Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You didn't learn this reading yet, so here's a mnemonic to help you:
You need to till your land because you want to have a tiger yard (たがや). That's either when you have a yard full of live tigers, or you plant bushes and shape them into tigers. I hope it's the second kind of tiger yard. Either way, you have to plow the land to get it ready.
I’ll plow the field with this machine.