Jerusalem Talmud Bava Batra 1:2

משנה: וְכֵן בַּגִּינָּה מְקוֹם שֶׁנָּהֲגוּ לִגְדּוֹר יִגְדּוֹר. אֲבָל בַּבִּקְעָה מְקוֹם שֶׁנָּהֲגוּ שֶׁלּא לִגְדּוֹר אֵין מְחַייְבִין אוֹתוֹ אֶלָּא אִם רוֹצֶה כּוֹנֵס לְתוֹךְ שֶׁלּוֹ וּבוֹנֶה וְעוֹשֶׂה חָזִית מִבַּחוּץ. לְפִיכָךְ אִם נָפַל הַכּוֹתֶל הַמָּקוֹם וְהָאֲבָנִים שֶׁלּוֹ. וְאִם עָשׂוּ מִדַּעַת שְׁנֵיהֶם בּוֹנִים אֶת הַכּוֹתֶל בָּאֶמְצַע וְעוֹשִׂין חָזִית מִכָּאן וּמִכָּאן. לְפִיכָךְ אִם נָפַל הַכּוֹתֶל הַמָּקוֹם וְהָאֲבָנִים לִשְׁנֵיהֶן. MISHNAH: Similarly for a vegetable garden¹⁵An irrigated area of intensive agriculture.; a place which customarily is fenced in, he must fence in¹⁶If one of the parties wishes to construct a fence the other party is forced to contribute land and money to its construction.. But in an agricultural area¹⁷בקעה is a region of extensive agriculture., a place which customarily is not fenced in, one does not obligate him. But if he¹⁸One of the farmers. wishes, he builds inside his land and makes a façade¹⁹A smooth face; the wall or fence must be covered with smooth stone plates. This characterizes the fence or wall as private property of a single owner. to the outside; therefore if the wall collapses both land and stones are his.
But if they²⁰Two property owners in the agricultural area. did it with mutual agreement they build the wall in the middle and make façades on both sides; therefore if the wall collapses⁵If a wall collapsed and it is no longer known who built it, one has to assume that it was built following these rules. both land and stones belong to both of them.

הלכה: וְכֵן בַּגִּינָּה כול׳. תַּנֵּי. בַּגִּינָּה בֵּין מָקוֹם שֶׁנָּהֲגוּ לִגְדּוֹר בֵּין מָקוֹם שֶׁנָּהֲגוּ שֶׁלֹּא לִגְדּוֹר כּוֹפִין. אֲבָל בַּבִּקְעָה מָקוֹם שֶׁנָּהֲגוּ לִגְדּוֹר כּוֹפִין. שֶׁלֹּא לִגְדּוֹר אֵין כּוֹפִין. HALAKHAH: “Similarly for a vegetable garden,” etc. It was stated: For a vegetable garden, whether it be a place where it is customary to build a fence, or a place where it is not customary to build a fence, one forces²¹As pointed out in the Babli, 4a, Mishnah 2 is ambiguous in the case of a place where it is not customary to fence in vegetable gardens. From the first sentence, one would infer that one would not force one farmer to participate in the costs of a fence which his neighbor wants to put up, but from the second sentence it seems that only in agricultural areas he does not have to participate. The Babli restricts the power of the court to order participation in the building of a fence to places which do not have a declared policy against erecting fences. It is possible to read this into the Yerushalmi text.. But in an agricultural area, at a place where it is customary to build a fence one forces; where it is not customary to build a fence one does not force.