All figures quoted should be considered as a typical product analysis and may vary.
- A white granular / prilled product.
- Particle size distribution of granular product typically ranges from 2.0 – 5.0mm.
- Critical Relative Humidity @ 30°C: 72.5%
- Solubility at 20°C: 108g / 100ml of water.
- 46% Nitrogen (N).
- N in the Ammine (NH2) form and is not available for plant uptake.
- NH2 is converted to NH4+ through the urease reaction.
- Acidification index: 3.57 kg pure lime/kg N or 1.64 kg pure lime per kg urea applied.
- Salt index: 75 (relative to Sodium Nitrate @ 100).
- Biuret (NH2-CO-NH-CO-NH2) may be formed by polymerization at high production temperatures.
AGRONOMIC BENEFITS & CAUTIONS
- Urea is the most widely used N source in agriculture.
- It is the cheapest source of N and due to its higher concentration additional savings may be made on application and logistics costs.
- Urea is readily soluble and may be put through irrigation systems.
- Urea N is not immediately available for plant uptake.
- NH2 must first be converted to ammonium before it can be taken up by plants.
- Ammonium doesn’t leach due to its positive charge.
- Urea in solution carries no electrical charge and is prone to leaching.
- Leached urea will lead to sub soil acidification and eutrophication of dams and rivers.
- Urea is best washed into the soil through rainfall or irrigation or incorporated to prevent volatilization losses.
- Application of urea to a soil surface covered with plant residue could increase volatilization due to urease in the plant residue.
- Avoid application of urea to recently limed soil surfaces as the alkalinity from the lime could cause volatilization.
- Urea is compatible for blending with Mono Ammonium Phosphate, Ammonium Nitrate and Potassium Chloride.
- Avoid mixing urea with nitrates or nitrate containing mixtures to prevent NPK blend quality problems.
- Biuret levels >1.5% may lead to toxicity especially when foliar feeding.
- Although feed grade urea is used in animal feeds as source of non-protein nitrogen, caution should be taken to prevent spillages and contamination with drinking water as excess urea is toxic and will cause in mortality in livestock.
Please note: Consult a qualified person (Act 36 of 1947) for specific applications / recommendations.