Why did president lincoln reject the crittenden compromise?

The “Crittenden Compromise,” as it became known, included six proposed constitutional amendments and four proposed Congressional resolutions that Crittenden hoped would appease Southern states and help the nation avoid civil war. The compromise would have guaranteed the permanent existence of slavery in the slave states by reestablishing the free-slave demarcation line drawn by the 1820 Missouri Compromise. Though Crittenden’s plan drew support from Southern leaders, its rejection by many Northern Republicans, including President-elect Abraham Lincoln, led to its ultimate failure.

The answer is crop yield.