Chapter 37 - Plant nutrition. This chapter define soil texture and soil composition; explain why plants cannot extract all of the water in soil; define cation exchange and describe how plants can stimulate the process; discuss the problems of topsoil erosion and farm irrigation in arid regions; suggest actions that can help mitigate these problems. | CHAPTER 37 PLANT NUTRITION Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Section A: Nutritional Requirements of Plants 1. The chemical composition of plants provides clues to their nutritional requirements 2. Plants require nine macronutrients and at least eight micronutrients 3. The symptoms of a mineral deficiency depend on the function and mobility of the element Every organism is an open system connected to its environment by a continuous exchange of energy and materials. In the energy flow and chemical cycling that keep an ecosystem alive, plants and other photosynthetic autotrophs perform the key step of transforming inorganic compounds into organic ones. At the same time, a plant needs sunlight as its energy source for photosynthesis and raw materials, such as CO2 and inorganic ions, to synthesize organic molecules. The root and shoot systems extensively network a plant with its environment. Introduction Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Early ideas about plant nutrition were not entirely correct and included: Aristotle’s hypothesis that soil provided the substance for plant growth. Van Helmont’s conclusion from his experiments that plants grow mainly from water. Hale’s postulate that plants are nourished mostly by air. Plants do extract minerals from the soil. 1. The chemical composition of plants provides clues to their nutritional requirements Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Mineral nutrients are essential chemical elements absorbed from soil in the form of inorganic ions. For example, plants acquire nitrogen mainly in the form of nitrate ions (NO3-). However, as indicated by van Helmont’s data, mineral nutrients from the soil make only a small contribution to the overall mass of a plant. About 80 - 85% of a herbaceous plant is water. Because water contributes most of the hydrogen ions and some of the oxygen atoms that are incorporated into . | CHAPTER 37 PLANT NUTRITION Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Section A: Nutritional Requirements of Plants 1. The chemical composition of plants provides clues to their nutritional requirements 2. Plants require nine macronutrients and at least eight micronutrients 3. The symptoms of a mineral deficiency depend on the function and mobility of the element Every organism is an open system connected to its environment by a continuous exchange of energy and materials. In the energy flow and chemical cycling that keep an ecosystem alive, plants and other photosynthetic autotrophs perform the key step of transforming inorganic compounds into organic ones. At the same time, a plant needs sunlight as its energy source for photosynthesis and raw materials, such as CO2 and inorganic ions, to synthesize organic molecules. The root and shoot systems extensively network a plant with its environment. Introduction Copyright © 2002 Pearson Education, Inc., .
