🧪 Inputs: fertiliser and chemicals

Buy on analysis and on proof, not on price alone

Counterfeit fertiliser and expired chemicals are common. Buy from registered suppliers, keep the receipt, and check the label and batch number.

• Read the analysis (for example N:P:K plus S and Zn) and compare cost per kilogram of nutrient, not per bag.
• Check the expiry date, the seal, the registration number and that the label is in English.
• Keep receipts and batch numbers — they are your only recourse if a product fails.
• Buy early. Prices rise sharply once the rains start and everyone is buying at once.

Fertiliser: right rate, right place, right time

Base your rate on a soil test and your yield target. Splitting nitrogen protects it from leaching and matches the crop's demand.

• Correct pH with lime first — fertiliser on acid soil is money poured away.
• Apply all phosphate and potash as basal at planting; band it, never broadcast on sand.
• Split nitrogen top dressing into two applications, on moist soil, and cover it where you can.
• Watch for deficiency signs: pale lower leaves (nitrogen), purple leaves (phosphate), leaf margin scorch (potassium), white striping (zinc).
• Include sulphur and zinc where the soil test shows a shortfall — small amounts, large effect.

Chemicals: identify first, then spray

Spray the problem you actually have. Correct identification, correct product, correct rate and correct water volume, applied at the right growth stage.

• Herbicides: pre-emergence needs moist soil; post-emergence needs small, actively growing weeds.
• Insecticides: scout weekly and use thresholds — fall armyworm needs early, targeted sprays into the funnel.
• Fungicides: mostly preventative. Once disease is widespread, you are limiting loss, not curing it.
• Rotate active ingredients between seasons to slow resistance.
• Never mix products unless the label or an agronomist confirms compatibility.

Mixing, calibration and safety

Most spray failures are mechanical: blocked nozzles, wrong pressure, wrong water volume. Calibrate before the first spray of the season.

• Calibrate: measure output per nozzle, walking or driving speed and boom width, then work out litres per hectare.
• Half-fill the tank with clean water, add product, agitate, then top up. Spray within the same day.
• Wear overalls, gloves, boots, goggles and a mask. No eating, drinking or smoking while spraying.
• Spray in the cool of the morning or late afternoon, never into wind toward homes, animals or open water.
• Triple-rinse empty containers, puncture them and dispose as the label directs. Never reuse them.
• Store chemicals locked, off the ground, away from food and feed, with the original labels intact.

Record every input

A written input record tells you your true cost per hectare, protects you in a residue query and helps an agronomist advise you properly.

• Log product, batch, rate, hectares, date and operator for every application.
• Keep the pre-harvest interval in mind before you sell or feed the crop.
• The FarmInvest app records inputs against each crop and adds them to your cost per hectare automatically.

Next in the farming cycle

• 🌍 Land and land preparation
• 🚜 Equipment and mechanisation
• 🌱 Crop choice and planting
• 🌾 Harvest, storage and selling

Crop guides

• 🌽 Maize
• 🍂 Flue-cured Tobacco
• 🫘 Soyabean
• 🥜 Groundnuts
• 🍅 Tomatoes
• 🫛 Sugar Beans