Orlah and aeroponics

The posekim discuss the question of terumot and ma'aserot when growing sprouts employing misting/spraying. Rabbi Yaakov Ariel and his son, Rabbi Azriel Ariel, exempt such sprouts from terumot and ma'aserot (HaTorah VeHa'aretz IV, 5759); while Rabbi Mordechai Eliahu does not (HaTorah VeHa'aretz III, 5757). The lenient opinions rely on the phrase "tevu'at zarecha," "the produce of what you sow" (Devarim 14:22). Sowing is in soil; even those who liken water media to soil may not necessarily view air as such. Moreover, the Yerushalmi exempts produce grown indoors from terumot and ma'aserot, since a house is not a "field." Even if we obligate produce grown indoors in light of produce grown in the field, no such gezeirah of Chazal applies to aeroponics.

Orlah laws work differently: the term aretz, "land," is used, and not sadeh, "field" (as we explained previously); thus orlah applies even to trees grown indoors and in unperforated pots.

Rabbi Shlomo Amar and Rabbi Yehuda Amichay discuss orlah and aeroponics for pitaya trees; both agree that orlah applies (Techumin 26, 5766). Aeroponics has since become a standard cultivation technique throughout the world.

In practice:

As I wrote previously, aeroponic cultivation is new and I haven't found any posekim who relate to it outright. I was asked this question by a Gush Etzion resident and the rabbis of Torah VeHa'aretz Institute discussed it in Tevet 5779.

Rabbi Yehuda Amichay, head of Torah VeHa'aretz Institute, rules that aeroponics are to be treated like hydroponics, and therefore such trees are subject to orlah miderabanan—at least for private cultivation.

How wonderful when new questions arise in light of global technology and living in Israel!