SWES 210 1st Edition Lecture 12Outline of Last Lecture II. agriculturea. historyIII. what is soila. differences between soil (color, size, porosity, other)b. soil profilec. plant growth (horizons)d. idea topsoilIV. soil and agriculturea. unhealthy soil signsb. what causes unhealthy soilc. soil erosiond. dust storms (dust bowl)e. conserving soil (governmental policy)Outline of Current Lecture V. World food productions since 1960a. Norman Borlaug and the green revolutionb. MonocultureVI. Nutrients and fertilizersa. Essential plant nutrients b. Mineral nutrients (macro and micronutrients)c. Photosynthesisi. Necessity for N and P (limiting for primary productivity)d. Iron also a limiting plant nutriente. Algae blooms (affecting coastal and open ocean waters)f. Fertilizer (N and P) from Midwestern farms affecting water quality in gulfVII. Dead Zones globallyCurrent Lecture- World food productions since 1960o Global production of most foods have risen more quickly that world population over the past half century largely because of the Green Revolution (increase yields without increasing the amount of land needed)o Borlaug: Rust and disease resistant weeds, shuttle breedingo 2 growing seasonso selectively bred wheat to incorporate resistance traits form different linesThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.o selectively bred wheat to decrease stem height- the semi dwarf varietieso monoculture= large expanses of a single cropo human diet narrowed: 90% of our food comes from 15 crop and 8 livestock species- nutrients and fertilizerso essential plant nutrients, 16 elements known to be essential for plant growth (carbon, hydrogen oxygeno mineral nutrients macronutrients= nitrogen, phosphorus, potassium, calcium, magnesium, sulfur micronutrients: boron, copper, iron, chlorine, manganese, molybdenum, zinco photosynthesis= primary productivity CO2 + H2O+ solar energy= C6H12O6 (sugar)+O2 In order to build this, you need N to have proteins, and you need P in order for ATP to happen in order to build other moleculeso Nitrogen is the most important limiting factor for primary productivity in coastal ocean waterso Iron is an effective limiting nutrient for open ocean waters (iron has low solubility in sea water with a pH of 8)o Haida salmon restoration corporation (HSRC)- 2012 iron fertilization off british Columbiao Algae blooms Nitrogen input phytoplankton flourish at the surface Dead phytoplankton and their waste drift to the bottom, providing more food for bacteria to decompose Microbial decomposer population grows and consumes more O2 Insufficient oxygen suffocates fish and shrimp at the bottom dead zone (hypoxic zone) formso Fertilizer (nitrogen and phosphorus) from Midwestern farms, livestock manure, sewage treatment plants, street runoff, industrial and vehicle emissions,add nutrients to mississippi river, which causes Phytoplankton to grow in gulf of mexico, then.. Bacteria to eat dead phytoplankton and wastes, Growth of bacteria depletes oxygen causing hypoxia Fish and other aquatic organisms suffocate leading to a “dead zone”- Dead zones world wideo Over 400 dead zones occur globally Mostly off coasts of Europe and US Mostly due to farm, city, and industrial pollution Some are seasonal, others permanento Fisheries and ecosystems are impacted (over $2 billion/year in lost