Chemistry of gardening

Ms. Knight Crystal Davidson 115 December 6 2013

Crystal DavidsonChemistry of gardening

The process by which plants produce their own food is called photosynthesis. In this process Carbon Dioxide and water along with light energy and chlorophyll are combined to make glucose. Chloroplast in plants traps light energy which is used to split water (H2O) into Hydrogen (H) and Oxygen (O) atoms. The hydrogen then combines with carbon dioxide (CO2) to make glucose (C6H12O6)

The equation for Photosynthesis is:6CO2+6H2OC6H12O6+6O2

Table showing the micronutrients their source, function and deficiencyMicronutrientsSource of nutrients Function the nutrientsResults of deficiency of nutrient

Boron Provided by Disodium Tetraborate (Borax)Essential for seed and call well formation. Important in the development and growth of new cells. It also helps in abruption of nitrogen. Boron is important in protein synthesis.Deficiency results in discoloration and rotting of roots. There is also a breakdown of internal tissues in root crops which results in darkened areas.

ZincProvided by Zinc SulphateInvolved in the formation or synthesis of chlorophyll. It is also responsible for plant growth. Zinc asserts protein and the production of Auxins A low zinc supply causes stunted plant growth and a deficiency in protein.

ManganeseProvided by Manganese (II) SulphateContributes to the production of chlorophyll. Supports movement of iron in plant

Deficiency leads to pour flavors in some crops

Copper Provided by Copper (II) SulphateNecessary for healthy growth of cereals It is also involved in the production of vitamin C and carotene. Loss of turger and develop a bluish green shade before becoming chlorotic and curling. The plant also fails to flower.

IronProvided by Iron (II) SulphateImportant component of the catalyst involved in chlorophyll formation.Deficiency leads to yellowing of leaves.

Table showing the macronutrients their sources, function and deficiencyMacronutrientsSource of nutrientFunction of the nutrientResults of deficiency of the nutrient

NitrogenIt is available through nitrogen fixation and from dead organisms and animal waste. It can also be available from organic manure and artificial fertilizers.Necessary for formation of amino acids -building block for protein. Essential for plant cell division, vital for plant growth.Necessary component of vitaminsA deficiently causes yellowing leaves and reduced branching.

PhosphorousPhosphorus often comes from fertilizer and bone meal superphosphate.Needed by with blubs, flowering plants and non-leafy vegetables. Involved in photosynthesis, respiration, energy storage and transfer, cell division, and enlargement.A deficiency causes leaves and stems to develop a purple coloration

Potassium Potassium is supplied to plant by soil minerals, organic materials and fertilizers.It is an enzyme activator its level determines the rate of reactions.A deficiency can cause stunted growth and permanent lost of leaves.

CalciumAvailable as free Ca2+ ions or in complex ions. Provided my calcium hydroxide calcium carbonate and calcium sulphate.Utilized for Continuous cell division and formation.Involved in nitrogen metabolismA deficiency leads to growth abnormalities.

MagnesiumAvailable as free Mg2+ ions or complex ionsHas an important role in chlorophyll formation.A deficiency leads to chlorosis-s a low chlorophyll content.

SulphurProvided by the pure element and ionic substances (SO42-)A constituent of some proteins enzymes and glycosides.Deficiency leads to stunted yellowish plants.

What are the components of good soil? The components of good soil are mineral matter which come from parent rock and organic matter which has humus which is a break down from animal and plant remains. It also has organic nutrients which are macro nutrients and micro nutrients. Water and air are the other ingredients in that makes up a good soil.Humus is formed from decomposition organic matter in soil is a dark semi-soluble organic substance. Humus enriches and improves the structure of the soil where plants grow and derive their nutrients. Humus is an important source of nutrient need for healthy plants to grow. It reduces the changes of small substances to be dissolved and flushed out of the lower layer of the soil by leaching. Increases the fertility of the soil buy providing a habitat for living organisms that changes soil nutrients to a form that plants are able to utilize. Soil nutrients are needed for normal growth of plants. There are two types of minerals non-mineral elements and mineral elements. The non mineral elements are obtained from the air and water, Carbon hydrogen and oxygen are then incorporated into the plants during photosynthesis.

1. Soil Type: SandySandy soil is made up large particles and has the largest particles among the different soil types. Its texture is dry and gritty. A disadvantage of sandy soil is that it cannot hold much water because of the huge spaces present between the particles. Whenever water enters sandy soil the water runs straight through where plant roots, particularly those of seedlings, cannot reach. Another disadvantage is that nutrients present in sandy soil are swiftly carried away buy runoff. An advantage of sandy soil is that it is light and easy to dig. Another advantage is that it warms up rapidly in the spring and seeds germinate very fast. The texture and fertility of sandy soil can be improved by adding rich organic matter.

2. Soil Type: SiltSilted soil has much smaller particles than sandy soil and its texture is smooth. Silted soil retains water longer. However a disadvantage is that it cannot hold many nutrients it is fairly fertile. However because of its moisture-retentive quality, silted soil is cold and drains poorly which is seen as an advantage.

3. Soil Type: ClayClay soil has the smallest particles among the different soil types so it has good water storage qualities. Its texture is sticky to the touch when wet, but smooth when dry. T here are many advantages of clay soil. Due to the tiny size of its particles and its tendency to settle together, little air passes through its spaces. Because its also slower to drain, it has a tighter hold on plant nutrients. Clay soil is thus rich in plant food for better growth. However, a disadvantage to Clay soil is that it is cold and in the spring, takes time to warm since the water within also has to warm up. Another disadvantage is that clay soil could be very heavy to work with when it gets dry.

4. Soil Type: Peaty Peat soil started forming over 9,000 years ago, with the rapid melting of glaciers. This rapid melt drowned plants quickly and died in the process. Their decay was so slow underwater that it led to the accumulation of organic area in a concentrated spot. An advantage of Peaty soil is its ability to hold water in during the dry months and its capacity to protect the roots from damage during very wet months. Another advantage of peaty soil is that it has a large percentage of organic matter which makes it a good growing medium. One disadvantage of peaty soil is that it is heavily saturated with water. Another disadvantage is that it contains acidic water

5. Soil Type: Saline SoilSaline soil has a high concentration of salt. The salinity is due to the buildup of soluble salts in the Rhizosphere. This type of soil is usually brackish in dry regions because of its high salt content. A disadvantage of Saline soil is that it can cause damage to and stall plant growth, impede germination, and cause difficulties in irrigation. It prevents water uptake by plants which leads to drought stress because of high salt content.

What is the purpose of the nitrogen cycle?The nitrogen cycle is essential to life as nitrogen is a vital component of every living organism. The cycle allows nitrogen to be reused by orgasms. Nitrogen atoms cannot be created there are only a certain amount found on Earth. Nitrogen gas is present in abundant in the air, 79% of the air is made up of nitrogen. It is extremely important component in molecules such as proteins and DNA. Plants absorb nitrogen from the soil as nitrate ions and use it to manufacture protein. The nitrogen is then combined with carbon, hydrogen and oxygen to make building blocks for DNA. How is nitrogen fixed in the soil?Nitrogen is fixed in the soil by nitrogen-fixing bacteria that converts nitrogen in the air to nitrates. The nitrogen gas is converted to nitrates because plants cannot absorb nitrogen gas they can only absorb substances with nitrogen present in it. Nitrogen fixing-bacteria make nitrogen available to plants in a form that they can utilize. The equation for converting nitrogen gas to nitrogen ions is: N2 + 8H+ e- NH3 + H2Nitrogen leaves the soil by a process called denitrification. Denitryfying bacteria convert nitrates in the soil back to nitrogen gas this activity reduce soil fertility since nitrogen is leaving the soil and plants uses it to grow well.The cycle maybe disrupted by leaching this occurs when water may passes through the soil on its way to river or streams and it carries dissolved nitrates and other nutrients along with it washing the nitrates out of the soil. Because Most of the nitrogen is used by the plant to produce protein (in the form of enzymes) a consequence of removal of nitrogen results in , a plant deficient in nitrogen will show yellowing in the older leaves due to the underdevelopment or destruction of chloroplasts.What is Acid soil?Acidic soil is soil that has a low pH range. Acidic materials react with base materials. Acidic materials increase the number of hydronium atoms. These acids donate protons to other chemicals surrounding them. When giving away protons, these acids fundamentally alter these chemicals, which can have beneficial or detrimental effects depending on the materials they're acting on. Soil acidity plays a large role in gardening

How is acidity removed from acid soil?Add a few drops of caustic to the soil, allow standing for at least two minutes, and rinsing with water. If the soil has been removed, an alkaline product can be recommended. If only a part of the soil was removed, further testing and treatment is necessary.Why should lime and an ammonium containing fertilizer not be used together?Adding fertilizers that contain both lime and ammonium has an undesired effect on the soil. Equal amounts of lime and ammonium may balance out, leaving the pH of the soil unchanged. A slightly unbalanced amount of lime or ammonium leads to a pH that is not acidic or alkaline enough, depending on the needs of the soil and the plants growing in the garden. Another problem associated with adding lime and ammonium fertilizers at the same time is fertilizer burn, which results from the application of excess fertilizers. Salts and other chemicals in fertilizer dry out the soil and the plants they are placed on, which gives grass, trees, shrubs and flowers a dried-out and burned appearance. Heavy and simultaneous applications of these two types of fertilizers do more harm than good to the garden. Lime will neutralize the function of ammonium fertilizer. Not letting Nitrogenavailable to the plant.

The equation is:(NH4)2SO4+Ca(OH)2 2NH3 + CaSO4 + 2H2O

What are fertilizers?A fertilizer substances that, if used correctly, improves crop yield by replacing lost nutrients Fertilizes may be classified into two ways:Inorganic fertilizers Organic fertilizersOrganic fertilizers come from natural sources such as manure, bone meal and composite while inorganic fertilizers are synthetic and are manufactured. Some inorganic fertilizers are ammonium sulphate and ammonium chloride. Some advantages of organic fertilizers is that nutrients are not easily leached or lost by run-off and therefore the there is less of a treat to water supply. While with inorganic fertilizers the nutrients can easily be leached into water supplies because the salts are soluble reducing the quality of water. Another advantage of organic fertilizers is that it has a beneficial binging effect on soil while inorganic fertilizer has no beneficial binding effect. Organic fertilizers do not need much attention once applied however it is the opposite with inorganic fertilizers because lime has to be added to salts which has been fertilized by ammonium compounds. One disadvantage of organic fertilizer is that nutrients are released slowly and this result in a slow up take by plant. An advantage of inorganic fertilizer is that it releases nutrients quickly which results in a quick up take by plants.

Organic fertilizers are cheaper that inorganic fertilizers in the long run. Because inorganic fertilizers contain soluble salts these salts can be dissolved by water from heavy rains and leached or carried into water systems such as lakes, streams and rivers which leads to death of many organisms living in it. This process is known as eutrophication. Organic fertilizers do not contribute to eutrophication because the nutrients from these fertilizers are not easily leached and less amount of nutrients are lost by run -off. Inorganic fertilizers do not improve soil stability and can lead to soil erosion. Inorganic fertilizers contribute to the green house effect. Nitrogen, phosphorus and potassium are the main ingredients of inorganic fertilizer. Nitrogen is an essential building block of plant, animal and human growth. When used in excess, nitrogen causes toxic overload in air and water supplies and changes natural ecosystems. Organic fertilizers are derived from natural sources and contain all 17 nutrients essential for creating life processes without harming air, water or humans. The pollution from fertilizing with chemical fertilizers causes algae blooms in surface water that can kill aquatic life. Excess nitrogen that enters the water supply for people can cause blue baby syndrome in infants when the concentration is more than 10 parts per million of nitrate nitrogen. Indiscriminate use of animal manures and human waste can create human health hazards through the accumulation of heavy metals and pathogens in the soil.

Some pests that can be found in a garden are insects, rodents, weed and other fungal plants. The various method of pest control include: chemical control biological, control and non-chemical control. With chemical control farmers practice pest management where they apply synthetic or naturally derived pesticides to help kill or get rid of pests that are consuming or destroying their crops. This method of pest control is used to get rid of insects, rodent and weeds and other fungal plants. Biological includes the usage living organisms like parasites, predators and pathogens to control insect pest, weeds or diseases. Organisms like vertebrates, invertebrates and fungi are used as biological control agents. These organisuims will feed on the pest that is harming the plants and remove of lessen them from the system.

Non chemical methods include:Plant SelectionUse disease and insect free, certified seeds and plants if available. Select plants that are sturdy and have well developed root systems. Diseases and insects in young seedlings may start in greenhouses or plant beds and cause heavy losses in the garden, i. e. whiteflies. Buy plants from a reputable grower who can assure you that they are disease and insect free. Avoid accepting plants from friends if there is any chance of also getting insects or diseases.

RotationPlanting two similar crops in successive years tends to increase pest problems. Many vegetables are closely related and have the same pests. Some insects hibernate or lay eggs in or on the host plant. Do not grow the same kind of vegetable in the same place each year. Use related crops in a site only once every 3 or 4 years. Another type of crop rotation is to not follow root crops behind other root crops. Crop rotation is most effective on insects that develop on a limited number of plants.

IntercroppingAvoid placing all plants of one kind together; alternate groups of different plants within rows or patches. Insects that become severe on cabbage will probably also infect nearby mustard, broccoli, and collards. If an insect lays eggs, or otherwise attacks a specific species, the presence of unrelated plants in the area can interrupt progress of the attack by diluting the attractive odor of the preferred plants. This can also slow the spread of diseases and pests, giving the gardener more time to deal with them. Marigolds and garlic are two plants whose merits are frequently advocated as insect repellants; however, most of these claims have not been proven. In some cases the evidence indicates they are not effective.

Herbicides!Herbicides are substances that destroy harmful plant such as weed.Selective herbicides controls specific chemical changes in the plantlike growth hormones while non-selective pesticides destroys all form of plant life an example of this herbicide is Paraquat it is fast acting and acutely toxic to humans.Hydroponics Is the practice of keeping plant roots in a solution that contains the nutrients required by plants this is the traditional water culture method while the sand culture is where gravel or sand or some other material is used as the rooting system and a nutrient solutions contains all the nutrients needed by the plant for its normal growth and development is aid. The disadvantage of hydroponics id that the range of plants that can be successfully cropped by this method is limited while soil supports a wide variety of plants. Support and anchorage problems must be catered for with the soil method anchorage and support are provided through the soil system. With the hydroponics there is a one way flow of system. The advantages of hydroponics are that it has no weed problems, and It allows for better control of the growing plants. It also requires a small labour force.