1、Fate of nitrogen in agriculture and environment: agronomic, eco

For world’s sustainable food production and atmospheric benefits, there is an urgent need to up-grade nitrogen use efficiency in agricultural farming system. The nitrogen use efficiency is the product of nitrogen uptake efficiency and nitrogen utilization efficiency, it varies from 30.2 to 53.2%.

2、Recent advances in the chemistry of nitrogen, phosphorus and potassium

This necessitates the study of the major mineral fertilizer elements (nitrogen (N), phosphorus (P), and potassium (K)), the forms in which they are applied to soil, and their chemistry/reactions in soil.

3、nitrogen in fertilizer

Nitrogen is taken up by the plant in two different forms, NH 4 (ammonium) and NH 3 (nitrate). The forms of nitrogen in most fertilizers are either ammonium nitrate (N 2 H 4 O 3) or urea (CO (NH 2) 2), or a combination of the two.

4、Fertilizer Materials and Soil Nutrient Amendment

The relative content of chemical elements nitrogen (N), phosphorus (P), and potassium (K) commonly used in fertilizers is labeled using NPK rating and any additional chemical labeling follows after that. The N value is the percentage of elemental nitrogen by weight in the fertilizer.

5、Nitrogen and the future of agriculture: 20 years on

Nitrogen transformation inhibitors and other N fertilizer “stabilizers” applied to broadacre crops account for the bulk of that market, whereas controlled- and slow-release fertilizers are mostly applied to high-value crops such as turf, ornamentals, nurseries and plantations.

Elemental Analysis: NCS Characterization of Fertilizers

This paper presents data of different solid and liquid fertilizer samples analyzed several times. Liquid samples were homogenized by a ball mill while liquid samples were analyzed without pre-treatment.

An Overview of Nitrogen, Phosphorus and Potassium: Key

Various types of fertilizers containing essential elements are now being added to agricultural lands for betterment of yield. This chapter is an attempt to highlight the various aspects of three essential macroelements required by the plants, namely nitrogen (N), phosphorus (P) and potassium (K).

Valence and Oxidation State: A Comparison of Their Value and

Valence and oxidation state are two longstanding models that each remain effective ways of organizing and rationalizing the chemistry of the elements.

Plant Nutrition Part 2

This is not totally true because most chemical fertilizers use urea (CH4N2O) as a source of nitrogen. In the presence of water and urease (an enzyme found in plants, bacteria, fungi, and some invertebrates), urea is digested to yield ammonium (NH4 +) and carbon dioxide (CO2).

Fertilizers: Nitrogen Fertilizers

The amount of total nitrogen loss from fertilizers containing urea due to ammonia volatilization can vary considerably, from 10 percent loss to 50 percent or more of the applied nitrogen, especially if the soil pH is above 7.0.

Nitrogen fertilizers are commonly used in agricultural production, with nitrogen (N) as their primary component. The valence of nitrogen refers to the charge it carries when forming chemical bonds with other atoms in compounds. The difference between the valence of nitrogen in fertilizers and elemental nitrogen arises primarily from their distinct chemical environments.

First, nitrogen fertilizers are chemical substances containing nitrogen as their main ingredient. In these fertilizers, nitrogen exists in ionic forms, leading to valences of +1 or -3. For example:

• In urea (NH₄HCO₃), nitrogen has a valence of -3;
• In ammonium nitrate (NH₄NO₃), nitrogen exhibits valences of -3 (in NH₄⁺) and +5 (in NO₃⁻);
• In diammonium phosphate (NH₄H₂PO₄), nitrogen has a valence of -3. These examples illustrate that the valence of nitrogen in fertilizers depends on its specific chemical context.

Second, elemental nitrogen itself can exhibit multiple valences. According to the periodic table, nitrogen can form compounds with valences of -3, +3, +4, +5, or 0. For instance:

• In nitrogen gas (N₂), nitrogen has a valence of 0;
• In ammonia (NH₃), it is -3;
• In nitric acid (HNO₃) or nitrate salts (e.g., NaNO₃), it is +5. This variability shows that the valence of nitrogen depends on its chemical environment.

Why does the valence differ between nitrogen fertilizers and elemental nitrogen? The key lies in their environmental differences. Nitrogen fertilizers are chemicals where nitrogen predominantly adopts valences of +1 or -3 due to ionic bonding. In contrast, elemental nitrogen’s valence varies widely based on its compound. For example:

• Elemental nitrogen (N₂) has a valence of 0;
• Ammonia (NH₃) features -3;
• Nitrate ions (NO₃⁻) display +5. These cases confirm that the valence of nitrogen in fertilizers correlates with its chemical surroundings.

Additionally, the valence of nitrogen in fertilizers relates to its concentration. Generally, fertilizers with higher nitrogen content tend to have valences closer to 0 (like elemental nitrogen), as abundant nitrogen atoms stabilize bonds. Conversely, lower-concentration fertilizers may favor ionic forms, deviating from 0.

the valence disparity between nitrogen fertilizers and elemental nitrogen stems from their chemical environments. While fertilizers typically involve ionic nitrogen with valences of +1 or -3, elemental nitrogen’s valence is highly variable depending on its compound. Concentration also plays a role in determining the valence of nitrogen in fertilizers.