* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Soils - Nmsu
Survey
Document related concepts
Arbuscular mycorrhiza wikipedia , lookup
Human impact on the nitrogen cycle wikipedia , lookup
Soil erosion wikipedia , lookup
Soil respiration wikipedia , lookup
Crop rotation wikipedia , lookup
Plant nutrition wikipedia , lookup
Terra preta wikipedia , lookup
Soil horizon wikipedia , lookup
Surface runoff wikipedia , lookup
Soil compaction (agriculture) wikipedia , lookup
Soil food web wikipedia , lookup
No-till farming wikipedia , lookup
Canadian system of soil classification wikipedia , lookup
Soil salinity control wikipedia , lookup
Soil microbiology wikipedia , lookup
Transcript
Review Symplastic transport Apoplastic transport In which of the following are transport proteins are involved? 1. 2. 3. 4. Facilitated diffusion Osmosis Active transport 1&3 In which of the following are transport proteins are involved? 1. 2. 3. 4. Facilitated diffusion Osmosis Active transport 1&3 Which one of the following requires ATP: 1. 2. 3. 4. Facilitated diffusion Osmosis Active transport 1&3 Which one of the following requires ATP: 1. 2. 3. 4. Facilitated diffusion Osmosis Active transport 1&3 Where is ABA produced? Where is ABA produced? Roots Where is ABA produced? Roots ABA signals the stomata to open. True False Where is ABA produced? Roots ABA signals the stomata to open. True False Soils Soil • How is it made? • What are some of the physical characteristics of soil? • What are some of the chemical characteristics of soil? • Are there different types of soil? – What are they? Soil Weathering of rocks Wind Rain Ice Acid secretion from plant roots Soil Physics • Soil Texture: – Soil is classified by size: – Sand 0.02 to 2mm – Silt 0.002 to 0.02mm – Clay less than 0.002mm Soil Properties Particle Size vs Area Soil Triangle Phys • Bulk Density: – Weight per unit volume of any soil • rocks = 2.5 g/cm2 • Soil = 1.5 g/cm2 • Air and water availability Soil Structure Solid part arrangement Platy Prismatic Columnar Blocky Granular Soil Horizon A horizon: Smallest soil particles Sand, silt and clay Depth Humus Decaying organic material Organisms Soil Horizon B horizon: Larger particles Less weathered sand and rocks Less organic material Depth Soil Horizon C horizon: Rocky Aquifers Bedrock Chemical Properties Cation Exchange Capacity (CEC) ability of soil to hold positively charged ions e.g. ammonium (NH4+), calcium Ca++, sodium (Na+) Function of Texture and Organic Matter finer texture and O.M. increase CEC Soils have little ability to hold negatively charged ions (e.g. nitrate (NO3-)) Chemical Properties Soil pH Measure of acidity (hydrogen ions - H+) Range = 0 – 14 Based on acidity of pure water Disassociation of water molecule H20 ↔ H+ + OH10 -7 g H+ and oh- / liter water -log of 10-7 pH = 7 Chemical Properties pH Substance Soils 2 Vinegar - 4 Orange juice Forest 6 Milk Agricultural soils 7 Pure water Agricultural soils 8 Sea water NM soils 9 Soap Arid pH vs Plant Nutrients Cu, Zn Manganese Phosphorus Boron Iron 4.0 5.0 6.0 7.0 8.0 9.0 10.0 Chemical Properties Benefits of Organic Matter Increases CEC (fertility) of soil Increases water holding capacity Provides nutrients for plants Reduces root diseases How? Increases the pop. of beneficial microorganisms to out compete the disease organisms. Water Holding Capacity Water Holding Capacity (WHC): amount a water held by a soil; a function of texture. Field Capacity (FC): amount of water held against the force of gravity after irrigation. Permanent Wilting Point (PWP): amount a water at which the plant wilts permanently. (Does not hold well for desert plants) Available Water (AW): FC - PWP = AW Conclusions • Soil texture and depth determine : – WHC for water storage and CEC for nutrient status. – Crop productivity is linked directly to texture and depth. • Productivity can be decreased by: – increased salts – increased bulk density Review Physical Characteristics of Soil Chemical Characteristics of Soil