The Necessity of Application of Frequency Electric Drives for Irrigation Systems A.B. Kaidar, B.K. Shapkenov, V.P. Markovsky, A.P. Kislov and A.O. Borzykh E3S Web Conf., 288 (2021) 01002 Published online: 14 July 2021 DOI: 10.1051/e3sconf/202128801002