Grade 10: Planning and Evaluating a Crop Investigation
Teacher-use draft for the intended Grade 10 audience. Select for the stated prerequisites; exact current programme, subject name, strand and term placement remain editorial checks. This is an original teaching activity, not an official assessment or approved syllabus allocation.
A crop investigation begins with a question and a recording rule, not a hoped-for result. This activity compares two sowing-depth treatments in a deliberately small fictional container study. It supplies the plan, a usable blank sheet, a completed record and a cautious evaluation. The objective is to plan and interpret an investigation, not to recommend a planting depth for any real crop.
All dates, crop codes and observations are simulated. The complete paper route needs no plants. An optional real version must first be redesigned and directly supervised by the responsible teacher for an identified suitable seed, materials, site and learners. The invented 10 mm and 20 mm treatment depths below are not universal crop instructions. If the teacher cannot confirm their suitability, use the paper record or different approved conditions.
The completed investigation plan
Question: In this model, how many seeds in each depth treatment produce a visible shoot above the growing-medium surface by day 14? Prediction: The groups may differ; write a reasoned prediction before viewing the results, then retain it even if the results disagree. “The deeper seeds will all fail” is an unsupported certainty.
| Design element | Stated plan |
|---|---|
| Intended difference | A1–A3: 10 mm sowing depth; B1–B3: 20 mm |
| Comparison unit | One container with one seed; three containers per treatment |
| Comparable conditions | Same identified seed batch, container size, growing-medium batch and amount, observation time and teacher-set care protocol |
| Position allocation | Use a random draw to assign the six labelled containers to six prepared positions; record positions and any later move |
| Response | For each seed, record whether a shoot has ever been seen above the surface by each visit |
| Visits | Day 0, day 7 and day 14, at 09:00 in the model; record any missed visit |
| Endpoint | Count containers with observed emergence by day 14; keep the individual records |
The teacher prepares and checks the safe materials and oversees sowing, care and disposal. Use no pesticides, fertiliser dosing, manure, sharp tools or tasting in this activity. Do not handle unidentified plants or fungi. The teacher arranges handwashing, safe access and suitable alternatives; stop and use the records if conditions are unsuitable. Any care departure must be logged rather than hidden to preserve a preferred conclusion.
Equal care should be defined before the comparison, not improvised differently for the two groups. The plan records what actually happened. If a teacher must change conditions for welfare or safety, that takes priority; the resulting comparison then needs an honest limitation or a new design.
Actual blank recording sheet
| Container / treatment / position | Date, day and time | Emergence code | Observation and care actually completed |
|---|---|---|---|
| ________________ | ________________ | ________________ | ________________ |
| ________________ | ________________ | ________________ | ________________ |
| ________________ | ________________ | ________________ | ________________ |
Use Y for emergence observed by that visit, N for no emergence yet observed at a completed visit, and M for missing or unreadable evidence. Record the reason for M. “N by day 7” does not mean a seed is dead. Once a Y is recorded, retain that cumulative result; later shoot condition belongs in a separate note. This avoids confusing emergence with survival.
Completed simulated record
The fictional sowing is on 5 October 2026, day 0. Both later visits occur at 09:00: day 7 is 12 October and day 14 is 19 October. All containers begin with no shoot visible. The care log states that the teacher-set care protocol was completed consistently, with no recorded moves or departures. These are supplied model conditions, not independently observed facts.
| Container | Depth | Position | Day 7 | Day 14 |
|---|---|---|---|---|
| A1 | 10 mm | 4 | Y | Y |
| A2 | 10 mm | 1 | Y | Y |
| A3 | 10 mm | 6 | N | Y |
| B1 | 20 mm | 2 | N | Y |
| B2 | 20 mm | 5 | Y | Y |
| B3 | 20 mm | 3 | N | N |
Worked analysis and evaluation
By day 7, group A has 2/3 with observed emergence and group B has 1/3. By day 14, A has 3/3, or 100%, and B has 2/3, or about 66.7%. The endpoint difference is one container, about 33.3 percentage points. It is not a 33.3% difference in height: no heights were measured.
A suitable conclusion is: “More seeds had observed emergence by day 14 in the 10 mm group than in the 20 mm group in this small simulated comparison. The result is consistent with a depth-related difference under the supplied conditions, but three containers per group provide limited evidence. It does not identify the best depth for all seeds, demonstrate future yield or establish that B3 cannot emerge later.”
The design keeps the intended depth contrast clear and preserves each container’s record. However, seed-to-seed variation and position differences can still matter. Random allocation reduces deliberate placement bias; it does not make every position identical. A larger approved set of independently assigned containers and another comparable run would test whether the pattern persists. Rechecking the same container adds timing information, not a new independent replicate.
Independent planning and missing-data task
A proposed revision puts every A container at a bright window and every B container on a shaded shelf. Explain the problem and repair the allocation plan. In a separate version, B3’s day-14 observation is missing; B1 and B2 are still Y. State exactly what is known about the B group without substituting zero or assuming emergence.
Explained answers and review
The location change varies light conditions along with depth, so any difference cannot be attributed clearly to depth. Use comparable approved positions and random allocation across them, keeping the care and observation rules consistent and logging departures. Simply adding more containers in the same separated locations preserves the confounding.
With B3 missing, two of three assigned containers have documented emergence and one remains unresolved at day 14. The documented count is two; the complete-group emergence count could be two or three. Two Y results out of two available records is 100% of observed records, not proof of 100% emergence in the assigned group. Review for a clear unit, one intended difference, actual blank and completed entries, correct denominators and an evaluation that does not turn an invented study into crop advice.
Adult planning reference: RHS school-garden safety guidance identifies common hazards and the need for a site-specific risk assessment. It does not validate this crop model or a Kenyan curriculum allocation.
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