IRRIGATION SCHEDULING FOR SWEET PEPPER - Management, Performance, and Applications of Micro Irrigation Systems - page 179

Table 3 compares the Year 1 and Year 2 results of the nitrogen leaching analy-
sis. The leached nitrate and ammonium estimates were obtained from equations/5a/
and/5b/, respectively. Figure 5 shows the nitrate concentrations in the 60 - 80 cm
depth interval during the Year 1 season. During Year 1 the range of estimated nitrogen
leached was between 36 and 67 kg /ha. During Year 2, the range of estimated nitrogen
leached was between 27 and 36 kg /ha. Interestingly, the amount of nitrate lost (aver-
age of all treatments) on April 6, 2002 and April 10, 2003 was 19.6 kg /ha and 20.1 kg /
ha, respectively. For years 1 and 2 this represented 34% and 60% of the total N lost by
leaching during the two seasons, respectively. Figure 6 shows the estimated percent of
nitrogen (i.e., nitrate plus ammonium) leached relative to N applied (225 kg /ha) during
the Year 1 and Year 2 seasons for the four experimental treatments.
FIGURE 5 Year 1 Soil nitrate concentrations in the 60-80 cm depth interval. Values between
the sampling dates were obtained by linear interpolation.
FIGURE 6 Estimated nitrogen leached during the Year 1 and year 2 season. LF1 is the
Lime-Fertigation 1 treatment, LF2 is the Lime-Fertigation 2 treatment, NLF1 is the No-Lime-
Fertigation 1 treatment, NFL2 is the No-Lime-Fertigation 2 treatment.
The smallest amount of nitrogen leaching occurred in the LF1 treatment in 2002
and the NLF2 treatment during the second year. There is no clear difference between