1、Real

To measure NPK, three approaches are used: electrical conductivity testing, optical techniques, and electrochemical methods. These measurements are generally performed in a centralized laboratory.

2、Current sensor technologies for in situ and on

These sensor technologies can measure soil total nitrogen (TN) and soil mineral nitrogen (SMN), respectively, with high accuracy under laboratory conditions, despite less accuracy is to be expected under both the in situ and on-line measurements modes.

3、Review on Detection Methods of Nitrogen Species in Air, Soil and

Here, we review the recent advancements in optical and electrochemical sensing methods for measuring nitrogen concentration in the air, soil, and water. We have discussed the advantages and disadvantages of the existing methods and the future prospects.

Total nitrogen estimation in agricultural soils via aerial

To address this challenge, we develop an artificial intelligence (AI)-driven near real-time unmanned aerial vehicle (UAV)-based multispectral sensing solution (UMS) to estimate soil TN in an...

Method evaluation in total Nitrogen in solid fertilizers

Following an IFA internal membership request, the IFA Method Harmonization Working Group embarked on the process of identifying methods for recommendation as best practice on determination of Nitrogen content for nitrogen containing solid fertilizers.

How To Measure Nitrogen In Fertilizer

Learn how to accurately measure nitrogen content in compound fertilizers using the Kjeldahl method with our comprehensive guide. We focus on assessing nitrate-N, the most plant-accessible nitrogen form, through soil tests to gauge existing nitrogen levels.

(PDF) A Review on Soil Nitrogen Sensing Technologies: Challenges

This paper systematically analyzes and summarizes soil nitrogen detection methods by compiling and analyzing the relevant literature, comparing the advantages and disadvantages of various...

Soil Nitrate Measurement for Determination of Plant

Nitrate concentration in soil is a good indicator of available nitrogen to plants. The required soil nitrate-nitrogen (NO 3 -N) for specific crops varies from crop to crop but in general, a concentration range of 10-50 mg/kg is desired.

Point

Here we demonstrate that point-of-use measurements of NH 4+, combined with soil conductivity, pH, easily accessible weather and timing data, allow instantaneous prediction of levels of NO 3− in...

Estimating soil nitrate leaching of nitrogen fertilizer from global

In this study, we conducted a meta-analysis to estimate the nonlinear response of nitrate leaching to N application rates using the ΔEF method developed by Shcherbak et al. (2014) to characterize the nonlinear N 2 O response to N input.

The concentration of nitrogen fertilizer is a critical indicator in agricultural production, directly affecting crop growth and yield. Accurate measurement of nitrogen fertilizer concentration is essential for improving fertilizer utilization efficiency, reducing environmental pollution, and achieving sustainable agricultural development. The following methods outline how to measure nitrogen fertilizer concentration:

1. Prepare Tools and Equipment

• Electronic balance: For precise measurement of sample mass.
• Volumetric flask or burette: For accurate preparation of standard solutions and titration experiments.
• Beaker, glass rod, dropper, etc.: For dissolving, diluting, or transferring liquids.
• pH meter: To determine solution acidity/alkalinity, indirectly reflecting nitrogen fertilizer concentration.
• Ammonia absorption apparatus: For measuring ammonia content in fertilizers.
• Thermometer: To record temperature changes during experiments and eliminate temperature-related biases.

2. Sample Preparation

• Take a specific amount of the nitrogen fertilizer sample (typically ~50 grams).
• Place the sample in a beaker, add an appropriate amount of water, and stir thoroughly to ensure complete dissolution.

3. Prepare Standard Solutions

• Select standard solutions (e.g., 0.01 mol/L, 0.1 mol/L) based on the expected concentration range.
• Weigh the required amount of standard solution using an electronic balance and dilute with deionized water to the desired volume.

4. Titration Experiment

• Fill a burette with deionized water and adjust it to the appropriate scale.
• Use a glass rod to mop up the sample solution and add it to the burette.
• Observe and record phenomena during titration, such as color changes or bubble formation.
• At the endpoint, note the volume of standard solution consumed.

5. Calculate Nitrogen Fertilizer Concentration

• Determine the moles of nitrogen in the sample based on titration results.
• Since nitrogen fertilizers often exist as ammonium salts, calculate concentration using: [ ext{Concentration (mol/L)} = frac{ ext{Moles}}{ ext{Volume (L)}} ]

6. Calibration and Verification

• If using an ammonia absorption apparatus, indirectly assess concentration by measuring ammonia content.
• Validate accuracy and reproducibility by comparing titration results with standard solutions of known concentrations.

7. Precautions

• Avoid introducing contaminants (e.g., iron ions) that may interfere with measurements.
• Ensure all glassware is thoroughly cleaned and sterilized to prevent microbial contamination.
• Wear appropriate personal protective equipment (PPE), such as gloves and goggles, during experiments.

8. Data Analysis

• Analyze titration data and calculate nitrogen concentration using the formula above.
• Compare measured results with theoretical values to evaluate experimental accuracy and reliability.

By following these steps, nitrogen fertilizer concentration can be measured with reasonable accuracy. note that different types of nitrogen fertilizers may require adjustments based on their specific properties. Additionally, modern agricultural technologies have introduced faster detection methods, such as High-Performance Liquid Chromatography (HPLC) and Atomic Absorption Spectroscopy (AAS), which offer higher sensitivity and precision for rapid, large-scale testing.