# Applying nutrients to vegetables via irrigation

Page last updated: Friday, 2 September 2016 - 9:33am

Please note: This content may be out of date and is currently under review.

## Nutrient applied

As an example, the total nitrogen applied to a vegetable crop from irrigation water is 14kg/ha/week if 10mm of irrigation water with a nitrogen concentration of 20mg/L is applied every day for a week (that is, 70mm of irrigation water per week). This figure is shown in bold in Table 1.

Table 1 Nutrient applied (kg/ha) to vegetables based on applied irrigation (mm) and nutrient concentration (mg/L). The first row shows concentration of nutrient in mg/L.

Water applied

(mm)

1 5 10 15 20 25 30
1 0.01 0.05 0.10 0.15 0.20 0.25 0.30
5 0.05 0.25 0.50 0.75 1.00 1.25 1.50
10 0.10 0.50 1.00 1.50 2.00 2.50 3.00
15 0.15 0.75 1.50 2.25 3.00 3.75 4.50
20 0.20 1.00 2.00 3.00 4.00 5.00 6.00
25 0.25 1.25 2.50 3.75 5.00 6.25 7.50
30 0.30 1.50 3.00 4.50 6.00 7.50 9.00
35 0.35 1.75 3.50 5.25 7.00 8.75 10.50
40 0.40 2.00 4.00 6.00 8.00 10.00 12.00
45 0.45 2.02 4.50 6.75 9.00 11.25 13.50
50 0.50 2.50 5.00 7.50 10.00

12.50

15.00
55 0.55 2.75 5.50 8.25 11.00 13.75 16.50
60 0.60 3.00 6.00 9.00 12.00 15.00 18.00
65 0.65 3.25 6.50 9.75 13.00 16.25 19.50
70 0.70 3.50 7.00 10.50 14.00 17.50 21.00

Note: Milligrams per litre (mg/L) equals parts per million (ppm).

For a 10-week crop, the total amount of nitrogen applied from the irrigation water will be 140kg/ha. The rate of fertiliser nitrogen applied to the crop should be reduced by the amount calculated for the life of the crop (in the example, 140kg N/ha).

Ian McPharlin