(30g) Nitrogen Efficient Fertilizer Materials

Nitrogen cycle management is a critical challenge in modern engineering. NH₃ synthesis from N₂ consumes several percent of total world energy while only a fraction of the synthesized fertilizer nitrogen, such as urea, is absorbed by the plants. Majority of nitrogen initially confined in urea is decomposed and released in the environment as gaseous NH₃ or soil and water mobile nitrate, NO₃^-, resulting in low sustainability nitrogen fixation process. Furthermore, for a complete plant nutrient all of the nutrients (N,P,K,Ca,Mg,S) need to be supplied in one solid granulated or liquid mixture. Aqueous liquid fertilizers are expensive to transport since their dissolved nutrient content is governed by the solubility limits.

Molecular crystals of urea with inorganic acids (H₃PO₄ and H₂SO₄) as well as solid salts (CaSO₄, MgSO₄, Ca(H₂PO₄) and Mg(H₂PO₄)) present a convenient form of high nutrient content fertilizers that can be inexpensively transported to the remote locations and applied directly or via fertigation. Importantly, these urea inorganic acid adducts have been shown to result in a much more efficient nitrogen uptake by plants combined with significantly lower nitrogen losses. The work will be presented that will explore design of these fertilizers that contribute to the enhanced sustainability of the chemical processing. In particular, mechanochemical synthesis methods that avoid use of liquid solvents that would otherwise necessitate evaporation or result in high aqueous solution transportation costs will be presented. Since dissolution of the solid urea adducts for fertigation requires in depth knowledge of the corresponding phase diagrams, these data will also be presented. Finally, molecular structure effects of the urea adducts on the improved nitrogen cycle management will be discussed as well as the synthesis of industrial and anthropogenic waste derived nitrogen efficient molecular fertilizers.