Reference for Bava Metzia 202:2

בשדה מ"ט משום ישוב א"י איכא דאמרי משום כחשא דארעא מאי בינייהו איכא בינייהו חוצה לארץ:

they are granted. Why so in the case of a field? — For the sake of the cultivation of Palestine. Others say: Because of the impoverishment of the soil.<span class="x" onmousemove="('comment',' The plants, in drawing their sustenance from the soil, have impoverished it, and the owner of the field is entitled to some compensation. ');">²</span>

Jastrow