-2-

of the soil fe utility as it was at sampling and as it will likely
be in the fore eeable future would be a helpful tool, especially
if the analysis can be done easily and quickly. This is assuming
no excess lea thing occurs. With this in mind, trials were
conducted in which one of the goals was to find the most reliable
procedure which also produces the most useful results. Remember
that these soil tests are only for cultural systems in which all
of the fertiliz r is applied prior to mulching and one-half of the
fertilizer mixt re is slow-release nitrogen (sulfur coated urea,
IBDU, osmocote, etc) and one-half is soluble nitrogen (NH4NO3,
urea, KNO3, (NH )2S04, etc).

 MATERIALS AND METHODS

Since nitrogen 's usually the most limiting nutrient because of
leaching, it wa the only nutrient varied in the trials. Nitrogen
fertilizer deri ed from sulfur coated urea and ammonium nitrate
was applied at ates of 100 and 200 lbs nitrogen/acre the first
year with 'Tufts' and 'Dover' cultivars. The second year
'Chandler' plants received 67, 133, and 200 lbs nitrogen/acre.
Phosphorus was a plied at 50 lbs/acre as P 0 and potassium at 200
lbs/acre as K2 each season. During both seasons beds were
fumigated with m thyl bromide chloropicrin (MC-2) at 400 Ibs/acre
and mulched wi h black polyethylene. Plants were set in
mid-October eac season. Fruit were harvested twice weekly
through April, g aded, counted, and weighed.

To determine the best method of soil sampling from the plant bed,
three methods we e used. These methods included: a) 5 soil cores
equally spaced a ross the bed with one core coming from fertilizer
band, b) soil co es that included the fertilizer band and adjacent
4 inches on either side, and c) a cross-section across the entire
bed, the width f the section was about one inch wide. All
samples were tak n to a depth of 7 inches. Saturated extracts
were obtained and the electrical conductivities determined. These
values were then correlated to the fertilizer rate and the plant
fruiting response The cross-section method of sampling gave the
consistent results.

Samples were take from each replicate at plant establishment, at
fruit harvest, at mid-season, and near end of season in April.
Saturated extract were obtained from the soil samples, and the
electrical condu tivities were determined. The electrical
conductivities gi e a measure of the soluble salts present soil
(See Table 1). T ese are generally expressed in millimhos/cm. A
saturated extract from a sandy moist soil with a reading of one
millimhos/cm is e ual to about 1400 ppm of soluble salts in the
soil