Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download ES Unit 5 Part 2 Sustainable Agriculture
Document related concepts
no text concepts found
Transcript
Create a T chart Titled: Overpopulation and fill it in Problems Solutions Intro to Part 2 We have been discussing how the human population has grown exponentially over the past 250 years. The growth rate is decreasing (which is good) but we are still using our land resources at a rate faster than we should be. Can you think of any solutions to this problem? Sustainable Agriculture: Hydroponics Design Experiment Learning Goals Students will be able to Describe the basic anatomy and physiology of plants Explain ways in which we can create more sustainable agriculture. Design an experiment to test what grow medium works best with our NFT hydroponics system. Today… Plant Anatomy Cells Tissues Organs Plant Physiology Water & sugar transport Notes What is plant anatomy? ANATOMY: study of the structure of organisms… looking at cells, tissues (Morphology: Study of form) What is plant physiology? • PHYSIOLOGY: study of the function of cells, tissues, organs of living things; and the physics/chemistry of these functions… Always keep in mind that in plant (and animal) anatomy, morphology & physiology… “Structure correlates to function” How can water move from the ground all the way to the top of a 100 m tall redwood tree? Notes Plant Anatomy: Cells Plant cells are basic building blocks Can specialize in form and function By working together, forming tissues, they can support each other and survive Levels of organization atoms > molecules > cells > tissues > organs > whole plant > pop. Notes Plant Tissues Types All plant organs (roots, stems, leaves) are composed of the same tissue types. There are three types of tissue: 1. Dermal – outermost layer 2. Vascular – conducting tissue, transport 3. Ground – bulk of inner layers Notes 1. Dermal tissue Epidermis is the outermost layer of cells Like the “skin” of animals In stems and leaves, epidermis has cuticle, a waxy layer that prevents water loss. Some have trichomes, hairs. Root epidermis has root hairs, for water and nutrient absorption Notes 2. Vascular tissue Transports water and organic materials (sugars) throughout the plant Xylem – transports water and dissolved ions from the root to the stem and leaves. • Phloem – carries dissolved sugars (carbohydrates) from leaves to rest of the plant Xylem Transports water and dissolved minerals Tracheids: long, thin tube like structures without perforations at the ends Vessel elements: short, wide tubes perforated at the ends (together form a pipe, called vessel). Both cells have pits (thin sections) on the walls Tracheids Vessel elements Phloem Cells that transport organic materials (sugars) Phloem cells are ALIVE! (unlike xylem) However, they lack nucleus and organelles Notes 3. Ground tissue Makes up the bulk of plant organs. Functions: Metabolism, storage and support. Root Stem Leaf Plant Organs Organs: tissues that act together to serve a specific function Leaves Dermal Vascular Ground Stems Dermal Vascular Ground Roots Dermal Vascular Ground Check for Understanding 1. What is the basic unit of life in a plant? 2. What are the three types of tissues in plants? 3. What are the three organs in a plant? Check for Understanding 1. What is the basic unit of life in a plant? Cell 2. What are the three types of tissues in plants? Dermal, Vascular, and Ground 3. What are the three organs in a plant? Roots, stem, leaves Notes Functions of plant organs: ROOTS: Anchorage, water/nutrient absorption from soil, storage, water/nutrient transport STEMS: Support, water/nutrient transport LEAVES: Photosynthesis (food production) ROOTS ROOTS “the hidden half” Functions of roots: Anchorage Absorption of water & dissolved minerals Storage (surplus sugars, starch) Conduction water/nutrients STEMS Above-ground organs (usually) Support leaves and fruits Conduct water and sugars throughout plant (xylem and phloem) Stem Vascular tissue Vascular bundles – composed of both xylem and phloem Xylem Conducts water Support Phloem Conducts Support food Vascular cambium LEAVES: Photosynthetic “factories” of the plant… Function: Photosynthesis – food production for the whole plant Blade: Flat expanded area Petiole: stalk that connects leaf blade to stem, and transports materials BLADE Leaf epidermis Is transparent – so that sun light can go through. Waxy cuticle protects against drying out Lower epidermis: stomata with guard cells – for gas exchange (CO2, H2O in; O2 out) Water transport in plants: The same way we drink soda from a straw! Water’s great cohesive forces (molecules sticking to each other) and adhesive forces (attaching to walls of xylem cells) Transpiration-cohesion Theory for water transport in the xylem Evaporation of water in the leaves (through stomates) generates the ‘sucking force’ that pulls adjacent water molecules up the leaf surface. What is this process called? (from water cycle lesson) Water transport (cont.) Like a long chain, water molecules pull each other up the column. The column goes from roots leaves. What’s amazing is that the water moves up by using the sun’s evaporative energy… Plants control transpiration by opening/closing stomata Check for Understanding 1. What type of vascular tissue in the stem transports water up from the roots to the leaves? 2. What type of vascular tissue in the stem transports sugars (carbohydrates) and nutrients down from the leaves to the stem and roots? 3. What is the name of the process where evaporative forces or adhesion and cohesion help pull water up from the roots to the leaves? Check for Understanding 1. What type of vascular tissue in the stem transports water up from the roots to the leaves? Xylem 2. What type of vascular tissue in the stem transports sugars (carbohydrates) and nutrients down from the leaves to the stem and roots? Phloem 3. What is the name of the process where evaporative forces or adhesion and cohesion help pull water up from the roots to the leaves? Transpiration Sustainable Agriculture Hydroponics is the process of growing plants without the use of soil. It is considered a type of sustainable agriculture. What does sustainable agriculture mean? Opening Assignment 1. What is sustainable agriculture? 2. List the function of the following parts of a plant A. Xylem: B. Phloem: C. Roots: D. Leaves: Sustainable agriculture is . . . . Sustainable agriculture takes many forms, but at its core is a rejection of the industrial approach to food production developed during the 20th century. This system, with its reliance on monoculture, mechanization, chemical pesticides and fertilizers, biotechnology, and government subsidies, has made food abundant and affordable. However, the ecological and social price has been steep: erosion; depleted and contaminated soil and water resources; loss of biodiversity; deforestation; labor abuses; and the decline of the family farm. The concept of sustainable agriculture embraces a wide range of techniques, including organic, free-range, low-input, holistic, and biodynamic. Sustainable agriculture is . . . . The common thread among these methods is an embrace of farming practices that mimic natural ecological processes. Farmers minimize tilling and water use; encourage healthy soil by planting fields with different crops year after year and integrating croplands with livestock grazing; and avoid pesticide use by nurturing the presence of organisms that control cropdestroying pests. Beyond growing food, the philosophy of sustainability also espouses broader principles that support the just treatment of farm workers and food pricing that provides the farmer with a livable income. Critics of sustainable agriculture claim, among other things, that its methods result in lower crop yields and higher land use. They add that a wholesale commitment to its practices will mean inevitable food shortages for a world population expected to exceed 8 billion by the year 2030. There's recent evidence, though, suggesting that over time, sustainably farmed lands can be as productive as conventional industrial farms. Questions to be answered today using my website Login to my website and go under “My Blog” Answer the following questions using complete sentences Let’s Review what you learned about Plants using Kahoot! Go to Kahoot.it on your phone Hydroponics Introduction 1. What are 3 scenarios in which hydroponics would be a great solution? 2. If hydroponics does not use soil then where does the root get it’s nutrients from? Germination Germination – is the process where a plant grows from a seed. What do plants need to grow from seeds? Plants need . . . Water Seeds need water to loosen up the outer layer of the seed so it can break open. Also the seed needs to absorb the water so cellular metabolism can take place. When the seeds are formed, the plant stores nutrients and starches inside the seed so when the seed needs to germinate, the plant will use up these nutrients first. These are all the nutrients that the seed needs to begin life and shortly after sprouting, the plant will need to find another source of nutrients other than just its shell. Water activates all these changes and will begin the process of life. Plants need . . . Oxygen Seeds need oxygen also to start the process of germination. The seeds will use up oxygen for aerobic respiration until the plant grows it leaves and can absorb CO2 naturally. This is a main source of energy needed by your seeds. If you submerge the seeds and they can not get any oxygen, you can prevent the seeds from germinating. Plants need . . . The right temperature Temperature affects cellular metabolic and growth rates. Seeds from different species and even seeds from the same plant germinate over a wide range of temperatures. Seeds often have a temperature range within which they will germinate, and they will not do so above or below this range. Many seeds germinate at temperatures slightly above 60-75 F (16-24 C) [room-temperature if you live in a centrally heated house], while others germinate just above freezing and others germinate only in response to alternations in temperature between warm and cool. Most seeds like to germinate in the 75-90 degree temperatures. Plants need . . . . Light . Most seeds are not affected by light Light can be an environmental trigger for germination and is a type of physiological dormancyor darkness, but many seeds, including species found in forest settings, will not germinate until an opening in the canopy allows sufficient light for growth of the seedling. The seeds I have chosen all can be started in sunlight but there are seeds that require darkness to germinate. So how do we put all this together and germinate seeds for hydroponics? We will use a seed starting dome which will help us control the humidity and temperature to start the seeds. Step 1: Start by filling up the bottom tray with enough water to come up inside the growing chambers in your dome just a little. Maybe only a centimeter or so. The seeds have enough nutrients in the seed shells to get started and don’t need us to add anything to the water just yet. Step 2: Take your starting cubes or rockwool and rinse it off with water to make sure you get out all the small particles from production. This will also give everything a good safe PH of 7.0. Place these starting cubes down inside the dome and deep enough in the chambers to touch the water. This will allow the cube to wick up the water and stay moist, but not drown the seed at the same time. Step 3: I like to then place 2 seeds in each staring cube and hope that at least one of them germinates. If you want to use more starting cubes and spots in your germination dome, then you can do one seed in each. If both seeds start growing, I clip the smaller one-off and leave the larger one growing. After it sprouts . . . . . Small amounts of nutrients are okay to add to the water after you get the plants to grow a little. Remember that these plants are still very small and fragile so adding too much of anything in their food supply can burn them up. I usually give them a couple of weeks to get established then I add only a small serving of nutrients to the water. I will add about 1/8 to 1/4 of the recommended dosage of nutrients. If you start to see the tips of the leaves burn up, back off your nutrients and add more pure water to the mix for a while. Starting our seeds https://www.youtube.com/watch?v=J1kt8qwuRTw Nutrient Film Technique NFT System https://www.youtube.com/watch?v=p4mOFtiotj8 Opening Assignment Get your Chapter 13 questions and your notes on plant anatomy and physiology out. These resources are also on my website. I will be giving you the study guide for the Unit 5 Test today to work on in class. While you are working on this, I will call you over to the “Germination Station” to get your plant started.
