Certified Crop Adviser (CCA) with Sustainability Specialty · USA / Canada / international · International Certified Crop Adviser program (American Society of Agronomy)
Original practice questions written to the published syllabus · not past papersFeeding crops while keeping nitrogen and phosphorus out of air and water: nutrient budgets, use-efficiency metrics, the 4R framework, integrated nutrient management and the planetary-boundary view of nitrogen and phosphorus.
In the exams: ICAR AIEEA-PG Physical Science Unit IV; ICAR AICE Soil Science; CCA exam and 4R Nutrient Management Specialist
How our questions for Certified Crop Adviser with Sustainability Specialty spread across the units of Nutrient Stewardship & Nitrogen Management. Difficulty: 4 easy, 15 medium, 1 hard.
| The 4R framework: right source, rate, time, place | 3 | |
| Site-specific and sensor-based nitrogen management | 3 | |
| Nutrient management plans and regulation | 3 | |
| Nutrient use efficiency metrics: partial factor productivity, agronomic efficiency, recovery efficiency | 2 | |
| Farm and field nutrient budgets | 2 | |
| Integrated nutrient management with organic and biological sources | 2 | |
| Enhanced-efficiency fertilisers | 2 | |
| Phosphorus legacy and peak-phosphorus debates | 2 | |
| Nutrient recovery from wastes | 1 |
Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.
A 100 ha dairy farm's inputs are 10,000 kg N fertiliser, 8,000 kg N in purchased feed, 2,000 kg N fixation and 1,000 kg N deposition; it sells 4,000 kg N in milk and 1,000 kg N in animals. What is its farm-gate N surplus per hectare?
D. 160 kg N/ha
Inputs 21,000 - outputs 5,000 = 16,000 kg; / 100 ha = 160. The first wrong figure is the farm total, not per ha; 80 omits feed N, the largest blind spot; 210 ignores outputs.
A field shows a persistent phosphorus surplus for 20 years. Where does most of the surplus P go?
D. Into soil P stores, building legacy P that raises future runoff risk
P accumulates in soil (legacy P); losses then occur with erosion and runoff, especially from P-saturated soils. Phosphine and nitrate are wrong.
Which of these is an example of the 'right time' in 4R nutrient stewardship?
B. Splitting nitrogen so most is applied during rapid crop uptake
Splitting matches timing to uptake. The others illustrate source, place and rate.
Why is only part of the nitrogen in cattle manure available to a crop in the year of application?
A. Much of it is organic N that mineralises slowly over months and years
The ammonium fraction is quickly available (and volatile); the organic fraction becomes available over time, hence availability coefficients in plans.
A green manure crop is estimated to supply 120 kg N/ha, of which 50% is available to the next crop. If the next crop needs 150 kg N/ha from fertiliser and green manure combined, how much fertiliser N is needed?
A. 90 kg N/ha
Available credit = 120 x 0.5 = 60; fertiliser = 150 - 60 = 90. Crediting all 120 kg overstates supply; ignoring the credit wastes N; adding is wrong.
A canopy sensor reads NDVI 0.72 in a field and 0.80 in a well-fertilised N-rich strip. What is the sufficiency index?
D. 90%
SI = field/reference = 0.72/0.8 = 90%. Inverting gives 111%; the difference x 100 is 8; 72 ignores the reference.
What is the main purpose of yield monitors and multi-year yield maps in nutrient management?
A. Identifying stable high- and low-yielding zones for variable-rate application
Yield maps help define management zones and realistic yield goals; they do not measure soil nutrients or rain.
Under which conditions is a urease inhibitor most likely to pay?
B. Surface-applied urea on warm, moist, high-pH or residue-covered soil with no rain soon after
Volatilisation risk is highest for surface urea in warm, moist, alkaline or residue-rich conditions without incorporation or rain.
Which soil phosphorus test is generally recommended for neutral and alkaline soils?
A. Olsen sodium bicarbonate test
Olsen suits neutral and calcareous soils; Bray and Mehlich-3 suit acid soils; Walkley-Black measures organic carbon and Kjeldahl total N.
A field drains 200 mm of water in a winter at an average of 15 mg/L nitrate-N. How much N is leached per hectare?
C. 30 kg N/ha
1 mm of water on 1 ha = 10,000 L, so 200 mm = 2,000,000 L; x 15 mg/L = 30,000,000 mg = 30 kg N. 3,000 forgets units; 3.0 slips a factor of 10; 133 is nitrate, not nitrate-N.
Ten here, 20 in the app. The Laisha app has every practice question we have written to Certified Crop Adviser with Sustainability Specialty in this subject, marked as you go, with timed papers, a jump-to-unanswered list and a certificate when you pass at 70 per cent.
Free for ten days, then one subscription of US$10 a month. We would rather say so here than have you find it later.
An AI operating system for agriculture: free guides, manuals and tools written for every country.