ABSTRACT
Urea (U), ammonium sulfate (AS), calcium nitrate (CN) and sulfur coated urea (SCU), were applied to two alkaline soils to evaluate the effects of nitrogen (N) sources and rates on cotton lint and seed yields. The soils used in this experiment were Clareville cl (Pachic Argiustolls) and orelia c (Typic ochraqualfs). For the Clareville soil, lint yields were in the following order for the various nitrogen rates: 40 mg N kg-1 soil application: AS=U>CN>U+Fe>SCU; 80 mg N kg-1 soil application: AS>CN>SCU>U>U+Fe. For the Orelia soil, lint yields were in the following order: 40 mg N kR-1 soil application: U + Fe>AS>SCU>U>CN; 80 mg N kg-1 soil application: AS>SCU>U + Fe>U>CN. Application of N to the soil increased the average boll size. The largest boll sizes were measured when AS was applied as a nitrogen source in both soils.
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