Fate of Zinc Ammonia Acetate in Soils and Its Uptake by Corn

ABSTRACT

Zinc ammonium acetate (ZAA) is applied to soil with anhydrous ammonia as a carrier to improve corn (Zea mays L.) productivity. To study the fate of ZAA in the soils, a laboratory leaching experiment was conducted with ¹⁴C-ZAA and ⁶⁵Zn-ZAA using water or NH₄OH as carrier. Results showed that ZAA degraded in the soil and released CO₂. The released CO₂ was from the acetate component of ZAA and accounted for less than 0.06% of the total applied ¹⁴C. Using H₂O as carrier resulted in more CO₂ release than using NH₄OH, regardless of soil type. However, more ¹⁴C was detected in the leachate when using NH₄OH as a carrier than when using H₂O. A plant uptake experiment using ¹⁴C-ZAA and ⁶⁵Zn-ZAA indicated that four-leaf-stage corn seedlings absorbed higher amounts of ¹⁴C in the stem and root than in the leaves. The ⁶⁵Zn was detected in most tested plant parts. Our study showed that ZAA enhanced cytokinin levels in root and/or shoot tissues of corn seedlings, suggesting a secondary regulatory effect of ZAA in improving corn productivity.

Keywords:

• ¹⁴C-ZAA
• ⁶⁵Zn-ZAA
• ammonium hydroxide
• leaching
• cytokinin

ACKNOWLEDGMENTS

This research was supported by Agri-Growth Research, Hollandale, MN.