It is very difficult to keep shmitta properly, and that is really nothing new. We know that through much of our history, including in the times of the batei mikdash, the Jewish community did not keep it properly and were punished for it. Whether we ignored it due to the difficulties, or if we created or found loopholes, perhaps we can justify it or excuse it, or at least understand it, but we should also recognize that it is not the ideal and we should strive for proper adherence to the laws of shmitta, difficult as they may be.

Easy for me to say, considering my adherence to shmitta will involve the care of a tiny patch of grass and bushes I hardly take care of anyway. And perhaps I am inconvenienced a bit in the supermarket with higher prices on vegetables or some produce that is less available. For farmers it is their life, their livelihood, their sustenance. For them it is much more difficult. And that is why those who do try to keep shmitta properly, as difficult as it will be, should be respected, and assisted, all that much more.

Gideon Saar, Minister of the Interior, announced a few days ago that he is resurrecting an old ordinance that was implemented in the days of Yitzchak Rabin's government in which the government exempted farmers who decided to keep shmitta from arnona payments for the entire year of shmitta.

To that end, the Ministry of Interior has sent letters to the various municipalities explaining the law and instructing them not to collect arnona from relevant farmers.
source: bechadrei and newspaper article

I think it is a good move. I dont know if this alone will encourage other farmers to join the list of those keeping shmitta in its entirety, but it will at least help those who do.