In two studies conducted by
researchers at North Carolina State University (NCSU), Nitamin®
Steady-Deliverytm liquid fertilizer from Georgia-Pacific improved
tomato yield, fruit size and overall crop quality when compared to
the traditional practice of quick-release fertilization with sodium
nitrate.
Nitamin, developed by scientists at Goergia-Pacific, is a slowly-available
nitrogen source that delivers the Optimal Nitrogen Diettm to crops.
Unlike commonly used quick-release fertilizers that convert most of
their nitrogen to useable forms within the first few weeks, the patented
Nitamin Steady-Delivery fertilizers deliver nitrogen to crops at a
rate that they can effectively utilize throughout the growing cycle,
while minimizing nitrogen loss through leaching and volatilization.
In comparison studies between Nitamin and quick-release fertilizers
with sodium nitrate, led by NCSU researchers Drs. Doug Sanders and
Luz Reyes, Nitamin liquid fertilizer improved tomato yield and quality
when injected into a drip irrigation system at lower rates and with
fewer applications compared to the standard practice of weekly injections
with quick-release fertilizer.
“When we compared the plots, the Nitamin tomato plants had greater
growth, better color and higher overall plant quality,” says
Sanders.
In the studies conducted at NCSU’s horticulture crops research
stations in Clinton and Fletcher, N.C., Nitamin resulted in higher
fruit and plant weights at lower nitrogen application rates, demonstrating
higher nitrogen use efficiency. Both trials demonstrated that Nitamin
liquid fertilizer could be front-loaded, over the first six weeks
after planting, and satisfy the season long N needs of the plants.
“Normally this approach would not be practical for nitrate-based
fertilizers since leaching could be an issue,” according to
Jim Wargo, Georgia Pacific technical service agronomist.
In the Clinton study, Nitamin applied at 200 pounds of (N) per acre
(a) produced the highest yields of any treatment, yielding 416 more
marketable boxes per acre than the same amount of sodium nitrate and
91 more boxes than the highest amount of sodium nitrate (300 lb. N/a).
Nitamin applied at 150 lb. N/a produced total marketable yield equivalent
to the 200 and 300 lb. N/a from sodium nitrate treatments even though
25 – 50 percent less nitrogen was applied. Sanders’ calculations
for gross dollar return showed that Nitamin would have resulted in
a higher return of $970 to $4563 per acre over the two sodium nitrate
treatments.
At Fletcher, Nitamin applied at 175 and 250 lb. N/a produced over
1000 more marketable boxes per acre than either of the standard sodium
nitrate treatments of 200 and 300 lb. N/a The heavier fruit load on
the Nitamin fertilized plants resulted in one additional harvest compare
to the standard treatments. While no differences were found between
treatments in the amount of jumbo tomatoes produced, Nitamin (at both
rates) resulted in higher yield of extra large, large and medium-size
tomatoes. Furthermore, there was no advantage to increasing the Nitamin
rate above 175 lb. N/a, suggesting more efficient nitrogen utilization
at lower rates. The 43 percent increase in marketable yield with Nitamin
showed the potential for higher gross dollar return per acre compared
to sodium nitrate.
Other University research studies in Illinois, Alabama and the eastern
shore of Virginia have shown that Nitamin continues to deliver a steady
supply of nitrogen to plants throughout the growing season, even after
long periods of heavy rains.
