- Why "20 Domains" Really Means Three Outlines
- The Full Domain Map at a Glance
- General Agriculture Outline: Domains 1-7
- Drip/Micro Outline: Domains 8-16
- Sprinkler Outline: Domains 17-20
- Choosing a Specialty by Weighting
- Format, Calculators, and Test-Day Mechanics
- Fees, Eligibility, and Renewal Mechanics
- Sequencing Your Study by Domain
- Where the Credential Gets Used
- Frequently Asked Questions
- The "20 domains" are three separate outlines: General Agriculture (1-7), Drip/Micro (8-16), and Sprinkler (17-20). You sit General plus one specialty.
- General Agriculture is 150 questions; Sprinkler adds 50 (200 total), Drip/Micro adds 75 (225 total). Each exam allows four hours.
- Sprinkler Type alone carries 40%-50% of the Sprinkler exam, making it the single heaviest domain across all outlines.
- Hydraulics appears in all three outlines at 15%-25% weights, so fluency there pays off on both exams you take.
Why "20 Domains" Really Means Three Outlines
The Certified Irrigation Designer - Agriculture pathway, administered by the Irrigation Association (IA), is easy to misread. When you see "20 content areas," it is natural to imagine one giant blueprint and one giant exam. That is not how it works. The 20 entries come from three separate official outlines, and you will only ever be tested on two of them.
- Entries 1-7: the General Agriculture outline, which every candidate takes.
- Entries 8-16: the Drip/Micro outline, one of two specialty options.
- Entries 17-20: the Sprinkler outline, the other specialty option.
You take General Agriculture plus one specialty. Choose Sprinkler and you face 150 + 50 = 200 questions. Choose Drip/Micro and you face 150 + 75 = 225 questions. Each exam allows four hours, so the combined allowance is eight hours spread across two sittings. Both exams must be passed within three years of application.
If you are new to the credential itself, our overview at What Is CID-AG? covers the basics before you dive into the blueprint below.
The Full Domain Map at a Glance
The table below lists every domain exactly as the outlines present them, with the official percentage ranges. Note that several domain names repeat (Hydraulics, Pumps, Scheduling) because each outline covers them from its own angle, with different weights.
| # | Domain | Outline | Weight |
|---|---|---|---|
| 1 | Pumps | General Agriculture | 15%-20% |
| 2 | Hydraulics | General Agriculture | 20%-25% |
| 3 | Economics | General Agriculture | 5%-10% |
| 4 | Soil-Water-Plant Relations | General Agriculture | 15%-20% |
| 5 | Scheduling | General Agriculture | 10%-15% |
| 6 | Efficiency/Uniformity | General Agriculture | 10%-15% |
| 7 | System Components | General Agriculture | 10%-15% |
| 8 | System Design/Economics | Drip/Micro | 20%-25% |
| 9 | Hydraulics | Drip/Micro | 15%-20% |
| 10 | Filtration | Drip/Micro | 15%-20% |
| 11 | Emitting Devices | Drip/Micro | 5%-10% |
| 12 | Injection | Drip/Micro | 5%-10% |
| 13 | Soil-Water-Plant Relations | Drip/Micro | 5%-10% |
| 14 | Scheduling | Drip/Micro | 5%-10% |
| 15 | Efficiency/Uniformity | Drip/Micro | 10%-15% |
| 16 | Pumps | Drip/Micro | 1%-5% |
| 17 | Pumps and Power | Sprinkler | 15%-20% |
| 18 | Hydraulics | Sprinkler | 20%-25% |
| 19 | Scheduling | Sprinkler | 10%-15% |
| 20 | Sprinkler Type | Sprinkler | 40%-50% |
Because these are official ranges rather than fixed percentages, the exact mix on any given form can shift. Treat the ranges as a guide to where your preparation time belongs, not as a promise of precise question counts.
General Agriculture Outline: Domains 1-7
This is the exam everyone takes, and at 150 questions it is the larger of the two. It tests the foundation that sits underneath any agricultural irrigation design, regardless of whether the final system is sprinkler or drip.
Hydraulics (20%-25%) and Pumps (15%-20%)
Together these two domains account for roughly 35% to 45% of the General exam. Hydraulics is the single most heavily weighted domain in this outline, and pumps is not far behind. Expect calculation-driven questions: friction loss through pipe, velocity limits, elevation effects on pressure, and sizing a pump to meet a required flow at a required pressure.
Hydraulics: What You Must Be Able to Do
Work from a described field layout to a defensible pressure and flow answer, without relying on memory of a finished design.
- Calculate friction loss in mainlines and laterals and recognize which pipe-material assumptions apply.
- Account for elevation change when determining pressure at the farthest point in the system.
- Evaluate whether a given pipe size keeps velocity within a sensible range.
- Combine system curve and pump curve logic to find an operating point.
Pumps: Selection and Operation
Questions here test whether you can match equipment to a hydraulic requirement rather than recite definitions.
- Read and interpret pump performance curves.
- Understand how changes in flow or head shift the operating point.
- Recognize the practical limits that affect pump suction and installation.
Soil-Water-Plant Relations (15%-20%)
This domain connects the engineering to the agronomy. You need to understand how soil texture and structure govern water holding and infiltration, how plants extract water from the root zone, and how those factors set the demand a system must satisfy. It also underpins the scheduling domain, so the two should be studied together.
Scheduling, Efficiency/Uniformity, System Components, and Economics
Scheduling (10%-15%) asks when and how much to irrigate based on crop water use and soil storage. Efficiency/Uniformity (10%-15%) tests how well water is distributed and how much is productively used. System Components (10%-15%) covers the physical building blocks of a design. Economics (5%-10%) is the lightest General domain but still shows up in questions about comparing cost alternatives.
Drip/Micro Outline: Domains 8-16
The Drip/Micro specialty is the nine-domain outline, with 75 questions. It is more fragmented than the Sprinkler outline, spreading weight across many mid-sized topics instead of concentrating it in one.
System Design/Economics (20%-25%)
The heaviest Drip/Micro domain. It asks you to lay out a system for a given crop and field: choosing emitter spacing and flow rates, sizing laterals and submains, dividing the field into blocks, and weighing cost against performance. Because design and economics are bundled, expect questions that make you justify a choice rather than simply compute a number.
Hydraulics (15%-20%) and Filtration (15%-20%)
Drip emitters operate at low pressure with tiny passages, so the hydraulic tolerance is tight. You need to understand how pressure variation along a lateral translates into flow variation at emitters. Filtration is equally important in practice: clogging is the main failure mode of micro-irrigation, so questions probe matching filter type and mesh to the water source and the emitter.
Filtration: Matching Filter to Water Quality
This is a distinctly Drip/Micro topic that has no counterpart in the Sprinkler outline.
- Know which filter styles suit which contaminants (sand, organic matter, suspended solids).
- Understand pressure loss across filters and why it matters to the overall hydraulic design.
- Recognize how flushing and maintenance affect long-term performance.
The Smaller Drip/Micro Domains
- Efficiency/Uniformity (10%-15%): measuring and improving how evenly emitters deliver water.
- Emitting Devices (5%-10%): types of emitters and how their flow responds to pressure.
- Injection (5%-10%): introducing fertilizer or chemicals through the system and protecting the water source.
- Soil-Water-Plant Relations (5%-10%) and Scheduling (5%-10%): the drip-specific application of concepts from the General exam, such as wetted-volume considerations and frequent small applications.
- Pumps (1%-5%): a minimal slice, since the heavy pump content lives in the General exam.
Sprinkler Outline: Domains 17-20
The Sprinkler specialty has just four domains and 50 questions, but the weighting is lopsided in a way that rewards focused preparation.
Sprinkler Type (40%-50%)
This is the largest single domain anywhere on the credential. Nearly half of the Sprinkler exam concerns the types of sprinkler systems and how they behave.
- Know the characteristics, strengths, and limitations of the different agricultural sprinkler systems.
- Understand which system suits which field shape, crop, soil intake rate, and wind exposure.
- Be ready to evaluate application rate against soil infiltration to avoid runoff.
The other three domains are Hydraulics (20%-25%), Pumps and Power (15%-20%), and Scheduling (10%-15%). The hydraulics here is applied to sprinkler laterals and mainlines, and Pumps and Power extends the pump content into energy and driver considerations, which ties directly to operating cost.
Choosing a Specialty by Weighting
Many candidates pick a specialty based on their field experience, which is sensible. But the structure of each outline also changes how you should prepare, so it is worth comparing them side by side.
| Factor | Sprinkler | Drip/Micro |
|---|---|---|
| Specialty questions | 50 | 75 |
| Combined total with General | 200 | 225 |
| Number of domains | 4 | 9 |
| Largest domain | Sprinkler Type (40%-50%) | System Design/Economics (20%-25%) |
| Breadth of topics | Narrow, concentrated | Broad, spread out |
| Allowance per exam | 4 hours | 4 hours |
The Sprinkler outline rewards depth: master one huge domain and you have secured close to half the specialty exam. The Drip/Micro outline rewards breadth: no single topic dominates, so gaps in filtration, injection, or emitter behavior each cost you. Neither is automatically easier. For a broader look at relative difficulty, see How Hard Is the CID-AG Exam?
Key Takeaway
Decide your specialty first, then build a plan that front-loads the shared foundations (hydraulics, pumps, scheduling, soil-water-plant relations). Those topics appear in the General exam and again in your specialty, so they earn points twice.
Format, Calculators, and Test-Day Mechanics
Every question is multiple choice. The exams are closed book, but provided formula material and scratch paper are available during the test. Because so many domains are calculation-heavy, calculator rules matter.
- Permitted calculators are silent, battery-powered, and nonprinting. Programmable models are allowed.
- Phone, tablet, and watch calculators are not allowed.
- Breaks do not stop the clock, so manage your time accordingly.
- Testing takes place at Kryterion testing centers, with select IA paper-and-pencil administrations. At-home proctoring has not been verified, so do not plan around it.
The passing standard is form-dependent and usually falls between 70% and 75%, rather than a single fixed cutoff. We break down what that means in practice at CID-AG Passing Score, and the available data is discussed in CID-AG Pass Rate.
Fees, Eligibility, and Renewal Mechanics
Because this is a two-exam pathway, costs are calculated per exam. Initial fees are $250 per exam for IA members and $495 per exam for nonmembers, which works out to a two-exam total of $500 for members or $990 for nonmembers. Retakes cost $200 (member) or $325 (nonmember) per exam, so a failed attempt on one exam does not require repaying for the other.
Experience and education are recommended rather than mandatory. The handbook suggests three years in the field, or two years in the field plus one related educational year. No required prep course, degree, or reference count has been identified. A full walkthrough lives at CID-AG Requirements, and a complete fee breakdown is at CID-AG Certification Cost.
Once certified, annual renewal is $75 for members and $125 for nonmembers, plus $25 for each additional certification. Maintaining the credential requires 20 CEUs per two years, including at least 10 irrigation-related CEUs and 5 Tier 1 (water-efficient) CEUs.
Sequencing Your Study by Domain
Rather than a generic schedule, order your preparation around how the domains depend on one another. This sequence assumes a Sprinkler or Drip/Micro specialty after General Agriculture.
Hydraulics and Pumps
- Drill friction loss, elevation, and velocity calculations until they are routine.
- Practice reading pump curves and finding operating points.
- These feed domains 1, 2, 9, 16, 17, and 18.
Soil-Water-Plant Relations and Scheduling
- Link soil water storage to crop demand and irrigation timing.
- Cover domains 4 and 5 first, then the specialty versions.
Efficiency, Components, and Economics
- Finish the remaining General domains (3, 6, 7).
- Sit a full-length practice run of the 150-question format.
Your Specialty Outline
- Sprinkler: concentrate on Sprinkler Type, then Hydraulics and Pumps and Power.
- Drip/Micro: start with System Design/Economics, then Filtration and Hydraulics.
For a broader method and exam-day approach, see the CID-AG Study Guide, and keep the CID-AG Cheat Sheet nearby for last-minute review. When you are ready to test your recall under realistic conditions, use the CID-AG practice tests to find which domains still need work.
Where the Credential Gets Used
The Certified Irrigation Designer credential with an agriculture track signals competence in designing irrigation for farms and large-scale production. People who pursue it typically work in irrigation design and consulting, equipment dealerships and distribution, engineering services, and agricultural operations that manage their own systems. The agriculture focus, with its emphasis on pumping, field hydraulics, and crop water demand, distinguishes it from credentials aimed at landscape or turf irrigation.
If you are weighing whether the investment pays off, see Is the CID-AG Certification Worth It?, and for earnings context see the CID-AG Salary Guide. To explore roles, visit CID-AG Jobs.
Frequently Asked Questions
No. The 20 domains come from three separate outlines. You take the General Agriculture exam (domains 1-7) plus one specialty: Drip/Micro (domains 8-16) or Sprinkler (domains 17-20). You only need to prepare for the outlines that apply to your two exams.
Sprinkler Type, at 40%-50% of the Sprinkler exam, is the largest single domain. Within the other outlines, General Hydraulics (20%-25%) and Drip/Micro System Design/Economics (20%-25%) lead. Hydraulics is a major weight in every outline.
The General Agriculture exam has 150 questions. A Sprinkler specialty adds 50 for a total of 200, and a Drip/Micro specialty adds 75 for a total of 225. Each exam allows four hours, and all questions are multiple choice.
The standard is form-dependent and usually falls between 70% and 75%, rather than being a fixed universal cutoff. Because it varies by form, aim to be comfortably strong in every domain rather than targeting the minimum.
Silent, battery-powered, nonprinting calculators are permitted, including programmable models. Phone, tablet, and watch calculators are not allowed. Formula material and scratch paper are provided, and breaks do not stop the clock.