Sforno on Genesis 4:11/ספורנו על בראשית ד׳:י״א

1ארור אתה מן האדמה, cursed and deprived of the good the earth has to offer.

2אשר פצתה את פיה, because it allowed itself to be used to cover up the killing of your brother. As a result, earth will no longer be free to provide the needs of your livelihood in the degree it did up until now. There was no need to spell out the penalty for the murderer. His punishment is part of the principle applying to the penalty for anyone causing willful damage, i.e. he will experience tit for tat as spelled out in Leviticus 24,19.