zinc sulfate 250 gm
home gardening product
Zinc (Zn) is an essential micronutrient for plant life. In Minnesota, while some soils are capable of supplying adequate amounts for crop production, addition of zinc fertilizers is needed for others. Zinc is a recommended micronutrient in fertilizer programs for production of corn, sweet corn, and edible beans. Several research projects have focused on the use of this nutrient, and much of the following information is based on the results of that research.
Natural sources of zinc
Zinc exits naturally in rocks. The amount of zinc present in the soil depends on the parent materials of that soil. Sandy and highly leached acid soils generally have low plant available zinc. Mineral soils with low soil organic matter also exhibit zinc deficiency. In contrast, soils originating from igneous rocks are higher in zinc. Plants take up zinc as the divalent ionic form (Zn2+) and chelated-zinc.
The role of zinc in the plant
Zinc is an important component of various enzymes that are responsible for driving many metabolic reactions in all crops. Growth and development would stop if specific enzymes were not present in plant tissue. Carbohydrate, protein, and chlorophyll formation is significantly reduced in zinc-deficient plants. Therefore, a constant and continuous supply of zinc is needed for optimum growth and maximum yield.
Research at the University of Minnesota as well as other universities has identified soil conditions where a response to zinc fertilizers is expected. These conditions are:
Soil Temperature: Cool soil temperatures in early spring can intensify the need for zinc. When soil temperature is low, mineralization of soil organic matter slows down resulting less amount of zinc being released in the soil solution. Root growth is also stunted by cool temperatures and reduces the plant’s ability to find new sources of zinc in the soil profile.
Soil Texture: In Minnesota, crop response to fertilizer-zinc takes place mostly on fine-textured soils. Recent studies indicate a response to zinc can occur when high yielding crops are grown on sandy soils with low organic matter content. However, the measured response to zinc fertilization in these situations has been small and has not occurred every year. Soil tests for zinc are recommended to determine if zinc is needed in a fertilizer program.
Topsoil Removal: The probability of a response to zinc fertilization increases where topsoil has been removed or eroded away. When soils are eroded, the amount of free calcium carbonate on the soil surface increases. The need for zinc in a fertilizer program increases as the percentage of free calcium carbonate increases.
Previous Crop: The probability of a response to zinc fertilization increases if either corn or dry edible beans follows a crop of sugar beets (a non-mycorrhizal plant). This condition is termed as “fallow syndrome” and is a result of poor colonization of the plant root with arbuscular mycorrhizal fungus which increases the plant’s ability to take up phosphorus and zinc.
Phosphorus Level: There is a known relationship between phosphorus and zinc in the soil. Previous studies in Minnesota have shown excessive application of phosphate fertilizers caused zinc deficiency in corn, which resulted in reduced grain yield. This yield reduction occurred mainly in calcareous soil with high pH (pH > 8.3) and low soil test phosphorus and zinc. A phosphorus-induced zinc deficiency is a concern and may occur only if very high rates of phosphate fertilizer (more than 200 lb P2O5/acre) are used and the soil test for zinc is in the range between Low and Very Low.