Any seah which contains a quarter [of a kav] of a different species, one should reduce [its proportion of the latter] Rabbi Yose says: one should pick [it all out]. Whether it consists of one species or of two species. Rabbi Shimon says: they said this only if it consists of one species. But the sages say: anything which is kilayim, in a seah [it adds up] in making up the quarter.

To what does this refer? To [an mixture of] grain [occurring] with [different] grain, or pulse with [different] pulse, to grain with pulse, and to pulse with grain. However they stated: Seeds from a garden which are not eaten, they add up [with other seeds to form an amount sufficient to prohibit the sowing of a seah] when there is 1/24 of the quantity [of such seed] that is necessary to sow a bet seah. Rabbi Shimon says: just as they ruled to be stringent so too they ruled to be lenient flax [mixed in with] produce, combines when there is 1/24 of the quantity [of such seed] that is necessary to sow a bet seah.

If one’s field was sown with wheat, and he changed his mind and decided to sow it with barley, he must wait until it [the wheat] rots. He turns [the soil] and then he may sow [the barley], if it [the wheat] had already grown. He should not say: “I shall [first] sow [the barley] and, then turn [the soil]” rather he must first turn [the soil] and then sow. How much must he plow [when overturning the soil]? Like the furrows [that are plowed after the [first] rainy season. Abba Shaul says: [one should plow] so that one does not leave [unplowed] as much [ground] as holds a quarter [kav] to a bet seah.

[His field was] sown [with grain, or pulse, or garden-seed], and he changed his mind and decided to plant it [with vines], he may not say: “First I shall plant [the vines] and then turn [the soil],” but he must [first] turn [the soil] and then he may plant [the vines]. [If it was] ‘planted’ [with vines] and he changed his mind and decided to seed [with grain, pulse or garden-seed], he may not say: “First I shall sow [the grain etc.] and then I uproot [the vines],” but he must [first] uproot [the vines] and then he may sow [the grain etc.] If he wants, he may cut down [the vines] to less than a handbreadth [above ground], and then he may sow [the grain] and later, he uproots [the vines].

His field was sown cumin or with arum, he must not sow on top of them, since they produce crops only after three years. [A field of] grain among which sprang up some aftergrowth woad, alternatively an area of threshing-floors in which many species sprang up, alternatively [a field of] clover among which grew up a number of species of herbs, he is not obliged to weed them out. But if he weeded or cut down the weeds, they say to him: “Uproot it all, except for one species.”

If the point of an angle of a wheat [field] overlaps into a barley [field], it is permitted because it looks like the end of his field. If his [field] is of wheat, and his neighbor’s is of another species, he may sow [next to the border] some of the same species [as that of his neighbor]. If his field was of wheat and that of his neighbor’s was of wheat, he may sow next to him a row of flax, but not a row of any other species. Rabbi Shimon says: it is all the same whether he sows flax or any other species. Rabbi Yose said: even in the middle of one's field it is permitted to check one’s field with a row of flax.

They may not sow mustard or safflower close to a field of grain, but they may sow mustard or safflower close to a vegetable field. And they may sow close to fallow land or to plowed land, or to a wall made with loose stones, or to a path, or to a fence ten handbreadths high, or to a trench ten [handbreadths] deep and four wide, or to a tree forming a tent over the ground, or to a rock ten [handbreadths] high and four wide.

One who wishes to make his field into square plots [each sown] with a different species, he should divide it into twenty-four square plots for a bet seah, a square plot per bet rova, and he may then sow in each whatever species he wants. If there is one square plot or two [inside his field], he may sow them with mustard, but if there are three he may not sow them with mustard, since it looks like a field of mustard, the words of Rabbi Meir. But the sages say: nine square plots are permitted, ten are forbidden. Rabbi Eliezer ben Yaakov says: even though the whole of his field is a bet-kor, he may not make within it more than one square plot.

Whatever there is within a bet rova [which separates different species] is included in the area of a bet rova: the space which vine roots consume, a grave, a rock, [all] count in the measure of a bet rova. [One who wants to sow one type of] grain [in a field of another type] of grain the measure is a bet rova. Vegetables within [a field of other] vegetables the measure is six handbreadths. Vegetables within [a field of] grain, or grain within [a field of] vegetables the measure is a bet rova. Rabbi Eliezer says: vegetables in [a field of] grain the measure is six handbreadths.

Stalks of grain which are leaning over other stalks of grain, or vegetable [plants] on other [] vegetable plants, or stalks of grain over vegetables plants or vegetable plants over stalks of grain, all this is permitted, except in the case of the Greek gourd. Rabbi Meir says: also in the case of the cucumber or Egyptian beans. But I recognize their words [as more acceptable] than mine.