(Mishnah): If one wishes to arrange his field in rows of different species - Beis Shammai say that he should make breaks between them of three furrows of newly-broken ground (i.e. 2 Amos). Beis Hillel say that they should be the width of Sharoni yokes. And these two opinions are close (in measurement).

(Gemara) (R. Zeira/ R. Elazar citing R. Chiya the Great): The Mishnah means that he should leave an area of two by two Amos at the top of each furrow, even if that distance narrows further down the furrow until it is minimal.

(R. Yona): This distance of the Mishnah is enough only when the entire field is planted in rows, but if he made one row (close to the edge of the field), it's not enough and the distance of a Beis Rova (space to plant a quarter Kav of seeds) must be kept.

This is like the statement of R. Yannai - I can sow a (Beis Seah, 50 by 50 Amos) field with 50 different species, 25 this way and 25 that way.

This would also apply to two fields (that if there were rows in one's field next to the row of one's adjacent field, one could then plant another species at a distance of only two Amos rather than a Beis Rova).

If so, even between his field and his neighbor's field, it would be permitted. And the same applies to a destroyed field (when one has strips in his field as well as a strip from a neighbor's now destroyed field).

Alternatively, it would be permitted because of the teaching of Raish Lakish, citing Chizkiyah, that a Rosh Tur that comes out of a destroyed field is permitted.

(Rebbi): (Disagreeing with R. Chiya the Great earlier) He begins the space at a size of a Beis Rova (just over 10 Amos) and he may narrow it down until it is the width of three furrows of newly-broken ground (2 Amos).

Question: Doesn't Rebbi agree that grains into grains, the width must be a Beis Rova (as we see later in Mishnah 7 (Menachos 42-1(a))?

Answer: The Mishnah is discussing squares, but here they are strips that need less separation.

Question: Do the Rabbanan not agree with Rebbi that strips need less separation?

Answer (R. Yudan): The narrow end of the space between the strips according to Rebbi is the same as the wide beginning of the space according to Rabbanan.

Question (R. Elazar): If there was a small field (that was too small for the full length space), what's the law?

Answer (R. Elazar bar Shimon/ Abba Yosi ben Yochanan of Yanoach): In a large field (more than 100 Amos in length), the space must be 50 Amos long; in a small field, it must be the majority of its length.

If these Sages, who gave a required length of the space for a large field did not give it for a small field; the Chachamim who did not give for a large field certainly would not give for a small field.