Better questions. Better field decisions.

Free guides to use alongside your measurements and local agronomy advice.

Open field planners

01 / IRRIGATION

Read the water balance, then check the soil.

Weather changes the amount of water a crop uses. Reference evapotranspiration (ET₀) represents atmospheric demand; a crop coefficient adjusts that demand for a crop and growth stage. Multiplying the two gives an estimate of crop water use.

Crop water use = reference ET₀ × crop coefficient

Start with an estimate of water already depleted from the root zone. Add crop water use, then subtract effective rainfall and net irrigation. Compare that balance with a locally appropriate depletion threshold. A calculated trigger is a reason to check the field: verify soil moisture, rooting depth, emitter performance and infiltration before deciding how much to apply.

AGGI’s planner shows these inputs explicitly. Its simplified balance excludes capillary rise, salinity and reduced water use under stress. Ponded rice requires a different water plan.

Reference: FAO Irrigation and Drainage Paper 56 ↗

02 / FERTILIZER

Separate the nutrient requirement from the product amount.

A soil test needs local interpretation for the crop, yield conditions and sampling method. An analytical result in parts per million is not itself a fertilizer application rate.

Once you have a nutrient recommendation, account for available nutrient credits from manure, previous applications or other locally assessed sources. Then convert the remaining requirement using the product’s nutrient analysis. For example, a remaining nitrogen requirement of 20 kg/ha and a 20% nitrogen product gives 100 kg of product per hectare. This is a unit-conversion example, not a crop recommendation.

Product rate = remaining nutrient rate ÷ nutrient fraction

Keep nitrogen (N), phosphate (P₂O₅) and potash (K₂O) distinct. Blended fertilizers supply several nutrients, so check every component before applying. Review rainfall, runoff exposure, access conditions and product directions when scheduling work.

Reference: University of Minnesota Extension soil-test guidance ↗

03 / PESTS & PESTICIDES

Start with a scouting record.

Record the crop stage, affected plants, visible damage, counts and sampling method. Look for beneficial organisms too. Pest identity and a locally appropriate action threshold determine whether a response is needed; a weather forecast alone cannot supply either.

When a threshold is exceeded, compare cultural, mechanical and biological controls. If a pesticide is part of the response, verify that the product is registered for the jurisdiction, crop and target pest. Use the current label to check application rates, protective equipment, worker re-entry, preharvest intervals, weather restrictions, buffers and pollinator protection.

AGGI turns observations into a scouting checklist. It does not choose pesticide products, prescribe doses or certify a spray window. Record follow-up observations to evaluate the result and discuss resistance management with a local adviser.

Reference: EPA integrated pest management principles ↗

Educational guides prepared September 2026. Core tools remain free. Advertising has no role in the order or content of agronomic recommendations.