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 Agronomy Research Report AY-92-05
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 Rye or Crimson Clover and N Fertilizer MaWagement-to-Op-timize Corn
 Ear Leaf Area, Dry Weight, and N Concentration


 Aaron B. Henderson and Raymond N. Gallaher
 Participant in Student Science Training Program and Professor of
 Agronomy, respectively, Agronomy Department, Inst. Food and Agri.
 Sci., University of Florida, Gainesville, FL 32611.


 ABSTRACT
 Growth and nutrition of corn (Zea mays L.) are dependent upon
 having a sufficient area of the leaves in relation to the land on
 which they are growing. Nitrogen nutrition and management schemes
 influence the corn plant's leaf area, and subsequently, growth and
 yield. Ear leaf N concentration, area, and weight will benefit if
 cover crops [crimson clover (Trifolium incarnatum L.) and rye
 (Secale cereale L.)] and specific management schemes are utilized.
 The objective of this research was to determine the best management
 practice (BMP) of using rye or crimson clover and N fertilizer to
 optimize corn ear leaf area, dry weight and N concentration. Each
 cover crop is manipulated under each different management scheme
 which includes the type of tillage (no-tillage vs. conventional)
 and the amount of applied inorganic N fertilizer. The corn plants
 on each separate plot were analyzed by picking the top ear leaf off
 five plants and determining the total leaf area, dry weight, and N
 concentration. Under clover management, no-tillage mulch was
 proposed to be the most economical requiring only 57 kg N/ha to
 meet the sufficiency level of 2.70% N required for healthy corn.
 Under rye, no-tillage mulch was found to be the BMP based on
 expected economics as well as conservation benefits. Too little N
 and improper management will result in reduced corn yield, reduced
 production for export sales, loss of profits, waste of resources,
 and inefficiency. Too much N again results in inefficiency as well
 as potential ground water pollution. If corn could be produced in
 its ideal conditions with minimum tillage and N application,
 resources would be maximized and efficiency increased with less
 labor and less expense.