Phred schreef
In other words, the yield of N in a crop was greater than the amount
fixed.

Indeed, most of the N will usually be
removed too if the crop is to have any value elsewhere.

If you harvest for pulse, hay,
whatever, you'll most likely remove most of the N that was fixed.

+ + +
I suppose this is even more true for soybeans which, after all, are grown as
a protein source, preferred because of its high protein content. It is not
like it is rice.
PvR