How can I calculate the Nitrogen (N), Phosphorus (P), Potassium (K), sulfur (S), and Zinc (Zn) content in rice grain and Straw and their uptake in rice grain and straw? Moreover, could you please mention the unit of nutrient (N, P, K, S & Zn) uptake in grain and straw?
To calculate the nutrient content and uptake in rice grain and straw (for Nitrogen (N), Phosphorus (P), Potassium (K), Sulfur (S), and Zinc (Zn)):
Methodology:
Units:
- Nutrient content and uptake are in kg/ha.
- Nutrient concentration is in mg/kg.
Nutrient Measurement Techniques:
- N: Kjeldahl method
- P: Colorimetry (Molybdenum-blue method)
- K: Flame photometry or AAS
- S: Turbidimetry or ion chromatography
- Zn: Atomic absorption spectrophotometry (AAS)
By applying the formulas above and using laboratory techniques to determine nutrient concentrations, you can calculate the nutrient content and uptake in rice grain and straw.
Nitrogen (N): The total nitrogen content is usually determined using Kjeldahl or an elemental analyzer (Dumas method).
Phosphorus (P), potassium (K), sulphur (S), zinc (Zn): The samples are first digested (wet or dry), and then the contents are determined by ICP-OES/ICP-MS or spectrophotometer, flame photometer, etc. The results are commonly expressed as follows.
Measurement results are commonly expressed in the following ways:
Expressed as mass percent (%). For example, the N content of a certain seed is 1.2%, P content is 0.2%, etc.
@@Expressed in milligrams per kilogram (mg/kg) or grams per kilogram (g/kg) for trace/concentrate elements. For example, Zn is 25 mg/kg, etc.