NUTRIENTS High quality fruit and vegetable production requires nutrient application designed to meet the specific needs of each crop at each ranch.

Plants require 18 essential elements to support growth and healthy development. While plants obtain carbon, oxygen, and hydrogen from air and water, the remaining 14 essential nutrients must be absorbed in ionic form from the soil solution. Nutrient availability depends on many factors including pH, soil texture, soil structure, and climate.

Growers can identify and predict nutrient deficiencies by monitoring soil nutrient availability and comparing the results to leaf tissue analyses. Tri-Tech works with growers and local laboratories to diagnose crop fertility requirements and find the appropriate fertilizers and soil amendments to maximize yield.

Elements From Air and Water

Hydrogen
Carbon
Oxygen

Macronutrients

Nitrogen
Potassium
Calcium
Magnesium
Phosphorus
Sulfur

Micronutrients

Chloride
Iron
Boron
Manganese
Zinc
Copper
Nickel
Molybdenum
Cobalt

The Nitrogen Cycle

  1. N is added to the soil through biological N fixation, when bacteria living in legume roots convert atmospheric N2 to ammonium. Other N sources include synthetic and organic N fertilizer, plant residue, acid rain, and atmospheric deposition.
  2. Ammonification: Microbes convert organic N into ammonium
  3. Nitrification: Soil microorganisms convert ammonium to nitrate in a two step process. First, bacteria in the group Nitrosomonas convert ammonium to nitrite. Second, Nitrobacter strains of bacteria convert nitrite to nitrate. Both steps of nitrification require oxygen. Crops benefit from nitrification because they are usually adapted to using nitrate as their main source of nitrogen. Although plants can also absorb ammonium, nitrate is often more convenient because it is mobile in soil solution and moves toward roots with the flow of water.
  4. Immobilization: When the soil organic matter’s carbon to nitrogen ratio is high, microbes incorporate ammonium and nitrate into their bodies. Microbial populations act as long term storage for soil nitrogen, making it available again when the organisms die and decompose.
  5. Ammonium adsorbs to clay surfaces
  6. Nitrate and ammonium are taken up by the plant
  7. Excess nitrate leaches down the soil profile to pollute groundwater.
  8. Denitrification: When oxygen is unavailable, the soil loses nitrogen as microbes convert nitrate (NO3) first to nitrite (NO2), then to nitric oxide (NO), nitrous oxide (N2O), and dintrogen (N2 ) gases which move out of the soil and into the atmosphere. Nitrous oxide is a particularly potent green house gas that remains in the atmosphere for over 100 years.

The N cycle describes the processes governing nutrient availability, plant growth, and environmental quality. Plants, along with all other life, require N to grow, but over 99% of the Earth’s N is held unavailable in the atmosphere, as N2 gas (Tisdale, et al. 8th Edition). Mineral N in soil comes from decomposing organic matter, synthetic N fertilizer, and when legumes are planted, N is added to the soil through bacterial N2 fixation. Nitrogen losses in agricultural systems include plant N uptake and crop harvest, temporary microbial N immobilization, nitrate leaching, erosion, and ammonia volatilization. Understanding the nitrogen transformations will help prevent damage to the environment and human health.

Using the N cycle as a model, Tri-Tech helps growers predict crop N requirements and availability throughout the season. By creating crop N budgets, managers can apply the appropriate type of fertilizer at the right rate, time, and place to meet growth requirements. Management practices aimed at reducing nitrogen fertilizer applications and improving nutrient use efficiency will prevent ground and surface water pollution while helping the grower save money on fertilizer costs and achieve increased returns.

To learn more about Nitrogen fertilizer options read this blog:

Blog Link:

Comparing Nitrogen Sources: Fates of Ammonium, Nitrate, and Urea Fertilizer in Soil

 Applying the right amount of nitrogen fertilizer is critical to fruit and vegetable production. Apply to much and plants produce excess foliage and delay fruit production. Apply too little and the crop’s overall growth will […]

...read more