CROP SCENE INVESTIGATION 23 SOLVED: Why did Arthur’s soybeans get ‘the streaks?’

by BERNARD TOBIN

The streaks in Arthur’s soybean field were caused by the high levels of straw in the manure that he applied randomly on the field before planting soybeans.

Generally, manure makes a positive contribution to a soybean crop. But the excessive levels of straw in Arthur's manure, and the heavy rate of application, caused a high carbon (C) to nitrogen (N) ratio, which actually starved the soybean plants of N.