Meadow
Grassland
noun
Grass covering the earth is a meadow. Or, if you're less creative, it's grassland.
The reading is a combination of kun'yomi and on'yomi readings. That being said, both readings for both kanji are the readings you learned with the kanji so you should be able to read this.
草地の上に大きな木があった。
There was a large tree on the grassland.
アイルランドにはたくさんの草地があります。
Ireland has many grasslands.
どこか草地でピクニックしませんか?
Would you like to picnic on the grassland somewhere?