What should guide fertilizer choices for a home garden?
A The fertilizer bag color
B Soil-test results
C A fixed yearly routine
D A neighbor’s lawn
Answer: B. Soil-test results. A soil test identifies current conditions and helps decide whether fertilizer is needed.
Which nutrients are represented by N-P-K on fertilizer labels?
A Nickel, phosphorus, calcium
B Nitrogen, potassium, calcium
C Nitrate, phosphate, calcium
D Nitrogen, phosphorus, potassium
Answer: D. Nitrogen, phosphorus, potassium. N-P-K lists nitrogen, phosphorus, and potassium in that order.
On an N-P-K label, what does the first number represent?
A Nitrogen percentage
B Phosphorus percentage
C Potassium percentage
D Organic matter percentage
Answer: A. Nitrogen percentage. The first number is the percentage of nitrogen in the product.
Which nutrient does the second N-P-K number represent?
A Nitrogen
B Potassium
C Phosphorus
D Calcium
Answer: C. Phosphorus. The second number represents phosphorus.
What does the third number on an N-P-K label represent?
A Nitrogen
B Phosphorus
C Potassium
D Sulfur
Answer: C. Potassium. The third number represents potassium.
When a fertilizer is labeled 10-10-10, what does that indicate?
A Equal N-P-K percentages
B No nutrients are present
C Ten pounds per plant
D Only nitrogen is included
Answer: A. Equal N-P-K percentages. The label lists equal percentages of nitrogen, phosphorus, and potassium.
For a 5-10-5 fertilizer, which nutrient has the largest listed percentage?
A Nitrogen
B Potassium
C Calcium
D Phosphorus
Answer: D. Phosphorus. The middle number is phosphorus, and 10 is the largest percentage in this formula.
Why are fertilizers sometimes called plant food inaccurately?
A Fertilizer contains no nutrients
B Plants make food through photosynthesis
C Roots cannot absorb minerals
D Leaves never need sunlight
Answer: B. Plants make food through photosynthesis. Plants make sugars through photosynthesis; fertilizer supplies mineral nutrients.
Which plant growth is nitrogen commonly linked with?
A Green leafy growth
B Soil drainage
C Seed coat thickness
D Flower color only
Answer: A. Green leafy growth. Nitrogen supports green vegetative growth.
Which plant functions are often associated with phosphorus?
A Leaf color alone
B Water drainage
C Stem thickness only
D Root and fruit development
Answer: D. Root and fruit development. Phosphorus supports root development and reproductive growth such as fruit and seeds.
How can potassium support plant growth?
A Creating sunlight
B Water movement and stems
C Replacing all nitrogen
D Preventing root growth
Answer: B. Water movement and stems. Potassium supports water and nutrient movement and contributes to strong stems.
What can a garden soil test report?
A Future rainfall totals
B Plant mature height
C Nutrients and soil pH
D Daily sunlight hours
Answer: C. Nutrients and soil pH. Soil testing can report nutrient levels and pH, among other soil properties.
Why test soil before buying fertilizer?
A Guarantee a larger harvest
B Remove every garden weed
C Change the soil texture
D Match nutrients to actual needs
Answer: D. Match nutrients to actual needs. Testing helps choose suitable nutrients and avoid unnecessary applications.
What can excess phosphorus eventually affect?
A Waterways and aquatic ecosystems
B Seed packet labels
C Garden tool storage
D Planting-row direction
Answer: A. Waterways and aquatic ecosystems. Excess phosphorus can move into waterways and contribute to water-quality problems.
What can too much nitrogen cause in a garden?
A Instant soil aeration
B Fewer plant roots always
C Excess leafy growth
D Permanent pest control
Answer: C. Excess leafy growth. Overapplication can cause excessive top growth and may increase disease or insect problems.
Why is one fertilizer formula not ideal for every garden?
A All plants absorb sunlight differently
B Soil and crop needs differ
C Bag sizes vary
D Every garden has identical soil
Answer: B. Soil and crop needs differ. Nutrient needs vary with the soil and the plants being grown.
How should gardeners use a soil-test recommendation?
A Ignore it after purchase
B Double every listed rate
C Apply fertilizer to paths
D Follow its nutrient guidance
Answer: D. Follow its nutrient guidance. Test recommendations help select suitable nutrient sources and rates.
What do the numbers on a fertilizer bag usually express?
A Nutrient percentages
B Number of plants covered
C Days until harvest
D Soil temperature ranges
Answer: A. Nutrient percentages. N-P-K numbers represent nutrient percentages in the product.
Do organic and synthetic sources supply nutrients plants can use?
A Only organic sources work
B Only synthetic sources work
C Yes, the nutrients are usable
D Neither supplies plant nutrients
Answer: C. Yes, the nutrients are usable. Plants absorb nutrient compounds; the source type does not change the nutrient element.
Why can compost or manure fertilizer rates be difficult to estimate?
A They contain no nutrients
B Nutrient content can vary
C Their labels are always identical
D They dissolve instantly
Answer: B. Nutrient content can vary. Nutrient concentrations can vary by source and material.
What can garden compost add to soil?
A Guaranteed pesticide protection
B Organic matter and nutrients
C A fixed N-P-K ratio
D Complete weed control
Answer: B. Organic matter and nutrients. Compost can add organic matter and nutrients, though its nutrient content varies.
What is an environmental risk of overusing fertilizer?
A More soil sunlight
B Lower water temperature
C Nutrients can reach waterways
D Fewer soil organisms always
Answer: C. Nutrients can reach waterways. Excess nutrients can move into waterways and harm water quality.
When is fertilizer most justified for a garden?
A When soil needs nutrients
B Whenever leaves are green
C On a fixed monthly schedule
D Before every rainfall
Answer: A. When soil needs nutrients. Use fertilizer when test results and plant needs show it is appropriate.
Why should fertilizer package directions be read?
A Labels replace soil testing
B All products use identical rates
C Labels show future weather
D Rates depend on the product
Answer: D. Rates depend on the product. Products differ in nutrient concentration and application directions.
How can concentrated fertilizer harm tender roots?
A Roots receive too much light
B It removes every soil particle
C Excess salts can injure them
D It increases root oxygen
Answer: C. Excess salts can injure them. Overapplication can create damaging salt concentrations near roots.
What should be measured before calculating fertilizer for a garden bed?
A The fence’s height
B The bed’s area
C The tool shed’s width
D The plant’s leaf color
Answer: B. The bed’s area. The amount needed depends partly on the area being treated.
How should granular fertilizer generally be distributed?
A In one heap per bed
B Only beside stems
C On nearby walkways
D Evenly as directed
Answer: D. Evenly as directed. Even application helps distribute nutrients, following the product and soil-test directions.
What should gardeners check before storing leftover fertilizer?
A Label and storage directions
B The next rain date
C The number of weeds
D The seedling color
Answer: A. Label and storage directions. Keep products in their labeled containers and follow package storage instructions.
Why keep fertilizer away from drains and waterways?
A Increase soil temperature
B Attract more earthworms
C Prevent nutrient runoff
D Protect garden labels
Answer: C. Prevent nutrient runoff. Keeping nutrients out of drains reduces runoff pollution.
What does slow-release fertilizer do?
A Stops all root growth
B Removes soil nutrients
C Works only in winter
D Releases nutrients over time
Answer: D. Releases nutrients over time. Slow-release formulations make nutrients available over a longer period.
Soil already has enough phosphorus but needs nitrogen; what is a sensible option?
A Add more phosphorus fertilizer
B Use a nitrogen-only source
C Apply extra compost blindly
D Avoid testing the soil
Answer: B. Use a nitrogen-only source. A nitrogen-only product can add needed nitrogen without adding unneeded phosphorus.
What can a high concentration of fertilizer salts do near roots?
A Draw water from root tissues
B Create extra root hairs
C Make soil less salty
D Replace irrigation
Answer: A. Draw water from root tissues. Excess soluble salts can make it harder for roots to take up water.
Why does soil pH matter when choosing nutrients?
A It determines rainfall
B It sets plant height exactly
C It replaces organic matter
D It affects nutrient availability
Answer: D. It affects nutrient availability. Soil pH can affect how readily plants access nutrients.
Which test can reveal whether soil pH needs adjustment?
A A rain gauge
B A leaf-count chart
C A laboratory soil test
D A fertilizer scoop
Answer: C. A laboratory soil test. A soil test can measure pH and provide recommendations.
How should samples from one similar garden area be collected?
A Mix several representative samples
B Use one surface pinch
C Collect only dry leaves
D Take soil from one pot
Answer: A. Mix several representative samples. Combining samples from several spots gives a more representative sample.
How should distinct garden areas be sampled if their soils differ?
A Mix all areas together
B Keep samples separate
C Test only the darkest soil
D Use a shared sample
Answer: B. Keep samples separate. Different areas can have different conditions, so separate samples give more useful results.
Why is a soil test more useful than guessing nutrient needs?
A It guarantees pest-free plants
B It replaces regular watering
C It measures existing soil conditions
D It predicts future harvests
Answer: C. It measures existing soil conditions. Testing helps identify current nutrient levels rather than relying on guesswork.
What should be considered before fertilizing ahead of heavy rain?
A Runoff risk
B The garden’s paint color
C The number of labels
D The size of seed packets
Answer: A. Runoff risk. Applying nutrients before heavy rain can increase runoff risk.
Which two organic materials can supply garden nutrients?
A Gravel and sand
B Plastic and glass
C Painted wood and ash
D Compost and manure
Answer: D. Compost and manure. Compost and manure can supply nutrients and organic matter.
How much fertilizer does every garden need?
A One fixed amount
B It depends on test results
C A full bag yearly
D More than plants use
Answer: B. It depends on test results. Some gardens need little or no additional fertilizer, depending on soil and crop needs.
What may happen when nutrients are applied beyond plant needs?
A Plants and waterways can suffer
B The soil becomes sterile instantly
C All weeds disappear
D Every crop grows faster
Answer: A. Plants and waterways can suffer. Excess fertilizer can harm plants and contribute to water pollution.
Which practice helps avoid unnecessary fertilizer use?
A Use the strongest formula
B Fertilize on every visit
C Test soil periodically
D Apply the same mix everywhere
Answer: C. Test soil periodically. Periodic soil tests can show when nutrients are needed and prevent overapplication.
Where should fertilizer N-P-K values be found?
A On a plant’s flower
B On the product label
C Inside the seed
D Under the garden bed
Answer: B. On the product label. Fertilizer labels disclose the nutrient analysis.
What is the standard order of the first three label numbers?
A Potassium, nitrogen, phosphorus
B Phosphorus, potassium, nitrogen
C Nitrogen, potassium, phosphorus
D Nitrogen, phosphorus, potassium
Answer: D. Nitrogen, phosphorus, potassium. The N-P-K order is nitrogen, phosphorus, and potassium.
What information helps calculate a suitable fertilizer amount?
A Test results and product analysis
B Flower color and pot shape
C Rainfall and fence height
D Seed age and garden tools
Answer: A. Test results and product analysis. The soil recommendation and product nutrient concentrations both matter.
When should fertilizer timing be chosen?
A By a fixed weekly rule
B Only during rain
C According to crop and product
D After every harvest
Answer: C. According to crop and product. Timing varies among crops and products; follow soil-test and label guidance.
Why is fertilizer not a substitute for healthy growing conditions?
A Fertilizer replaces sunlight
B Plants do not need air
C Soil becomes unnecessary
D Plants need light and water
Answer: D. Plants need light and water. Plants also need suitable light, water, air, and soil conditions.
Which information should decide whether phosphorus is added?
A The product’s bag color
B Soil-test recommendation
C Plant height alone
D The garden’s fence type
Answer: B. Soil-test recommendation. Soil test results indicate whether phosphorus is needed.
What is a careful fertilizer plan built around?
A Guess, add, and repeat
B Use every available nutrient
C Test, match, apply carefully
D Apply regardless of plant need
Answer: C. Test, match, apply carefully. Test the soil, match nutrients to needs, and follow application instructions.
Why should fertilizer be kept off leaves unless its label directs otherwise?
A It changes leaf color permanently
B It replaces the roots
C It prevents photosynthesis forever
D It may injure foliage
Answer: D. It may injure foliage. Some fertilizers can damage leaves; follow product directions for where and how to apply.