The nitrogen content of sugarcane as influenced by moisture and age

Abstract

Moisture and age have a dominant influence on the nitrogen content of the sugarcane plant. A study of these factors revealed the following: 1. The nitrogen content of the leaf sample varied from year to year, despite constant cultural and fertilizer treatments. 2. A correction of nitrogen content for moisture eliminated the majority of the fluctuation of nitrogen in the leaf samples. 3. In most cases, leaf-sheath moisture and leaf-blade moisture gave the best correction for nitrogen variation, but rainfall variation could be used as a correction factor. 4. The nitrogen content of the leaf sample increased with increasing moisture content of the tissue; this increase was linear. 5. The nitrogen content of the leaf tissue decreased with increasing age of the cane plant. Thus a decrease in nitrogen is approximately linear to an age of about 10 to 11 months for sugarcane in Puerto Rico. After 11 months the decrease tends to level off. This relationship was also observed for Hawaiian data. 6. The factors of moisture and age appear to be the most dominant in influencing the nitrogen content of the cane-leaf sample. A correction for both moisture and age in the leaf samples taken, in many cases explained over 90 percent of the variation of the nitrogen in the sample. 7. Adjusted leaf-sheath nitrogen values were obtained from an equation using sheath moisture and age of sample. The adjusted values were in very close agreement.