Agricultural spray tanks: choose capacity and a complete liquid system
Choose an agricultural spray tank as part of the complete liquid-delivery system. Compare working capacity, filling access, agitation, level indication and controlled draining alongside the pump and filters. Identify separate tanks for spray liquid, equipment rinsing and personal washing, plus any induction hopper.
The main tank holds spraying water or diluted pesticide. The rinse tank supplies water for washing the main tank. A separate personal-washing tank supplies the operator. An induction hopper transfers concentrated product into the liquid circuit. Compare these components in the proposed installation.
Compare total tank volume with the marked maximum working fill. Check that the liquid-level indicator remains visible during filling and from the operating position.
For an offer described as a 100 ltr spray tank, a 100-litre spray tank, a spray tanker or a 40 gal sprayer, confirm the unit standard and marked working capacity. A US gallon is 3.785412 litres and an imperial gallon is 4.54609 litres, so a 40 gal sprayer holds about 151 litres if the gallon is American and about 182 litres if it is imperial.
Try the lid and closures with gloved hands. Check that the lid seals closely and the filling strainer fits securely. Remove and refit the strainer to assess access for cleaning.
Check how the pump supplies agitation while maintaining application output. Equipment controlling concentrated product and diluent separately has different agitation needs. Ask for a demonstration of the complete circuit.
Check how tank drainage is collected or discharged for safe disposal. Inspect low points, valves, filters and hoses for cleaning access. Avoid awkward recesses and rough surfaces that retain residues.
The same sprayer may apply insecticides, foliar fertilizer, fungicides and herbicides in one season, so plan the rinse between products. Keep the personal-washing tank and pipework isolated from the spray circuit. Use the rinse tank for equipment cleaning. Identify both outlets clearly before filling.
Check the durability of exposed surfaces and their resistance to pesticide formulations, sunlight and weathering. Include seals, filters, valves and pipework in the assessment of wetted components.
An induction hopper receives concentrated formulation and uses water to dissolve or dilute it before transfer. Check the manufacturer’s procedure for liquids, powders, granules and soluble packaging. Keep the operating instructions with the installation manual.
Check the connections around the tank as well as its shell. Filters should be accessible for cleaning without emptying the tank. Look for durable hose pressure markings and routing without kinks. A non-return valve prevents backward siphoning through filling pipework. For hydraulic nozzles, check that the pressure gauge is visible and gives a stable reading.
Check mounting, filling and service access
Inspect the tank installation on the tractor or trailer. Check secure attachment, guarded shaft drives and protection at boom-folding and height-adjustment trapping points. Locate handles away from hinged joints. Ask the supplier to demonstrate deployment and adjustment while you watch the clearances around the operator.
For manual chemical filling, check access from the ground or a purpose-built platform. Try the reach to the opening while wearing the specified protective clothing. Keep the pouring zone unobstructed. Compare the stated filling rate with the filling arrangement and look for splash or overflow risks.
Check the equipment identification plate for manufacturer, model and year of manufacture. Request illustrated procedures for assembly, decontamination, spare-parts identification and safe use. Include nozzle selection and handling of undiluted formulation in the handover, and locate the controls from the normal working position before accepting the installation.
Shutoff valves and pump identification
Identify the independent boom-section valves and the master shutoff. Check the anti-drip devices at the nozzles and where the pressure-relief circuit returns liquid. Inspect hose routing around the cab and guards protecting the driver against a burst. Read the pump plate for its serial number, maximum flow, pressure and recommended rotational speed. Compare that identity with the pump shown in the quotation.
Calculate the cost of a spraying job on your Malta farm
Spraying cost per hectare = the cost of the whole job divided by the hectares treated. Add the product used, labour, energy, consumables and the equipment cost you choose to allocate. List the costs included in your estimate before comparing it with a contractor's quote. Separate annual ownership expenses from expenses that change with machine use.
Choose whether you need a cash-spending figure or a fuller equipment budget. Include depreciation, capital cost, insurance and housing when allocating ownership costs. Enter your own values beside each cost category.
Include travel and servicing in labour time as well as time spraying in the field. Use measured job records to estimate those hours.
List actual fuel, charging, water and other job expenses with units and prices. Mark expenses already included in an equipment rate. When costing a tractor and implement together, count the operator and fuel once.
Identify the expenses included in the machine’s hourly allowance. Keep routine repairs separate from a purchase or major rebuild. Estimate repairs from the farm’s detailed servicing history where available.
Divide annual ownership cost by annual hours of use to calculate an hourly allowance. Multiply that allowance by machine hours assigned to the job. Keep annual use and the ownership total as separate inputs.
For straight-line depreciation, subtract expected resale value from initial cost and divide by the years of useful life. Write down each assumption so the estimate can be recalculated when the offer or expected use changes.
Spreading annual fixed costs over more work reduces the fixed cost per hour. Compare the hours you expect to use with work already secured before budgeting a purchase. Compare purchase, leasing and custom hire using the same workload and chemical-supply assumptions, with dated local quotations for each.
Use local tax bills and lubrication records alongside fuel and repair expenses in the equipment budget.
Distinguish historical purchase price, current used value, expected resale value and equivalent replacement cost. Label each input in the worksheet, note the valuation date and use the value the particular calculation requires.
Record time spent applying, turning, filling, adjusting, waiting and travelling. Turning, overlap, adjustment and filling reduce effective field capacity. Divide completed area by actual job hours to compare planned capacity with recorded work.
Capital tied up in the sprayer
Invented example: a complete installation costs €4,000, is expected to sell for €1,000 after five years, and is assigned a 4% annual capital rate. Straight-line depreciation is (€4,000 − €1,000) ÷ 5 = €600 a year. Average-value capital cost is (€4,000 + €1,000) ÷ 2 × 0.04 = €100 a year. The subtotal is €700 before insurance, housing and operating expenses. At 100 machine hours, that subtotal contributes €7 per hour; at 50 hours, it contributes €14. Use local purchase and finance figures for your own calculation.
Economic life is the planned ownership period; service life is how long the machine can physically remain usable. A replacement decision can therefore occur before the sprayer is worn out. Salvage value is the expected disposal or trade-in receipt at that planned endpoint. Use the intended replacement date when entering these assumptions.
Compare width, speed and effective field capacity
Calculate theoretical coverage in hectares per hour by multiplying working width in metres by travel speed in kilometres per hour, then dividing by ten. Multiply that result by field efficiency expressed as a decimal to estimate effective capacity.
Invented example: a six-metre boom travelling at five kilometres per hour gives three theoretical hectares per hour. An assumed efficiency of 0.60 reduces effective capacity to 1.8 hectares per hour. Divide the complete hourly equipment charge by that effective figure when comparing a wider installation with a contractor's offer. Measure the actual utilisation on small parcels, including headland manoeuvres and refilling delays, before using the estimate for pricing.
Compare finance and replacement assumptions
Capital tied up in equipment has a cost. For borrowing, use the loan’s interest rate. For your own capital, compare the return available from its next best use. Keep that financing assumption separate from diesel, electricity and repair expenses.
Depreciation captures losses from age, wear and obsolescence. Check the expected resale condition when comparing a cheaper used sprayer with a new installation, and keep the same ownership period and workload across alternatives.
For contract work, write down whether the quoted service includes chemicals and an operator, and compare that bundle with the farm’s own spraying budget. Include the cost of keeping equipment available while it sits idle.
Next step
Ask suppliers to quote the same complete installation. For a portable machine, use the knapsack sprayer guide to compare delivery and maintenance. Use the spray tank calculator for job quantities and the application-record guide for the completed treatment.
