Ammonium dihydrogenphosphate with Diammonium hydrogenphosphate, Urea and Water (IUPAC SDS Volume 66)
Evaluator
Jitka Eysseltová Department of Inorganic Chemistry, Charles University
Evaluation
6.1. Solubility in the NH4H2PO4-(NH4)2HPO4-Urea-H2O System

Many different subsystems may be selected in the NH3-H3PO4-H2O system. One of them, the ternary system NH4H2PO4-(NH4)2HPO4-H2O, is of special importance. Many studies of multicomponent systems formed by the addition of further compounds to this system have been reported. One such system, NH4H2PO4-(NH4)2HPO4-urea-H2O, has been investigated by Ivanov and Grantscharov.1-9 They studied the parts of the system where the NH3/P2O5 ratio is 1.4, 1.5, 1.6, 1.7, 1.8 and 1.9. In their reports they also included nomograms for calculating total plant food value6-9. The only other work that can be compared with the work of Ivanov and Grantscharov is the work of Kaganskiy and Babenko.10 The latter report discusses a study of the sytem where the NH3/P2O5 ratio is 1.5. The plant food values reported in Ref. 10 are given in Table I. This table also includes the plant food values calculated by using the nomograms of Ivanov and Grantscharov.4 The agreement is fairly good which indicates some validity for the nomograms of Ivanov and Grantscharov. But further independent experimental work is needed before a more detailed evaluation can be made.

Reports of studies of other multicomponent systems formed by the addition of agrochemically important components to the NH4H2PO4-(NH4)2HPO4-urea-H2O system are also available.11,12 However, no evaluation can be made of these data because of differences in the components used and in the experimental conditions that prevailed.

Sources:

1 Ivanov, D. G.; Grantscharov, I. N.; God. Vissh. Khimikotekhnol. Inst. Sofiya 1966, 13, 165.
2 Ivanov, D. G.; Grantscharov, I. N.; God. Vissh. Khimikotekhnol. Inst. Sofiya 1968, 15, 153.
3 Grantscharov, I. N.; Ivanov, D. G.; God. Vissh. Khimikotekhnol. Inst. Sofiya 1970, 15, 127.
4 Ivanov, D. G.; Grantscharov, I. N.; God. Vissh. Khimikotekhnol. Inst. Sofiya 1970, 15, 159.
5 Ivanov, D. G.; Grantscharov, I. N.; God. Vissh. Khimikotekhnol. Inst. Sofiya 1970, 15, 227.
6 Grantscharov, I. N.; Ivanov, D. G.; God. Vissh. Khimikotekhnol. Inst. Sofiya 1970, 15, 335.
7 Ivanov, D. G.; Grantscharov, I. N.; God. Vissh. Khimikotekhnol. Inst. Sofiya 1970, 15, 349.
8 Grantscharov, I. N.; Ivanov, D. G.; Miner. Torove. Nauch Tekh. Konf. 2nd 1970, 107.
9 Grantscharov, I. N.; Ivanov, D. G.; Khimiya i Industriya 1971, 14, 63.
10 Kaganskiy, I. M.; Babenko, A. M.; Zh. Prikl. Khim. 1970, 43, 2421.
11 Slack, A. V.; Hatfield, J. D.; Shaffer, H. B.; Driskell, J. C.; J. Agr. Food Chem. 1959, 7, 404.
12 Kaganskiy, I. M.; Babenko, A. M.; Izv. Obl. Neorg. Tekhnol. 1972, 69-73