Growth Requirements of Plants

1. Growth Requirements of Plants By Emma, Zoe and Belinda

2. List each of the essential minerals and nutrients required for the plant to grow. For each explain how they assist plant growth +/- the symptoms of their deficiency. Non-mineral: • The three non-minerals are hydrogen(H), oxygen(O) and carbon(C) and they are found in the air and the water. They are part of photosynthesis because they are converted from • The Non-Mineral Nutrients are hydrogen (H), oxygen (O), & carbon (C). These nutrients are found in the air and water. • In a process called photosynthesis, plants use energy from the sun to change carbon dioxide (CO2 - carbon and oxygen) and water (H2O- hydrogen and oxygen) into starches and sugars. These starches and sugars are the plant's food. • Photosynthesis means "making things with light". • Since plants get carbon, hydrogen, and oxygen from the air and water, there is little farmers and gardeners can do to control how much of these nutrients a plant can use. • Most plants grow by absorbing nutrients from the soil. Depending on the location most soils contain a combination of sand, silt, clay and organic matter. Soil texture: • The texture of the soil effects how well nutrients and water are retained in the soil. Clays and organic soils hold nutrients and water much better than sandy soils. When water is drained from sandy soils it most likely carries nutrients with it. When this happens it is called leaching. When nutrients leach into soil the plants are not able to absorb nutrients. A good soil contains equal portions of sand, silt, clay and organic matter. Sometimes the nutrients that plants need occur naturally in the soil. Other times they need to be added to the fertiliser.

3. Mineral Nutrient • The 13 mineral nutrients, which come from the soil, are dissolved in water and absorbed through a plant's roots. There are not always enough of these nutrients in the soil for a plant to grow healthy. This is why many farmers and gardeners use fertilizers to add the nutrients to the soil. • The mineral nutrients are divided into two groups:

4. Macronutrients • Macronutrients can be broken into two more groups: Primary 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. Secondary nutrients. • The secondary nutrients are calcium (Ca), magnesium (Mg), and sulphur (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. Sulphur 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.

5. Macronutrients Nitrogen (N) • Nitrogen is a part of all living cells and is a necessary part of all proteins, enzymes and metabolic processes involved in the synthesis and transfer of energy. • Nitrogen is a part of chlorophyll, the green pigment of the plant that is responsible for photosynthesis. • Helps plants with rapid growth, increasing seed and fruit production and improving the quality of leaf and forage crops. • Nitrogen often comes from fertilizer application and from the air (legumes get their N from the atmosphere, water or rainfall contributes very little nitrogen) Phosphorus (P) • Like nitrogen, phosphorus (P) is an essential part of the process of photosynthesis. • Involved in the formation of all oils, sugars, starches, etc. • Helps with the transformation of solar energy into chemical energy; proper plant maturation; withstanding stress. • Effects rapid growth. • Encourages blooming and root growth. • Phosphorus often comes from fertilizer, bone meal, and superphosphate. Potassium (K) • Potassium is absorbed by plants in larger amounts than any other mineral element except nitrogen and, in some cases, calcium. • Helps in the building of protein, photosynthesis, fruit quality and reduction of diseases. • Potassium is supplied to plants by soil minerals, organic materials, and fertilizer

6. Calcium (Ca) • Calcium, an essential part of plant cell wall structure, provides for normal transport and retention of other elements as well as strength in the plant. It is also thought to counteract the effect of alkali salts and organic acids within a plant. • Sources of calcium are dolomitic lime, gypsum, and superphosphate. Magnesium (Mg) • Magnesium is part of the chlorophyll in all green plants and essential for photosynthesis. It also helps activate many plant enzymes needed for growth. • Soil minerals, organic material, fertilizers, and dolomitic limestone are sources of magnesium for plants. Sulphur (S) • Essential plant food for production of protein. • Promotes activity and development of enzymes and vitamins. • Helps in chlorophyll formation. • Improves root growth and seed production. • Helps with vigorous plant growth and resistance to cold. • Sulphur may be supplied to the soil from rainwater. It is also added in some fertilizers as an impurity, especially the lower grade fertilizers. The use of gypsum also increases soil sulphur levels.

7. Micronutrients Micronutrients are those elements essential for plant growth which are needed in only very small (micro) quantities . These elements are sometimes called minor elements or trace elements, but use of the term micronutrient is encouraged by the American Society of Agronomy and the Soil Science Society of America. The micronutrients are boron (B), copper (Cu), iron (Fe), chloride (Cl), manganese (Mn), molybdenum (Mo) and zinc (Zn). Recycling organic matter such as grass clippings and tree leaves is an excellent way of providing micronutrients (as well as macronutrients) to growing plants. Boron (B) • Helps in the use of nutrients and regulates other nutrients. • Aids production of sugar and carbohydrates. • Essential for seed and fruit development. • Sources of boron are organic matter and borax Copper (Cu) • Important for reproductive growth. • Aids in root metabolism and helps in the utilization of proteins. Chloride (Cl) • Aids plant metabolism. • Chloride is found in the soil. Iron (Fe) • Essential for formation of chlorophyll. • Sources of iron are the soil, iron sulphate, iron chelate. • Manganese (Mn)

8. Functions with enzyme systems involved in breakdown of carbohydrates, and nitrogen metabolism. • Soil is a source of manganese. • Molybdenum (Mo) helps in the use of nitrogen • Soil is a source of molybdenum. • Zinc (Zn) is Essential for the transformation of carbohydrates. It Regulates consumption of sugars. • Part of the enzyme systems which regulate plant growth. • Sources of zinc are soil, zinc oxide, zinc sulphate, zinc chelate.

9. List each of the environmental factors, explaining their affect. • If plants have too much sun they can start to dry out and they won’t have enough nutrients. • If there is too much water plants can start to drown because they cant take in all the water and • Temperature directly affects photosynthesis • Respiration transpiration - loss of water absorption of water and nutrients • Plant growth restricted by low and high levels of soil moisture can be regulated with drainage and irrigation good soil moisture improves nutrient uptake if moisture is a limiting factor fertilizer is not used efficiently. • Quality, intensity and duration of light are important Quality can't be controlled on a field scale - Feasible on specialty crops Intensity of light (brightness) is an important factor. Photosynthesis light intensity Composition of the atmosphere • Photosynthesis converts CO2 to organic material in the plant. CO2 is returned to atmosphere by respiration and decomposition • Increasing CO2 can increase crop yields respiration of plants and animals - decomposition of manure or plant residue may release CO2 Greenhouse crops • Plant growth and quality can be enhanced by supplemental CO2.

10. Are there plants that have ‘different’ nutritional needs, give examples. Carbon • The gas that forms the backbone of many plants’ biomolecules, including starches and cellulose is Carbon. From the carbon dioxide in the air, it is converted into photosynthesis and has a part in the carbohydrates that stores energy in the plant. Hydrogen • Another gas that is necessary for producing sugars and building the plant is Hydrogen which is almost entirely taken from just water. In photosynthesis and respiration, Hydrogen ions are absolutely necessary for a proton gradient to help steer the electron transport chain. Oxygen • Oxygen is imperative for cellular respiration, which is the process of generating a very rich adenosine triphosphate (ATP) by the consumption of sugars in photosynthesis. During photosynthesis, plants produce oxygen in order to produce glucose but then require oxygen for aerobic respiration to break down the glucose and convert it into ATP. Phosphorus • In plant bioenergetics, Phosphorus is a very important ingredient. During photosynthesis, Phosphorus is essential for the process of converting light energy to chemical energy (ATP). Through phosphorylation, Phosphorus can also be used for signalling cells and modifying the activity of various enzymes. Phosphorus is very important for the formation of flowers/seeds and the growth of plants because the biosynthesis of many plant biomolecules use ATP. Phospholipids, DNA and RNA are made up of Phosphate esters which, in soil, is mostly common in the form of polypro tic phosphoric acid (H3PO4), but is used when most ready in the form of H2PO4. Since phosphorus is released very slowly from phosphates that are insoluble, it is very limited in most soils and yet, it receives high demands from micro-organisms and plants. A sign of phosphorus deficiency can be an intense green colour in the leaves. If the plant is having high deficiencies in phosphorus, the leaves may become denatured and how symptoms of necrosis, the death of cells in a tissue. Potassium • Through a potassium ion pump, the opening and closing of the stomata is regulated by Potassium. Potassium helps the stomata to reduce water loss and increases drought tolerance. Potassium is useful as it can aid in the balance of anion charges inside the plant and also aid in photosynthesis by the formation of a chlorophyll precursor. It can, when in photosynthesis and respiration, serve as an activator of enzymes. Potassium is also used to build cellulose. Deficiency in Potassium can cause necrosis or intervene chlorosis and can result in wilting, chlorosis, brown spotting, a higher risk of pathogens and a higher chance of damage from frost and heat.

11. Carbon • The gas that forms the backbone of many plants’ biomolecules, including starches and cellulose is Carbon. From the carbon dioxide in the air, it is converted into photosynthesis and has a part in the carbohydrates that stores energy in the plant. Hydrogen • Another gas that is necessary for producing sugars and building the plant is Hydrogen which is almost entirely taken from just water. In photosynthesis and respiration, Hydrogen ions are absolutely necessary for a proton gradient to help steer the electron transport chain. Oxygen • Oxygen is imperative for cellular respiration, which is the process of generating a very rich adenosine triphosphate (ATP) by the consumption of sugars in photosynthesis. During photosynthesis, plants produce oxygen in order to produce glucose but then require oxygen for aerobic respiration to break down the glucose and convert it into ATP. Phosphorus • In plant bioenergetics, Phosphorus is a very important ingredient. During photosynthesis, Phosphorus is essential for the process of converting light energy to chemical energy (ATP). Through phosphorylation, Phosphorus can also be used for signalling cells and modifying the activity of various enzymes. Phosphorus is very important for the formation of flowers/seeds and the growth of plants because the biosynthesis of many plant biomolecules use ATP. Phospholipids, DNA and RNA are made up of Phosphate esters which, in soil, is mostly common in the form of polyprotic phosphoric acid (H3PO4), but is used when most ready in the form of H2PO4. Since phosphorus is released very slowly from phosphates that are insoluble, it is very limited in most soils and yet, it receives high demands from micro-organisms and plants. A sign of phosphorus deficiency can be an intense green colour in the leaves. If the plant is having high deficiencies in phosphorus, the leaves may become denatured and how symptoms of necrosis, the death of cells in a tissue. Potassium • Through a potassium ion pump, the opening and closing of the stomata is regulated by Potassium. Potassium helps the stomata to reduce water loss and increases drought tolerance. Potassium is useful as it can aid in the balance of anion charges inside the plant and also aid in photosynthesis by the formation of a chlorophyll precursor. It can, when in photosynthesis and respiration, serve as an activator of enzymes. Potassium is also used to build cellulose. Deficiency in Potassium can cause necrosis or interveinalchlorosis and can result in wilting, chlorosis, brown spotting, a higher risk of pathogens and a higher chance of damage from frost and heat.

12. Nitrogen • Nitrogen is an imperative part for all proteins. In many agricultural environments, nitrogen is a very limited nutrient for high growth. Some plants such as corn require more nitrogen than other plants. Deficiency of nitrogen often results in slow growth, stunted growth and chlorosis and plants will also display some purple on the stems, petioles and underside of the leaf because of an accumulation of anthocyanin pigments. When soluble forms of nitrogen are transported, they are transported as amines and amides. Sulphur • Sulphur is imperative in the production of chloroplasts and is an essential component of certain amino acids and vitamins. In photosynthesis, Sulphur can also be found in the Iron Sulphur complexes of the electron transport chains. It is motionless and therefore, sulphur deficiency will affect the younger tissues first. Yellowing of leaves and stunting of growth are some symptoms of sulphur deficiency. Calcium • Calcium helps transport other nutrients into the plant and is involved in activating some plant enzymes. If a plant has calcium deficiency, it will result in stunting, meaning it will not grow to its full potential. Magnesium • Magnesium plays a very important part in chlorophyll. There are many important biological roles for magnesium. One is in the production of ATP as an enzyme cofactor. If a plant has magnesium deficiency, it can result in interveinalchlorosis, which makes the plants’ leaves lose its green. Silicon • Silicon helps to strengthen cell walls, which improves plant strength, health and productivity in plants. Silicon also has many other benefits to plants, such as improved drought and frost resistance, decreased lodging potential and boosting the plant’s natural pest and disease fighting systems. Even though silicon is not considered as an imperative nutrient for plant growth and development (except for certain plant species), in many countries around the world, it is considered beneficial because of its many benefits to multiple plants species when under abiotic or biotic stresses. The second most bountiful element in the earth’s crust is silicon. Different plants have different characteristics and therefore need different amounts of silicon.