Effect of Zinc On the Corn Yield On a Carbonate Chernozem (mollisol) Soil.

The goal of this project was to increase mineral fertilizer use efficiency and corn production. This study was conducted to determine whether application of zinc sulfate with nitrogen, phosphorus and potassium fertilizers would influence corn chlorosis, plant metabolism and productivity. The results of soil and plant analysis on nitrogen, phosphorus, potassium, and zinc indicated that their uptake by corn depended on fertilizers rates, corn chlorosis and zinc application. High levels of available phosphorus in the soil or systematic high application rates of phosphorus induced zinc deficiency in corn grown on carbonate chernozem (mollisol) soil. Zinc deficiency of corn affected the development of the leaves and was manifested as chlorosis beginning in the young leaves and progressing to the entire plant. Chlorosis was common in the interveinal areas of the leaves, which had yellow stripes and were yellowish in color. A soil phosphorus/zinc ratio of 95-104 indicated zinc deficiency in corn. The main symptoms of zinc deficiency were stunted growth, due to shortening of internodes, and decreased in leaf area. The application of zinc sulphate, nitrogen, phosphorus, and potassium reduced zinc deficiencies and increased corn growth. Zinc sulphate at 5-10 kg·ha^-1 increased leaf area, plant height, chlorophyll content, and plant biomass; yield of corn was increased from 470 to 660 kg·ha^-1. Application of zinc with macronutrients reduced concentrations of nitrates, and inorganic phosphorus; increased organic phosphorus, and protein from 161 to 217 kg·ha^-1. Zinc application is suggested to increase phosphorus use efficiency, corn productivity and quality.
*The results were obtained in Moldavian Scientific-Research Institute of Soil Science and Agricultural Chemistry, Chisinau, MD, Moldova.