Show I Soil Needs Nitrogen I How lime clover and crop resi resi- residues residues residues dues increase the soils soil's nitrogen and organic matter supply and thus boost crop yields is shown by the chart below This drawing summarizes summarIzes su izes results of tests at the DIxon soil soU experiment field by University of Illinois agronomists All three plots in the tests were limed and the crop rotation on each included corn oats and wheat One plot had hadDo no Do clover The small grain straw was removed and the cornstalks were burned This plot produced a a I year four average of 57 bushels per acre The second plot had the same Y UMENO UME-NO CLOVER CORNSTALKS BURNED COON 57 CON BU au jM g I SWEET CLOVER CORNSTALKS TAU S BURNER CORN 81 CON A 8 I EU BU UME SWEET LIME SWEET CLOVER aWER CORNSTALKS OATS CAT l AND WHEAT EAT STRAW PLOWED UNDER CORN 69 RJ BU iW IA m treatment except that sweet clover was seeded in the wheat and plowed under as a green manure crop for corn The increased nitrogen and organic matter from the clover boosted the corn com yield 24 bushels On the third plot sweet clover was I grown and in addition the corn cOrn- cornstalks cOrnstalks cornstalks stalks oats straw and wheat straw I were returned to the soil The extra organic orga c matter nitrogen and other plant foods thus saved and returned In the crop residues gave the soil soU I what it takes to yield 88 bushels of corn com per acre |