Final Exam for Soil

What elements are excluded in the plant nutritional analysis?

C, H, O

What are C, H, and O required for?

For strucutral backbone of all organic materials

What do deficiency symptoms depend on?

Function of element and Mobility of element

What are some deficiency disorders

Complete crop failure, stunting, reduced root growth, specific leaf symptoms at different times, internal abnormalities, delayed/abnormal maturity, yield differences, and poor plant quality

What are some external influences that could cause toxicity disorders?

Disease, pests, injury, temperature, salinity, acidity, compaction, drought, or flooding

What are the five problem solving steps?

1. Locate abnormal plants

2. Visually assess plants to estimate problem

3. Send plant and soil samples for testing

4. Interpret results

5. Make recommendations

What are some nutrient application considerations, chemically?

Fertilizer quality, chemical interactions, residual fertilizer carryover, credits from subsoil, manure or residue, solid moisture, pH

What are some physical considerations for nutrient application?

State of application, application method, application timing, and incorporation

What are secondary effects?

They are a result of interdependent factors and appear once a nutrient is too high or too low

What is “Hidden Hunger”?

Crop needs nutrient but shows no deficiency symptoms/toxicity, yield may decline

TRUE OR FALSE: Nitrogen is very mobile

True

What are three symptoms of Nitrogen?

General chlorosis of lower leaves (starting at tip) and slow/stunted growth, high shoot growth with early flowering

TRUE OR FALSE: Phosphorus has a high reaction and is immobile

True

What are three symptoms of Phosphorus?

Purple/blue/red color in young plant leaves, stunted growth of root/leaves, and dark green and thick leaves

When does a plant most need phosphorus?

Seedling and germination stage

TRUE OR FALSE: Potassium is structural

False

What are three symptoms of Potassium?

Marginal necrosis and browning, white necrotic spots along leaflet margins, mottling

TRUE OR FALSE: Sulfur is immoble

True

What are two symptoms of Sulfur?

Whole plant is stunted and light colored, general chlorosis

TRUE OR FALSE: Calcium is immobile in plants?

True

What are two symptoms of Calcium and Magnesium?

Newer plant growth affected, poor root growth and deformed

TRUE OR FALSE: Magnesium is immobile?

False

Calcium causes ___ fever?

Milk

Magnesium causes _____?

Grass tetany

What micronutrient requires the most?

Iron

What is one symptom of Iron?

Interveinal yellowing of young leaves

What are three symptoms of Boron?

Newest cell walls improperly formed, plant stunting and discoloration, roots are stubby and bushy

What symptom is unique to Boron?

Roots stubby/bushy

What are three symptoms of Copper?

Yellowing of leaves moves from middle to tips, leaves are limp and fall off, dead cell patches

What is the main symptom of Zinc?

Striping on leaves, white/yellow

What are two symptoms of Manganese?

Grey speckling, extreme chlorosis

What is the main symptom of Molybdenum?

Wilting, twisting of new leaves (whip-tail)

TRUE OR FALSE: Chlorine is rarely deficient

True

Why does Chlorosis occur?

Mainly due to lack of chlorophyll production?

What nutrient causes purpling with chlorosis?

Phosphorus

What nutrient has reduced internode distance?

Zinc

What nutrient has generally smaller and darker plants?

Phosphorus

What nutrient has generally smaller and lighter plants?

Sulfur

What is the second most important factor to plant growth?

Nitrogen

How much percentage are plants N?

17%

What problems does Nitrogen cause?

Blue baby syndrome, groundwater contamination, eutrophication, acid rain, ozone depletion, climate change

What forms of Nitrogen cause blue baby syndrome?

Nitrite and Nitrate

What are the two most important functions of Nitrogen in soil?

Increase size and diversity of microbial population, N levels dictate rate of organic matter decomp

Where is Nitrogen found?

78% found in atmosphere

TRUE OR FALSE: Nitrogen is the most commonly lost nutrient?

True

What is nitrification?

It is when ammonia is converted to nitrites then nitrates

What is denitrification?

It is when Nitrates are converted to Nitrogen or other nitrogen gasses

What is immobilization?

When Nitrates and Ammonia are taken up by crops

What is mineralization?

When OM is converted to usable nutrients

How long does Nitrification take?

1-2 weeks

What are the two main factors that affect nitrification rate?

Nitrification organisms and NH4+ supply

How long does Denitrification take?

1-2 days

What are the two main factors that affect denitrification rates?

Denitrifying organisms, NO3- supply

What nutrient causes Immobilization of Nitrogen in plants?

Carbon

What are some sources of N?

Organic matter, N fertilizers, timing of application, nitrification inhibitors, urease inhibitors, manure/biosolid/compost, precipitation

What is the mineralization decay series?

A process over which 4 years N fertilizer is applied and calculated, 30% 20% 10% and 5%

What is the percent LTFE available?

52.5%

What are some considerations for N fertilizer requirements?

Yield/harvest, N demand, N credits, Soil properties, and economics

Define Soil

A dynamic natural body composed of mineral and organic materials, including living forms, which all support plant growth

How to find pH from a strong acid

pH= -log [H+]

How to find pOH from a strong base

pOH= -log [OH-]

How to find pH from pOH

pH= 14 - pOH

How to find Base Saturation

How to calculate Molarity

Moles of solute over Liters of solution

How to calculate moles

mass of solute (g) over molar mass (g/mol)

How to calculate lbs per acre furrow slice from transmittance

1. Convert transmittance to ppm in solution using standard curve

2. Convert ppm of solution to ppm in soil using DF, take DF times X of standard curve

3. Convert ppm to lbs/afs, multiple answer from step 2 by 2

How do anions move in the soil?

Mass flow

Sulfur is __ leached

Readily

Anions are __ soluble

Very

TRUE OR FALSE: S rxns are like N rxns

True

What are the three main sources of Sulfur in soil?

OM, fossil fuel combustion, and Fe/Al/S minerals

When soil is water logged what do micro-organisms use instead of O2 for energy?

SO4(-2)

Insufficient Sulfur can lead __ accumulation

Nitrogen

What percentage of plants have A in their protein structure?

90%

What nutrient is important for the folding of proteins?

Sulfur (Sulfur-Sulfur bonds)

Sulfur is often confused with which nutrient deficiency?

Nitrogen

Boron is important in..

Germination

Where does Boron come from?

Minerals

TRUE OR FALSE: Boron is important at both high and low conditions

True

Boron has similar characteristics to what nutrient(s)?

Calcium and Magnesium

How is chlorine mainly taken up?

Chloride anion

Chlorine is active in __ reactions

Energy

TRUE OR FALSE: Chlorine is structural

False

Chlorine addition aids in __ suppression

Disease

Where does Molybdenum come from?

Minerals

Molybdenum is needed for the uptake and transport of what nutrient in plants?

Iron

Molybdenum is more available what what phs?

High