not advisable to apply these fertilizer materials on a soil surface that may 

 be subject to wave and tidal action. Considered convenient because they 

 require fewer applications, these materials may permit lower rates, partic- 

 ularly of nitrogen, and may have a larger carryover effect into the succeeding 

 growing season. Although slow-release fertilizers are much more expensive 

 than conventional fertilizers, in some cases they produce better results than 

 less costly soluble sources (Broome, Seneca, and Woodhouse, in preparation, 

 1983). 



2. Placement of Fertilizer . 



Broome, Seneca, and Woodhouse (in preparation, 1983) found surface appli- 

 cation (topdressing) to be ineffective, even of soluble materials on a compact 

 sandy, clay loam soil in the planting year. Evidently, the nutrients did not 

 penetrate rapidly enough and a root mass was not available soon enough to 

 absorb them. Surface application on cohesive sediments is also likely to be 

 ineffective during the first year. The most effective placement of fertilizer 

 in the year of establishment on all soils is probably in the planting hole or 

 furrow. This allows the nutrients to be close to the developing root systems 

 and minimizes losses from surface runoff and erosion. However, the intimate 

 mingling of soluble fertilizers with the plant roots may pose a danger of salt 

 damage in compact or cohesive sediments, even though these plants possess a 

 high tolerance to salt. To avoid this problem soluble materials should be 

 broadcast and disked in prior to planting, spread in the planting furrow, 

 placed in a second hole beside the planting hole, or placed in the bottom of 

 the planting hole and covered with soil before the plant is inserted. Salt 

 damage can be a problem, even in the absence of fertilizer, on marsh plants 

 growing on sites subject to extended periods of low water caused by wind 

 setdown or reduced streamflow (Woodhouse, 1979). Placement in the planting 

 hole should be limited to slow-release materials in these situations and in 

 planting high marsh species. 



Surface application of soluble fertilizer materials is effective on loose 

 sandy soils in the planting year (Woodhouse, Seneca, and Broome, 1976). How- 

 ever, application of fertilizers to the soil surface should be delayed for a 

 month or so after transplanting to allow transplants to develop new roots. 

 Such topdressing is done on the exposed surface during low tide. Surface 

 application of soluble fertilizers is very effective on established marsh. 

 Broome, Seneca, and Woodhouse (in preparation, 1983) found that even where the 

 surface application of fertilizer at planting was ineffective, a topdressing 

 the following spring doubled aboveground biomass by the end of the growing 

 season. The extensive root systems, together with the dense aboveground 

 growth, combined to retain much of the fertilizer. Fertilizer that was not 

 initially absorbed would have soon been covered by accumulating sediments. 



3. Fertilizer Rates . 



The rate of application of fertilizers on marsh plantings for shoreline 

 erosion control should be high enough to insure that nutrient supply will not 

 be a limiting factor in the rapid establishment of transplants. The cost of 

 such fertilizer will be low in relation to the total cost of the planting and 

 even lower in relation to the cost of failure. For this reason, if fertiliz- 

 ers are to be used, they should be applied at ample rates, but not excessively 

 or in wasteful amounts of nutrients. 



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