The methods we teach, what each one costs, and what it returns. Every figure on this page is reproducible from a paired demonstration plot and a farmer-held ledger.
Each practice is demonstrated against a farmer control plot on the same soil, in the same season, with the same rainfall. That pairing is what makes the comparison defensible.
Weeds compete for moisture during the vegetative window, the same period the crop establishes its root system. ZIAP trains removal before canopy closure rather than after weeds have drawn down available water.
Broadcast application produces uneven plant populations and uneven access to moisture. Farmers set a string line at 75 cm rows and 20 cm within-row spacing, then place seed and fertilizer by hand along it.
Urea applied at planting loses a meaningful share of its nitrogen to volatilisation and leaching when rainfall is intermittent. ZIAP delays top-dressing until rainfall probability and crop stage both support uptake.
Every household on a demonstration plot keeps a cost and return ledger in a standard spreadsheet template, covering inputs, labour, and harvest value by plot. Financial instruction runs alongside agronomy, not after it.
Switch between the three views used in our field review. Values are per hectare and expressed in US dollars at the 2026 program exchange rate.
| Practice | Added cost (USD/ha) | Yield delta (t/ha) | Value added (USD/ha) | Net margin (USD/ha) |
|---|---|---|---|---|
| Early weed control | 48 | +0.71 | +192 | +144 |
| Even spacing (string line) | 11 | +0.34 | +92 | +81 |
| Delayed urea timing | 0 | +0.28 | +76 | +76 |
| Combined protocol | 59 | +1.33 | +360 | +301 |
| Control (household practice) | 0 | baseline | baseline | baseline |
| Program total, 2025-26 | 59 | +1.33 | +360 | +301 |
Mailage valued at a conservative USD 270 per tonne. Marginal values are additive with diminishing returns at full protocol adoption; combined row is measured, not summed.
They are ranked by return per dollar, not by visibility. Weed control leads because it costs labour the household already owns and protects the moisture that every later input depends on.
| Input | Household rate | ZIAP recommended | Trial yield (t/ha) | Input cost (USD/ha) |
|---|---|---|---|---|
| Maize seed (kg/ha) | 28 | 20 | 5.61 | 96 |
| Basal fertilizer (kg/ha) | 150 | 150 | 5.61 | 82 |
| Urea top-dress (kg/ha) | 150 | 100 | 5.61 | 54 |
| Target population (plants/ha) | uneven | 44,000 | 5.61 | 0 |
| Total input cost | 315 | 232 | 5.61 | 232 |
Reducing seed and urea rates cut input cost by USD 83 per hectare while yield rose, because plant spacing and application timing improved. This is the core of the optimization argument.
| Entry | Date | Cost (USD) | Labour (days) | Note |
|---|---|---|---|---|
| Seed, 20 kg | Nov 14 | 96 | 2 | String-line spacing |
| Basal fertilizer, 150 kg | Nov 14 | 82 | 3 | Banded in-row |
| First weed pass | Dec 02 | 0 | 11 | Within 14 days |
| Urea top-dress, 100 kg | Dec 22 | 54 | 2 | Delayed 30 days |
| Second weed pass | Jan 09 | 0 | 9 | 35-day window |
| Harvest | Jun 18 | 232 | 27 | 5.61 t/ha at USD 270/t |
Gross value USD 1,515. Net margin USD 1,283 before household consumption. The household computes this itself each season; our role is the template and the arithmetic lesson.
Households keep the ledger after program support ends. In the 2025-26 follow-up survey, 78% of graduating households submitted a self-computed margin without staff assistance.
Credit is useful only when it finances an input the household can already show returns for. Loans are sized against the recorded margin, never against the requested amount.
$186,400
Disbursed, 2025-26
94%
Repayment rate
4.2 mo
Average term
71%
Borrowers with prior ledger
Loan size is capped at a share of the margin the household demonstrated in its own ledger over the prior season. A borrower with no record receives a smaller first loan and a ledger training requirement before any increase.
Repayment rests with the village savings group that administers the loan, not with individual land collateral. Group treasurers keep the register and report monthly to the field team, which is why the repayment rate holds through a poor harvest.
A verified crop failure triggers term restructuring rather than enforcement. Because the ledger documents labour and input timing, the field team can distinguish a genuine failure from a payment default, and the two are handled differently.
Plot-level records, rainfall logs, and household ledgers are available to academic partners under a data-sharing agreement. Requests go through the collaboration form and are reviewed by the board treasurer before release.
Funding a demonstration plot costs less than a season of imported inputs, and it leaves a paired control and a household ledger behind.