Nutrients and the Nutrient cycle REVIEW QUESTIONSAnswer Key List 3 ways nitrogen is converted (fixed) from the atmosphere to a plant available form? Electrical fixation - lighteningSymbiotic fixation- RhizobiumNon- symbiotic fixation - Cyanobacteria ( Bluegreen Algae)Industrial Fixation - synthetic fertilizers How else is nitrogen added to the soil? ( besides from atmospheric nitrogen) Manures, dead plants and animals LIst 2 ways nitrate can be lost from the soil? Leaching Denitrification - turn to gas and release in the air How is ammonium lost from the soil? Volatilization - turns to gas and release in the air List 2 transformations in the soil that rely on bacteria and result in plant available nitrogen. Nitrification - conversion of ammonium to nitrate Mineralization - conversion of organics to minerals What happens to nitrate nitrogen under anaerobic conditions? Fixation Mineralization Ammonification Denitrification What is the plant available form of potassium? K+ KCl KNO3 K2CO3 Which nutrients would be most easily leached from the soil? Nitrate and sulfate Calcium and magnesium Ammonium and nitrate Calcium and sulfate Which of the following is classified as a micronutrient or trace element? Sulfur Calcium Iron Phosphorus What helps the plant obtain phosphorus from the soil? Mycorrhizae Rhizobium Calcium Nematodes How is phosphorus added to the soil? Organic matter Soil minerals Fertilizer All of the above What does phosphorus combine with in alkaline soils?a) sodium b) magnesium c) calcium d) iron What is the sign of nitrogen deficiency? Wilting New leave turn brown Old leaves turn chlorotic (yellow) Weak stems What is mineralization? Conversion of ammonium to nitrate Conversion of organic N to nitrate Conversion of ammonium to an organic compound Conversion of nitrate to atmospheric nitrogen What 3 elements come from air and water? nitrogen , oxygen, hydrogen Nitrogen, oxygen, carbon Carbon, hydrogen, oxygen Sulfur, hydrogen, carbon What 3 places is potassium found in the soil? Within the colloidsAttached to the colloidsIn solution In what plant family will you find rhizobium bacteria on the roots? Legumes - FABACEAE How is elemental sulfur converted to the plant available form? What is the plant available form? Through bacteria, SO4 -2