1 - ESTABLISHMENT

Paspalum absorbs very little N during the first month after planting. The grass prioritises root development. Medium to high levels of P and K are essential for rhizosphere development, especially in salt-affected environments. Basic fertilisers with ratios of 1:2:3 (N:P:K) or 1:3:4 are adequate during this period. Rates of 2.5g per 100 sq. metres (0.33-0.50 lbs./1000 sq. ft.) biweekly for the first month are adequate if P and K soil levels are medium to high.

2 - GROW-IN

Normal grow-in from sprig planting is 2-3 months, depending on sprig volume and water quality. An aggressive "bermuda-grass fertility program" will escalate the grow-in.

About 4 weeks after planting when stolons become visible from the initial sprigs, a complete fertiliser (i.e., 2:1:3, 1:1:2, 1:2:2, or 1:1:1 N-P-K) should be applied at 0.5kg per 100 sq. metres (1 lb./1000 sq. ft.) Soil temperatures should be >12.8C (55F) and pH >5.5 for maximum conversion of NH4+ to NO3-.

Repeat fertiliser applications every 2-3 weeks until grow-in is 90% complete.

Enhance grow-in by verticutting or slicing, beginning at weeks 5 or 6. Apply 2.5-5.0 g per 1 sq. metre (0.50 -1 lb./1000 sq.ft.) of a highly soluble nitrate source i.e., Ca (NO3)2 and irrigate. Repeat on 14-day cycles, verticutting in different directions each time.

If the site is sodded, fertilisation is the same as for the initial stolon establishment and for the second treatment at 4 weeks.

If salt-laden water is used for irrigation, higher than normal levels of P and K plus micronutrients may be needed due to high leaching volumes. Using highly soluble nitrate sources can also be beneficial.

3 - MATURE TURF

The Seashore paspalums developed nutrient uptake and utilisation mechanisms which provide functional growth and development under very low nutrient availability and severe nutrient imbalance situations. In general, SeaIsle 1 has lower nutrient requirements and a higher efficiency uptake system than bermudagrass or other warm season grasses. Adjust the ferility program to account for nutrients supplied by the irrigation water.

NITROGEN

Paspalum will not take up NH4+ Nitrogen or urea Nitrogen directly. These compounds must be transformed to NO3- Nitrogen prior to paspalum uptake (soil temperature > 12.8C or 55F and pH>5.5).

If the soil pH <5.5, a lime addition can enhance microbial conversion of NH4+ Nitrogen or urea Nitrogen to NO3- Nitrogen.

Fertilisation schedules for paspalum are essentially a cool-season grass regimen. For salt-affected sites with high leaching needs, use the higher rate. For non-salt-affected sites, use the lower rates. Fields that are frequently used will require more frequent spoon feeding applications to enhance recovery:      - Moderate amounts (0.25-0.49 kg N/100 sq. m or 0.50-1.0 lb./1000        sq.ft.) in the Spring and Autumn months.      - Minimal monthly amounts (0.16-0.32 kg N/100 sq. m or 0.33-0.66        lb. N/1000 sq.ft.) during the high heat times of summer.

Optimum annual N rates range from 1-2 kg actual N /100 sq. metres (2-4 lb. N/1000 sq.ft.). Compared to hybrid bermudagrasses, this amounts to 50 - 60% less N fertiliser annually in many environments.

Avoid high N rates going into winter months to minimise succulence and predisposition to cold temperature injury. Early to mid-autumn applications can range from 0.25-0.38kg per 100 sq. metres per month (0.50 - 0.75 lb./1000 sq. ft.).

If paspalum is overseeded with a cool season grass in the Autumn, avoid high N applications until the paspalum is completely dormant, otherwise the paspalum may remain vigorous with a high growth rate and become more succulent.

Balance quick release N sources (rapid uptake, enhanced recovery from injury) with slow release sources in a spoon-feeding approach.

Balanced fertilisers (i.e., 10-10-10, or 19-19-19, N-P-K) can be used in 0.125 -0.5kg per 100 sq. metres (0.25-1.0 lb./1000 sq. ft.) increments monthly from March to June and September to November in the northern hemisphere.

Excess chloride in irrigation water can suppress the uptake of N

POTASSIUM

Sufficient K must be supplied to paspalum on a regular schedule. Avoid exceptionally low levels in the soil. Potassium is essential for wear tolerance and stress tolerance, especially salinity/salt tolerance.

In salt-challenged environments, excess Na can suppress K uptake. High volume leaching to enhance net downward movement of salts will deplete the soil of K - it is one of the most mobile nutrients.

At least 3 - 8% K should be maintained on soil CEC sites.

On salt-affected fine-textured soils, 0.41 - 0.82 kg K/100 sq, m (1-2 lbs. K2O/1000 sq.ft.) may be needed on a 2 - 4 week schedule.

Apply K at 1.5 - 2.0 times the N rate (i.e., N:K2O ratios of 1:1.5 to 1:2.0 or N:K ratios of 1:1.25 to 1:1.66).

High rates (0.41-0.82 kg K/100 sq. m or 1-2 lbs. K2O/100 sq. ft.) should be applied during mid-Autumn to enhance winter hardiness.

K levels should be maintained at high levels all year, especially when poor quality effluent is used for irrigation.

Phosphorus

Moderate to high levels of P should be available during establishment and grow-in. P enhances root system development.

On salt-affected sites when constant leaching is used to flush excess salts downward and away from the root system:     - Increase annual rates by 25 - 50% to adjust for leaching losses.     - Light, frequent applications (3 - 6 applications annually).

Iron

Paspalum responds to Fe amendments and rates of * 0.5kg per 100 sq. metres (1 lb./1000 sq. ft./) per application on a monthly basis should be supplied during the growing season.

Micronutrients

In salt-challenged environments with high leaching rates, Mn, Ca, Mg, and Fe should be closely monitored for deficiencies.

In non-salt affected environments, paspalum may need applications of Na as a micronutrient (rock salt, Na-based broad spectrum micronutrient sources) when using potable water.