1. Industrial irrigation overview in Brazil
ANA's Irrigation Atlas, released on 26 February 2021, recorded 8.2 million hectares equipped for irrigation: 64.5% (5.3 million hectares) using water from natural sources and 35.5% (2.9 million) fertigated with reused water. Irrigated agriculture used more than 941 thousand liters per second in 2019, and the Atlas projects a further 4.2 million irrigated hectares by 2040, 79% above the current area irrigated with water from natural sources.
For center pivots, ANA published an updated mapping in November 2023, with 2022 data: Brazil exceeded 30 thousand pivot points and 1.92 million equipped hectares, 24% more than in 2019. Six states hold 92.5% of that area: Minas Gerais (29.2%), Goiás (16.3%), Bahia (15.3%), São Paulo (12.9%), Rio Grande do Sul (10.2%) and Mato Grosso (8.6%).
The Cerrado accounts for 70.4% of the total, and Paracatu (MG), Unaí (MG), Cristalina (GO), São Desidério (BA) and Barreiras (BA) lead in equipped area.
These are 2019 and 2022 references, not 2026 measurements. For the farm design, the decisive data are water availability, crop, irrigation scheduling and demand in critical periods.
Pivot, drip, sprinkler and surface irrigation each have their own demands. FAO relates pumping capacity to area, gross application depth and available time. Illustrative example: 100 ha × 5 mm/day × 10 ÷ 0.80 ÷ 20 h/day = 312.5 m³/h, assuming an overall application and distribution efficiency of 80%. These values are assumptions of the example; the agronomic plan must set the actual depth, efficiency and operating hours.
Engineering note
For a quotation, send flow per sector and simultaneity, available hours, minimum and maximum water levels, the elevation of the delivery point, piping, filters and the pressure required by the irrigation system.
2. Surface intake station — the core of the operation
Rivers, reservoirs and canals can vary in level, availability and sediment load. Survey dry-season and flood conditions, the water analysis and the intake restrictions. A selection based only on the level seen during the site visit may not represent suction throughout the whole season. Deep wells require their own assessment and are not treated here as an automatic FBCN application.
In a fixed or floating station, check available NPSH, intake submergence, air entry and suction head loss. Following the river level with a platform does not eliminate cavitation. Foundation, piping, check valves, debris protection and any parallel operation need design; a pontoon also requires structural and mooring assessment independent of pump selection.
Altitude weighs on suction. According to the U.S. Standard Atmosphere, 1976, atmospheric pressure falls from 1,013.25 hPa at sea level to 898.76 hPa at 1,000 m. With water at 25 °C (vapor pressure of 3.17 kPa and 997 kg/m³, from NIST), the difference between atmospheric and vapor pressure is about 10.0 m of water column at sea level and 8.9 m at 1,000 m.
The height of the pump above the water and the suction losses come out of that value; what remains is the available NPSH.
Example with stated assumptions: at 1,000 m, with the pump 4 m above the minimum level and 1 m of suction losses, available NPSH is about 3.9 m. The published FBCN 125-315 curve at 1,750 rpm (CC-136.07, 332 mm impeller, clean water at 20 °C) requires an NPSHr of about 3 m at 300 m³/h, leaving less than 1 m of margin.
If the river drops another 2 m in the dry season, the available value falls to about 1.9 m, below the curve NPSHr, and the pump runs with cavitation, which begins before that point. That is why selection starts from the minimum level, with margin.
An irrigation intake is an open system: besides losses, the pump overcomes the elevation difference between the water and the delivery point (Improving Pumping System Performance, the US DOE and Hydraulic Institute sourcebook, p. 8). The same sourcebook points to parallel pumps for systems with high static head, with the benefit of redundancy: one can be taken off line for maintenance while the others support operation (p. 9).
Define how many pumps operate from the system curve and the demand scenarios, including sectors that are shut off. Do not add nominal flows without checking parallel operation. Model, impeller diameter, speed, motor, materials and sealing must appear in the proposal. The FBCN manual states mechanical construction conforming to ASME B73.1; this does not establish dimensional interchangeability with any installed pump.
3. Center pivot pump: pressure at the critical point
The station must supply the emitter set specified in the pivot design. Gather the equipment demand curve, the terrain profile and the conditions of simultaneous operation of other pivots. The pressure required at the emitter is not the same as the pump discharge pressure: between them lie elevation differences, piping and fittings.
Use the pressures and flows published by the emitter manufacturer, without applying a single range to every pivot. Assess the least favourable topographic position and the losses up to that point. The pump curve must cover the duty within a suitable operating range and NPSH; performance testing and records must be defined in the contract.
To quote the pivot pump, send, from the pivot manufacturer's data sheet, the design flow and the pressure required at the inlet; the elevation of the pivot point and of the minimum water level; the length, diameter and material of the supply main; how many pivots run at the same time; and the available power supply. With these data, FB checks the point on the FBCN curve, the NPSH at the intake and the motor.
When several pivots take turns on the same supply main, flow changes during the day. The DOE sourcebook names speed adjustment as the most efficient means of controlling flow, but advises caution where static head is a large portion of total head: slowing the pump could induce vibration and problems similar to operating against shutoff head (p. 51). In that case, also compare splitting the duty between parallel pumps.
4. Drip and fertigation: filtration and materials
In drip irrigation, clogging can change flow and distribution uniformity. Embrapa highlights physical, chemical and biological agents and the need to analyze the water before installation. The filtration rating must follow the emitter and the water quality; there is no universal micron cut-off that solves every system.
Include the losses of the filter assembly in the pump head, considering the cleaning cycle defined by the supplier. Also state backwash flow and pressure, simultaneous sectors and the regulation strategy. A filter selected in isolation can change station demand when it goes into cleaning. Valve control and variable speed should be compared for this actual sequence.
Distinguish the water pump upstream of injection from the one that receives fertilizer solution. For direct contact, send composition, concentration, temperature and safety data sheet; pH alone does not define the compatibility of casing, seal and elastomers. The FBCN manual lists cast iron, WCB and CF8M constructions, without approving any mixture. Embrapa also advises checking solubility and compatibility between fertilizers to avoid precipitates.
On the FBCN with packing, the seal chamber changes with the fluid (MTEC-03/00 manual, item 10). The standard ST arrangement serves clean, non-aggressive fluids. S3, flushed with clean liquid from an external source, is the one indicated for abrasive particles in suspension or a risk of crystallization, the situation of sandy water or of a solution that tends to precipitate. With a mechanical seal, the arrangement follows the application (line S of item 10).
For fluids with suspended solids, the manual asks for FB to be consulted (item 2.3); send the sediment analysis of the intake.
To transfer the concentrated solution, FB also has the FBE external gear series, which the 2026 FBE catalog lists for fertilizers (Chemical card, p. 3). Centrifugal or gear depends on the flow, the viscosity and the safety data sheet of the solution; the FBE manual also asks for FB to be consulted when the fluid carries suspended solids (MTEC-01/01, item 2.3).
5. Energy efficiency and solar operation
Compare consumption with energy and volume measurements: kWh/m³ lets you track the station under equivalent level, flow and pressure conditions. Assess the efficiency of pump, motor and control, and the network losses, at the points actually used. Savings and payback depend on local tariff and hours; they cannot be promised as a fixed percentage for replacing the pump.
Energy per cubic meter comes from head and efficiency: E (kWh/m³) = ρ · g · H / (3.6 × 10⁶ · η). With water at 25 °C (997 kg/m³, from NIST) and g = 9.80665 m/s², every 10 m of head costs 0.027 kWh/m³ of hydraulic energy.
At the best efficiency point of the FBCN 125-315 at 1,750 rpm, near 320 m³/h and 51 m with 82% on curve CC-136.07, the pump takes about 0.17 kWh/m³ at the shaft, before motor and drive losses.
In the section 1 example (312.5 m³/h for 20 h, or 6,250 m³ per day), that comes to about 1,060 kWh per day at the shaft, if the pump runs near that point. Every meter of head avoided, in head loss in the supply main, filters or valves, reduces hydraulic energy in the same proportion. That is why proposals should be compared at the same flow, the same head and the efficiency read on the curve of the model offered.
Where there is photovoltaic supply, compare the required daily volume with the available energy and the water storage capacity. The pump, motor and drive set must have speed limits approved for the configuration, including minimum flow, power and NPSH. No universal 50% to 110% range is adopted, nor is constant efficiency assumed across the whole variation.