Jerusalem Talmud Bava Metzia 9:7

משנה: הַמְקַבֵּל שָׂדֶה מֵחֲבֵירוֹ לְזוֹרְעָהּ שְׂעוֹרִין לֹא יִזְרְעֶנָּה חִיטִּין. חִיטִּין יִזְרְעֶנָּה שְׂעוֹרִין. רַבָּן שִׁמְעוֹן בֶּן גַּמְלִיאֵל אוֹסֵר. קִטְנִית לֹא יִזְרְעֶנָּה תְבוּאָה. תְּבוּאָה יִזְרְעֶנָּה קִטְנִית. רַבָּן שִׁמְעוֹן בֶּן גַּמְלִיאֵל אוֹסֵר. MISHNAH: One who contracts with another for a field to sow barley shall not sow wheat; for wheat he may sow barley. Rabban Simeon ben Gamliel prohibits⁵⁵He holds that the tenant is always required to obey exactly the terms of his lease. The anonymous Tanna holds that barley may be substituted for wheat in crop rotation but not vice-versa.. For legumes⁵⁶Beans and similar vegetables whose roots enrich the soil with nitrogen. The Babli contends (107a) that in Iraq grain is more beneficial to the soil than legumes. he may not sow grain; for grain he may sow legumes. Rabban Simeon ben Gamliel prohibits.

הלכה: הַמְקַבֵּל שָׂדֶה מֵחֲבֵירוֹ כול׳. נִיחָא שְׂעוֹרִין לֹא יִזְרְעֶנָּה חִטִּים. חִיטִּין לֹא יִזְרְעֶנָּה שְׂעוֹרִין. וַתְייָא כְרִבִּי לָא אוֹ כְדִבְרֵי הַכֹּל בְּמָקוֹם שֶׁאֵין שְׂעוֹרִין כִּפְלַיִים בְּחִיטִּין. אֲבָל בְּמָקוֹם שֶׁמַּעֲלִין שְׂעוֹרִין כִּפְלַיִים בְּחִיטִּין זוֹרְעָהּ שְׂעוֹרִים. HALAKHAH: “One who contracts with another for a field,” etc. One understands that for barley he may not sow wheat⁵⁷Since wheat takes more out of the ground than does barley.; for wheat, may he not sow barley? It follows Rebbi La⁵⁸In the next Halakhah, following the reading of E. or is the opinion of everybody at a place where the yield of barley is not twice that of wheat. But at a place where barley produces twice as much as wheat he may sow barley⁵⁹Even if this interferes with crop rotation..