Total Nutrient Uptake: The amount of a given mineral nutrient acquired during the growing season. ![]() When developing fertilizer recommendations, two major aspects of plant nutrition are important to understand and manage high yield corn production: A re-evaluation of nutrient uptake and partitioning can provide the foundation for fine-tuning our practices as we strive to achieve corn’s maximum yield potential. Current fertilization practices developed decades ago, may not match the requirements of newer hybrids which are now grown at population densities higher than ever before. Table 3 list the six mobile and eight immobile mineral nutrients. Sulfur is one element that lies between mobile and immobile elements depending on the degree of deficiency.ĭeveloping Fertilizer Recommendations, understanding Nutrient Uptake and Partitioningīiotechnology, breeding, and agronomic advancements have increased corn yields to new highs. Conversely, if only the upper leaves show the deficiency, then the plant is likely deficient with an immobile nutrient because that nutrient cannot move from older to newer leaves. Knowing which nutrients are ‘mobile’ is very useful in diagnosing plant nutrient deficiencies because if only the lower leaves are affected, then a mobile nutrient is most likely the cause. Some nutrients can also move from older tissue to newer tissue if there is a deficiency of that nutrient. How nutrients move within the plantĪll nutrients move relatively easily from the root to the growing portions of the plant. The secondary macronutrients (Ca, Mg, S) often do not depend of diffusion because their solution concentrations are fairly high in soil, relative to plant requirements. The nutrients that are most dependent diffusion to move them toward a plant root are relatively immobile, have relatively low solution concentrations, and yet are needed in large amounts by the plant, such as P and K. Fertilizing near the plant root, the plant is less dependent on exchange processes and diffusion to uptake nutrients, especially P. It has been found that ‘ diffusion’ accounts for the remainder of the nutrient movement.ĭiffusion is the process where chemicals move from an area of high concentration to any area of low concentration. Specifically, mass flow has been found to account for about 80% of N movement into the root system of a plant, yet only 5% of the more immobile P. This process is referred to as ‘ mass flow’, accounts for a substantial amount of nutrient movement toward the plant root, especially for the mobile nutrients such as NO 3. Water moves toward and into the root as the plant use water or transpires. Therefore, other mechanisms must cause the movement of nutrients to the plant. Roots come directly in contact with some nutrients ( interception) as they grow however, this only accounts for a very low percentage of the total amount of nutrients taken up by plants. Nutrient uptake by roots is dependent on the activity of the root (corn root number, root dry matter, and root length), ability to absorb nutrients, and the nutrient concentration at the surface of the root. Additionally, understanding how nutrients function within the plant is useful in diagnosing nutrient deficiencies. Knowing what form of a nutrient the plant absorbs helps inform what controls the cycling and movement of the nutrient in the soil. ![]() Most fertilizers are made up of combinations of these available nutrient forms, so when fertilizer dissolves, the nutrient(s) can be immediately available for uptake. How plants uptake nutrients:Įach of the nutrients cannot be taken up by plants in its elemental form, they must instead be taken up in an ‘ionic’ or charged form, with the exception of boron (B) as boric acid which is uncharged (Table 2). 025% or 250ppm, of dry plant tissue (Table1). ![]() Most of the macronutrients represent 0.1 -5% or 100-5000 parts per million (ppm), of dry plant tissue, whereas the micronutrients generally comprise less than. ![]() The micronutrients include boron (B), chlorine (Cl), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), nickel (Ni), and zinc (Zn). The macronutrients, N, P, K, are often classified as primary macronutrients, because deficiencies of N, P, K are more common than the secondary macronutrients, Ca, Mg, and S. There are 6 macronutrients: nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S). The 14 mineral nutrients are classified as either macronutrients or micronutrients based upon plant requirements and relative fertilization need.
0 Comments
Leave a Reply. |