Factors influencing the production and use of beachgrass and dunegrass clones for erosion control. III. Influence of kinds and amounts of fertilizer on production

Nurseries for the production of European beachgrass Ammophila arenaria, culms should be located on eroding sand where weeds and other grasses do not offer competition. These sites are low in plant nutrients and the addition of fertilizers containing nitrogen is required. Inorganic fertilizers are much more effective than organic fertilizers for increasing the rate of production. They also give higher levels of production. The nitrogen in organic fertilizers apparently was liberated more slowly than it was in inorganic fertilizers under the cool conditions of the coast. Ammonium compounds were much more effective than sodium nitrate as inorganic sources of nitrogen. There were no significant differences between ammonium sulfate and ammonium phosphates (16-20-0) when applied to supply equivalent amounts of nitrogen. Single applications of fertilizer resulted in better production than split applications, indicating that there was no appreciable leaching of soluble nutrients through the sand, even under the high rainfall conditions of these trials. Nitrogen at the rate of 40 pounds per acre in one application and in the form of ammonium compounds gave the greatest efficiency of production. There was no evidence that 80 pounds of nitrogen gave sufficiently greater production to warrant the added cost. Applications of less than 40 pounds of nitrogen had no significant influence on production. Plantings made at dates when low survival can be expected can be improved by adding 40 pounds of nitrogen in the form of ammonium compounds. They are not improved when organic fertilizers are used due to the slow liberation of nitrogen. All nursery plantings should be made at optimum dates to insure high survival, but plantings made in the field for erosion control can be extended into seasons of moderately unfavorable conditions if nitrogen is added.