Also known as a minor element fertilizer, contains plant nutrients calcium, magnesium and sulphur in one or more of the compounds, and the need to indicate the content type of fertilizer. Minor constants is mainly nitrogen, phosphorus and potassium compared to the scale of production and application. China called elements in fertilizers. In addition to providing crop nutrients this fertilizer, and soil physical properties can be adjusted to promote agricultural production. Elements in fertilizer production for a long time, not attention. Reasons are commonly used in fertilizers, especially at low concentrations in fertilizers containing calcium, magnesium or sulfur, sulfur dioxide in the atmosphere by rain into the soil, is one of the sources of sulfur. For more than 30 years, fertilizer structure high concentration fertilizers and gradually replaced the low concentrations in fertilizers, make into calcium, magnesium, and sulfur in the soil decreased the shortfall nutrients in some soils, especially the shortage of sulfur, so that elements in fertilizer production and use to get attention. Fertilizer containing calcium and magnesium limestone, dolomite powder, lime, crushed shells, and other industrial waste containing calcium, magnesium, and is widely used as a soil conditioner and provide calcium and magnesium nutrients. Its soil is follows: improving the availability of soil phosphorus fertilizer in. High soil containing iron, aluminum oxide, due to phosphate reacts with compounds of iron, aluminium, phosphate fertilizer effectiveness diminishes. Applying conditioner keeps the soil pH in calcium and magnesium 6~7, can slow the reaction above. II soil ammonium into nitrate in response to most of the nitrifying bacteria need calcium. Promote the process of biological nitrogen fixation. ④ Adjust crop uptake of trace elements, maintain soil pH at 6~7Shi, micronutrients for crops to maintain a certain degree of effectiveness. II improvement of soil physical properties, mainly improving the soil particle size distribution. Common calcium magnesium phosphate (phosphate) also have this effect.
Sulfur-containing fertilizers are mainly used for adjusting the soil alkaline and salt (the soil contains too much sodium chloride and carbonate). Large amounts of calcium sulphate (gypsum) used to improve saline-alkali land or submerged soil, with good results. India succeeded in using pyrite improving alkaline soil and calcareous soil. For some higher magnesium deficiency soil pH, not applying dolomite powder, is to apply anhydrous potassium magnesium sulfate or magnesium sulfate, magnesium silicate serpentine powder can also be used. In recent years, have developed a new technique, molten Elemental sulfur coated urea particle surface, provide sulfur to the soil on the one hand, on the other hand make urea n fertilizers to improve nitrogen use efficiency.
Silicon-containing fertilizers for soil conditioners, soil improvement, attenuated also, pest and disease prevention and the role of, for its nontoxic, odorless, does not deteriorate, erosion, pollution-free and other advantages, will be the development of ecological agriculture in high quality fertilizer. Silicon fertilizer applied to reduce phosphorus fixation in the soil, activation fix phosphorus in soils, and to promote the transfer of phosphorus in plants, thereby increasing utilization.