So, the real key is probably the addition of organic matter . Any type of organic matter will be beneficial - from compost to commercial peat . Organic matter will not only aid retention of added fertilizer, but will retain moisture and make coastal soils less droughty. Fertilizers containing minor elements like iron, copper, zinc, etc., often need to be applied to the soil in coastal areas. Screens of plant materials can be used to reduce wind and sand damage, thus making the site better to growing plants.
Salt adversely affects plants in two ways.
Excess salts in the soil greatly reduce the water uptake by plants. Even if the soil has plenty of water, little may be available to plants if too many salts are present. Secondly, salts can be directly toxic to plants. Put some table salt on a wet blade of grass, and you'll see what salt-burn looks like. Salt spray will produce a characteristic scorched or burned appearance on leaves and leaves will eventually drop off the plant.