  In this paper we study 1+1 field generalization of the rational $N$-body
Calogero-Moser model. We show that this model is gauge equivalent to some
special higher rank matrix Landau-Lifshitz equation. The latter equation is
described in terms of ${\rm GL}_N$ rational $R$-matrix, which turns into the
11-vertex $R$-matrix in the $N=2$ case. The rational $R$-matrix satisfies the
associative Yang-Baxter equation, which underlies construction of the Lax pair
for the Zakharov-Shabat equation. The field analogue of the IRF-Vertex
transformation is proposed. It allows to compute explicit change of variables
between the field Calogero-Moser model and the Landau-Lifshitz equation.
