Mineral deficiencies are frequently suspected when livestock performance does not meet the farmers expectations, particularly when animal growth rates do not meet target weights, livestock have a low resistance to parasites, production levels (wool or milk) are poor or reproductive performance of mature animals is poor.
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Plant Nutrition
Macronutrients Macronutrients can be broken into two more groups: primary and secondary nutrients. The primary nutrients are Nitrogen (N), Phosphorus (P), and Potassium (K). These major nutrients usually are lacking from the soil first because plants use large amounts for their growth and survival. The secondary nutrients are Calcium (Ca), Magnesium (Mg), and Sulfur (S). There are usually enough of these nutrients in the soil so fertilization is not always needed. Also, large amounts of Calcium and Magnesium are added when lime is applied to acidic soils. Sulfur is usually found in sufficient amounts from the slow decomposition of soil organic matter, an important reason for not throwing out grass clippings and leaves.
Soil Characteristics
pH The pH of the soil very largely governs the availability of its nutrients. pH exerts an important influence on soil structure, and determines the activity or inactivity of various micro-organisms. In acidic soils low concentration levels of potassium, magnesium, copper, zinc and cobalt generally occur. Lignosulphonates are derived from Lignin and are a by-product of the pulp and paper industry, meaning they are organic in nature. In trees and higher plants lignin acts as a cementing agent to bind the matrix of cellulose fibers together into a rigid woody structure.
An important property of the metal chelates is their stability constant. This number is specific for each metal and chelate molecule and defines the relative stability of the metal chelate in terms of the ratio of bound metal in the chelate to free metal ion not bound in the chelate structure. This is why synthetic chelating agents form stronger bonds with some trace elements than others.
Common Visual Symptoms
While it can be hard to ascertain the exact nutrient deficiency when multiple symptoms are present, if your crop begins to exhibit signs of nutrient deficiencies it is a good idea to have plant tissue analysis undertaken for a definite result. What is foliar fertilization?
Foliar fertilization is feeding the plant nutrients through its leaves. Foliar fertilization has gained increasing importance as a means of supplying essential nutrients, especially trace elements. Foliar application if iron, zinc, copper and manganese are often used on crops in preference to soil application, because soil uptake is poor due to the fact that these elements generally are not available from the soil. (Refer to Newsletter 102 and 103). Their availability from the soil is affected by such factors as soil pH, moisture content, organic matter, microorganisms and other elements present in the soil. Obviously, foliar application avoids these soil factors resulting in greater availability of these minerals to the plants. If applied properly, foliar application is frequently the most practical way to supply trace elements. During the middle of the nineteenth century, Leibig discovered the law of the Minimum.
If several nutrient elements are present in the soil in amounts that would be insufficient for maximum plant yield, the yield will be determined solely by the supply of the element that is present in the smallest amount relative to the plant requirement, increasing the supply of other elements has no effect on yield.
After a Long Drought
Waterlogging occurs when rainfall or irrigation water collects on the soil surface for prolonged periods without infiltrating the soil. Soil characteristics that contribute to waterlogging include soil physical properties that allow formation of a crust on the soil surface or of a pan in the subsoil. Waterlogging can also occur when the amount of water added through rainfall or irrigation is more than what can percolate into the soil within one or two days.
Many common algae’s are controlled easily with algaecides, but resistant algae are those that are extremely difficult to control because they have protective mucilage which are completely covering the chloroplast, that resists penetration from chemicals.
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