Soil is a natural body of finely divided rocks, minerals, and organic matter. 沙子, 淤泥, 粘土, 有机物质有助于提供土壤, 必要的曝气和持水量, but seldom maintain adequately balanced nutrients (plant food) to sustain continuous plant growth and improved yield. Thus, requiring the addition of fertilizer to maintain their fertility.
I. 主要植物性食物元素
氮|磷|钾(钾肥) --- Plants utilize these nutrients in the largest amounts and unfertilized soils typically cannot provide them in quantities needed for optimal plant growth and yield.
氮(N) 1. 箴motes rapid vegetative growth (leaf and stems) hastening recovery after stress. 2. A vital element in the formation and function of chlorophyll, the key ingredient imparting dark green vegetative color. 3. 合成形成蛋白质的氨基酸. 4. 调节其他营养物质的吸收. 5. Basic ingredient of vital compounds – Nucleic acid and enzymes.
磷(P) 1. Stimulates early root formation and growth–gets plants off to a good start and form greater root biomass to better enable the soil area to collect the other nutrients 2. 加速成熟(淀粉转化为糖). 3. 刺激开花和种子发育. 4. Required for energy transformation and conversion processes in which 糖s are converted to hormones, 蛋白质和能量生长新的叶子和果实. 5. 形成核酸(DNA和RNA). 6. 对光合作用至关重要(植物绿化).
钾(K) 1. 有助于茎和叶的发育. 2. 增强抗病性和耐寒性. 3. 强化细胞壁. 4. 水 intake by plant cells can be affected; plants with inadequate potassium may wilt with more than enough moisture. 5. 作为铁吸收的催化剂. 6. 对蛋白质的形成和转运至关重要, 淀粉, 糖, 油可以改善水果的大小和质量, 谷物和块茎.
II. 次生植物食物元素
钙|镁|硫 They are used in less quantities than the primary elements, 但比微量营养素的量要大得多.
钙(Ca) 1. Calcium is an essential part of cell wall structure and must be present for the formation of new cells. 2. Deficiency of calcium causes weakened stems and premature shedding of blossoms and buds.
镁(毫克) 1. 对光合作用(植物绿化)至关重要. 2. Activator for many plant enzymes required in growth process.
硫(S) 1. A constituent of three amino acids and is therefore essential in the formation of protein. 2. 帮助植物保持绿色. 3. 改善碱性土壤. 4. Helps compacted soils–making them loose and allowing better water penetration. Sulfur Note –There are commonly two types of sulfur applied to plants and soils: Sulfate Sulfur ≠ (SO4); Elemental 硫(S).
3. 微量元素
铁|锌|锰 Even though micronutrients are used by plants in lesser amounts, they are just as essential for plant growth as primary and secondary nutrients. They must be maintained in balance for all nutrients and water to be used efficiently.
铁(Fe) Iron is required for the formation of chlorophyll in the plant cell (maintain a healthy green color). It serves as a catalyst for biological processes such as respiration, 氮与光合作用的共生固定. Applications of iron can correct iron deficiency, but it may be temporary in high pH soils.
锌(锌) 锌是几种植物酶的重要组成部分. It is a part of auxins and controls the synthesis of indoleacetic acid which regulates growth compounds. Zinc also affects the intake and efficient use of water by plants.
锰(Mn) 锰是植物中酶的活化剂. Without Manganese, the plants cannot use the iron which they have absorbed. It assists the iron in chlorophyll formation which causes yellowish plants to green up.
