Main content area

Effective Rates of Fertilization for Correcting Manganese Deficiency in Soybeans

Mascagni, H. J., Cox, F. R.
Agronomy journal 1985 v.77 no.3 pp. 363-366
Glycine max, deficiency diseases
Manganese deficiencies occur in soybeans (Glycine max L.) grown on slightly acid to alkaline soils in the Atlantic Coastal Plain and efficient, effective corrective measures are needed. The optimum rate of Mn needed is not well defined for any method of application. Field studies were conducted to establish the most efficient rate for broadcast and band methods of soil application and for foliar application. The best time to begin foliar spraying and the number of sprayings required were also determined. Manganese sulfate was the Mn source. Manganese rate treatments for the broadcast, band, and foliar applications ranged from 0 to 90, 0 to 13, and 0 to 2.2 kg Mn ha⁻¹, respectively. Optimum yields were obtained with broadcast Mn applied at 14 kg Mn ha⁻¹ and band applications of 3 kg Mn ha⁻¹. For foliar applications, rates as low as 0.1 kg ha⁻¹ were sufficient, but spraying should begin as soon as symptoms appear and should be repeated at least once under severely deficient conditions.