Boyd’s Bible Dictionary:

Much cultivated by the Hebrews (Ex. 9:31; Lev. 27:16; Deut. 8:8; Ruth 2:7). Used for bread chiefly among the poor (Judg. 7:13; 2 Kings 4:42; John 6:9-13); and for fodder (1 Kings 4:28). Barley harvest preceded wheat harvest (Ruth 1:22; 2:23; 2 Sam. 21:9-10).

Concise Bible Dictionary:

The well-known cereal, which was used as food for horses (1 Kings 4:28); and also for the food of man when wheat failed.
At the famine of Samaria, when the Syrian camp was found deserted, one measure (seah) of fine flour was sold for a shekel, and two seahs of barley for a shekel, (2 Kings 7:1, 16), showing that barley was valued at half the price of wheat. In Revelation 6:6, when scarcity is foretold, one choenix of wheat will be sold for a denarius, and three measures of barley for a denarius. Here it is one-third the value of wheat, and 5 pints will cost about 8d., which in New Testament times was a man’s daily wages.
In the trial of jealousy an offering was made of barley meal, without oil or frankincense, (Num. 5:15). It was a domestic sorrow, that never ought to occur; but if the sin was there it must be judged. In Judges 7:13 Gideon hears himself compared to a cake of barley bread: he would not have heard this had he not been afraid (Judg. 7:10); but it the more showed him whose hand must give the victory. Israel is charged with having polluted God among His people for “handfuls of barley and for pieces of bread” (Ezek. 13:19); as it says elsewhere, they had sold themselves for naught.
It was with five barley-loaves and a few fishes that the Lord fed the five thousand (John 6:9-13). Such loaves are still the bread of the poorest in Palestine. Barley is sown in October as soon as the ground is softened by the rains, and the harvest is in April, but extends to May in the colder districts.

From Manners and Customs of the Bible:

1 Kings 4:28. Barley also and straw for the horses and dromedaries.
Barley was the usual fodder for cattle. They were also fed with a mixture of chopped straw, barley, beans, and pounded date kernels.