Fertilizing Chile Fields

Seedling

Flowering

Harvest

Choose nitrogen amount for this stage:

10 lb/ac	20 lb/ac	40 lb/ac

Total nitrogen lb/ac applied to field this year:

This interactive begins with green chile seedlings on a field. Depending on how much nitrogen fertilizer is given at each stage, the plants will grow well and produce plentiful fruit, grow well but yield stunted fruit, or grow poorly with a low yield. If they are given too much nitrogen, this will pollute the nearby river.

Use the slider to add more nitrogen to the soil

yield

3.4 ton/acre

nitrogen in soil

40 lb/ac

Water Pollution

50 ppm NO⁻
₃

How much nitrogen fertilizer should you add

Best value for chile pepper yield is 150, so after that point, then start showing increasing water contamination and wastefulness.

Yield

One strategy for pursuing profitable yields while avoiding water contamination is to only apply the amounts of nitrogen that will be used by the growing crop.

This can be accomplished by using analytical techniques that monitor nitrogen levels and, thus, avoid insufficient or excessive nitrogen fertilizer applications.

Soil nitrogen

A level of 20 parts per million (ppm) nitrate-N in the topsoil is a good starting point for most crops; this is equivalent to about 40 lb/ac in the upper 6-7 inches of soil.

Here’s how that’s calculated:

1 acre has 43,560 square feet.
Soil depth is about 6.5 inches or 0.54 ft
Assume an average bulk density of 84.24 lb/ft³
(based on 1.35 g/cc x 62.4 lb/ft³ per 1 g/cc)

43,560 ft² x 0.54 ft x 84.24 lb/ft³ = 1,987,643 lb/ac, which we round up to 2,000,000 lb/ac or 2 million lb/ac.

As stated previously, 20 parts per million (ppm) nitrate-N is a good starting point. So to convert to lb/ac:
20 lb/million lb x 2 million lb/ac = 40 lb/ac.

Soil calculation

1 acre has 43,560 square feet.
Soil depth is about 6.5 inches or 0.54 ft
Assume an average bulk density of 84.24 lb/ft³
(based on 1.35 g/cc x 62.4 lb/ft³ per 1 g/cc)

43,560 ft² x 0.54 ft x 84.24 lb/ft³ = 1,987,643 lb/ac, which we round up to 2,000,000 lb/ac or 2 million lb/ac.

As stated previously, 20 parts per million (ppm) nitrate-N is a good starting point. So to convert to lb/ac:
20 lb/million lb x 2 million lb/ac = 40 lb/ac.

Water Pollution

Nitrogen is the plant nutrient most likely to contaminate ground and surface waters. The nitrate form of nitrogen (NO₃⁻) is especially prone to causing contamination when excessive amounts are applied to crops.

This molecule is weakly held by soil particles and, therefore, is highly mobile in the soil. This allows excess nitrate to move readily into groundwater or with surface runoff. The result can be water pollution.

Water with a nitrate concentration above 45 parts per million (ppm), or above 10 ppm nitrate-N, is considered unsafe for drinking. [US EPA]