(Rav Zvid): If Reuven made a Chazakah in the trees, and Shimon made a Chazakah in the land, each acquired what he was Machazik in. (Rashbam - Levi sold his land to Reuven and Shimon; Tosfos - Reuven and Shimon each claim 'I bought this field'.)

Question (Rav Papa): If so, Reuven does not own any land. Shimon can tell him to uproot his trees (when they dry up; Tosfos - perhaps, immediately) and leave!

(Rav Papa): Rather, Reuven acquired the trees and half the land (Rashbam - perhaps this means, the land needed for them; Tosfos - only the area of the stumps), and Shimon acquired the rest of the land.

The following is obvious. If Levi sold his land but not his trees, he kept land (for the sake of the trees) for himself;

Even R. Akiva says that one sells generously only when he retains a pit or water cistern for himself (he does not retain a path for himself unless he specifies), for these do not harm the surrounding land, and the buyer will not tell him to remove them;

Trees harm the surrounding land. If he did not keep land for himself, the buyer would tell him to uproot them (when they dry up).

R. Akiva and Chachamim argue about one who sold trees (Rashbam - two; Tosfos - at least three) but kept the land;

R. Akiva says that one sells generously, and he sold also land (for the sake of the trees);

Chachamim say that one sells stingily, and he kept all the land for himself;

Even Rav Zvid (who said that when Reuven made a Chazakah in the trees, and Shimon made a Chazakah in the land, each acquired what he was Machazik in) could say that R. Akiva admits there, but argues here;

There, Shimon can say 'just like I got only land, you got only trees.' Here, Levi sells generously (at his own expense).

Even Rav Papa (who said that Reuven acquired also land) could say that here, Chachamim argue and say that the buyer gets no land;

There, the seller sold everything. We should not assume that he was generous to one and stingy to the other. Rather, he was generous to both;

Here, the seller kept land for himself. We assume that he was stingy and sold only the trees.

(Chachamim of Neharde'a): If one ate the Peros of 30 trees (end of 35b) that are spaced more densely than normal, this is not a Chazakah (for the extra trees are destined to be uprooted).

Objection (Rava): If so, how is one Machazik in a patch used to grow fodder (which is seeded very densely? Here also, he will uproot some!)

(Rava): If one sold trees spaced more densely than normal, the buyer does not receive land.

(R. Zeira): Tana'im argue about this law.

(Mishnah - R. Shimon): If the rows of vines in a vineyard are less than four Amos apart, this is not considered a vineyard;

Chachamim say, it is a vineyard. We view the extra vines as if they were uprooted.