Water savings in agribusiness: how to irrigate with less water without losing yield

Water savings in agribusiness come, above all, from irrigation: irrigated agriculture accounts for more than half of the water withdrawn by economic sectors in Brazil, according to the country’s National Water and Sanitation Agency (ANA). Irrigating with less water without losing yield depends on two things: the right method for each crop and management that applies water when and in the amount the plant needs. In livestock farming and agro-industry, the rules of any operation apply: meter, find the losses and reuse.

In short:

• Irrigated agriculture accounted for 53.7% of the water withdrawn by sectors in Brazil in 2021, according to ANA.
• In the world’s irrigation systems, 15% is lost in conveyance, 15% in distribution and 25% in application: only 45% reaches the crop, according to ANA figures cited by Embrapa, Brazil’s agricultural research corporation.
• Efficiency changes with the method: 40% to 75% for surface irrigation, 60% to 85% for sprinklers and 80% to 95% for localised irrigation, such as drip and micro-sprinklers.
• For an irrigation of 4 mm a day, each percentage point of efficiency saves about 1,130 litres per hectare per day, by Embrapa’s calculation.
• For Embrapa, a high-efficiency system is useless if management is poor: soil moisture sensors, weather data and the soil water balance decide when and how much to irrigate.

How much water does agribusiness use in Brazil?

More than any other sector. According to ANA, total water withdrawal in Brazil reaches 96 trillion litres a year. Of that total, 30% is evaporation from reservoirs and 70% goes to sector uses. Among the sectors, irrigated agriculture took 53.7% in 2021 and, together with urban supply and manufacturing, accounts for about 84% of sector withdrawals.

The trend is upward. ANA projects a 30% increase in withdrawals between 2022 and 2040, with a large share from irrigation, and estimates that climate change could raise irrigation demand by 15% by 2040 compared with the trend, and by 20% in regions of mechanised irrigation, in a more critical scenario.

Irrigation pays: according to ANA, cited by Embrapa, each irrigated hectare equals three rain-fed hectares in physical productivity and seven in economic productivity. The question is not to irrigate less, but to irrigate better.

Which irrigation method uses the least water?

Localised irrigation, by drip and micro-sprinklers. Irrigation efficiency is the share of applied water the plant actually uses, and the document Manejo, eficiência e uso da água em sistemas de irrigação, from Embrapa Cassava and Fruits, gathers the ranges for each system:

Method	System	Efficiency
Surface	Corrugated furrows	40% to 55%
Surface	Border strips	55% to 75%
Surface	Furrows or level basins	60% to 80%
Surface	Surge flow	65% to 80%
Sprinkler	Traveling gun	60% to 70%
Sprinkler	Portable sprinklers	60% to 75%
Sprinkler	High-pressure centre pivot	65% to 80%
Sprinkler	Fixed sprinklers	70% to 85%
Sprinkler	Low-pressure centre pivot and linear move	75% to 90%
Localised	Micro-sprinkler	85% to 90%
Localised	Surface or subsurface drip	85% to 95%

Within each method there is a lot to gain. On centre pivots, lowering the emitters reduces wind losses: with sprayers at mid height, efficiency is between 80% and 85%; closer to the ground, between 85% and 90%; and with the LEPA system, which directs water into furrows, it can reach 90%. Subsurface drip exceeds 90% efficiency, because there is almost no evaporation.

The method is not chosen on efficiency alone. Localised irrigation suits vegetables and fruit best, which pay for the system, but it is already used for crops such as sugarcane, with subsurface drip. There is also energy: per cubic metre, sprinklers use 0.2 to 0.6 kWh, localised irrigation 0.1 to 0.4 and surface irrigation 0.03 to 0.3.

Why does management matter more than equipment?

Because the best system delivers little if water is applied at the wrong time or in the wrong amount. Embrapa notes that, in the field, efficiency falls below each system’s potential because of management: most irrigators do not have their system properly set up and do not determine precisely how much to replace or when. The crop’s consumption changes with its growth stage and the weather, and fixed management, copied from the design, tends to apply too much water.

The management tools, according to the document:

Tool	What it does	Watch out for
Soil moisture sensors (tensiometers, capacitance probes, TDR)	Indicate when to irrigate and help calculate the amount	They must sit in the zone where roots draw at least 80% of the water, at representative points in each plot
Reference evapotranspiration (Penman-Monteith method, FAO 56)	Estimates, with weather station data, how much the crop used	The precision of the weather data sets the precision of the irrigation amount
Soil water balance	Replaces water when the deficit exceeds the allowed limit	Deep percolation losses reduce precision
Uniformity assessment	Checks that water reaches the whole area evenly	Pressure, emitter spacing and wind change the result
Management apps	Do the calculations for the irrigator	Tools that are too complicated end up abandoned

Dividing the area into plots with similar soils and managing each one separately completes the picture. And in irrigation districts where water arrives in rotation, Embrapa points to switching to on-demand irrigation, in which farmers decide when they need water, as a substantial gain in efficiency.

How much do you save by improving irrigation efficiency?

A lot, because the calculation is multiplied per hectare and per day. Embrapa does the maths for an irrigation of 4 mm a day, equivalent to 40,000 litres per hectare: with Brazil’s average efficiency of about 59%, almost 68,000 litres are needed. Raising efficiency by one percentage point saves about 1,130 litres per hectare per day; over 1,000 hectares, more than 1.1 million litres a day.

Changing method yields more. By the same definition of efficiency, delivering the same 40,000 litres to the crop with a 70% system requires about 57,000 litres; with a 90% system, about 44,000, some 22% less.

The average hides regional differences. A 1999 survey, cited by Embrapa in 2013, estimated irrigation efficiency by region:

Region	Average irrigation efficiency
Northeast	65.8%
Southeast	65.5%
South	62.2%
North	55.1%
Centre-West	30.8%
Brazil	58.2%

These are old numbers, and the document itself notes the spread of higher-efficiency systems since then. But Embrapa’s conclusion still holds: water-use efficiency still does not get the attention it needs in Brazil, and what is spent on irrigation exceeds what crops consume.

How do you save water in livestock farming and agro-industry?

With the same fronts as any productive operation:

• Drinking troughs and float valves. A badly adjusted float valve overflows all day. Regular checks of troughs and water tanks are the cheapest measure.
• Dry cleaning before washing. In commercial kitchens, the EPA points to sweeping, squeegeeing and pressure washers as alternatives that use far less water than an ordinary hose. The same principle applies to pens, corrals and milking parlours: scrape and sweep before washing.
• Metering by area in agro-industry. In slaughterhouses, dairies and sugar mills, water is split between cleaning, cooling, boilers and processing, and each needs its own meter to show where the losses are.
• Cooling towers. Where there are any, raising cycles of concentration from 3 to 6 cuts make-up water by 20%, according to the EPA.
• Reuse. Treated process water can go back to yard cleaning, cooling and boilers, depending on the quality required. The step by step is in water reuse in industry.

How do you monitor water on a farm and in agro-industry?

By metering each abstraction point and each reservoir. Under Brazil’s Law 9,433/1997, abstracting water from rivers and extracting groundwater for use in a production process require a permit from the public authorities, except for uses deemed insignificant. The permit sets how much may be withdrawn, and the meter shows how much actually was.

In practice:

1. A meter at each abstraction point and each well, read frequently.
2. Reservoir levels and pump operation tracked remotely, to learn about a stopped pump or a reservoir emptying too fast before the damage.
3. Consumption per irrigated hectare or per unit produced, compared with the same period of the previous year.

T&D’s TDRR remote monitoring tracks the level of reservoirs and cisterns, pump operation and failure, and hourly consumption, with alerts by app, text message, email or WhatsApp. For agro-industry, SEA 360º handles implementation, with no construction work, with a baseline under the IPMVP protocol, electronic leak detection and repairs, followed by ongoing management with monthly efficiency and ESG reports. The full roadmap for any business is in the guide to water savings for businesses.

Frequently asked questions

Which irrigation method saves the most water?

Localised irrigation: drip, surface or subsurface, is 85% to 95% efficient, and micro-sprinklers 85% to 90%, according to Embrapa. Among sprinkler systems, low-pressure centre pivots and linear moves reach 75% to 90%. The choice also depends on the crop, the soil and the cost.

Does drip irrigation work for every crop?

It suits vegetables and fruit best, which pay for the system, but it is already used for other crops, such as sugarcane, with subsurface drip. For large grain areas, the low-pressure centre pivot is the highest-efficiency option among sprinkler systems.

How do you know the right time to irrigate?

With well-placed soil moisture sensors, in the zone where roots draw most of the water, and by calculating evapotranspiration from weather data. For Embrapa, using sensors to decide when to irrigate is beyond question, as long as they are in the right place.

Do you need a permit to irrigate in Brazil?

In general, yes. Law 9,433/1997 requires a permit to abstract water from rivers and extract groundwater for use in a production process, and exempts uses deemed insignificant. The permit is issued by the water management body: ANA for federal rivers and the state agency for state rivers and groundwater.

Will climate change increase irrigation water?

ANA estimates that irrigation demand could grow 15% by 2040 compared with the trend, because of climate, and 20% in regions of mechanised irrigation in a more critical scenario. Gaining efficiency now is the way to produce more without competing for more water.

Sources

• ANA, Base Nacional de Usos da Água e as Resoluções ANA nº 92 e nº 93/2021. SNIRH Bulletin No. 1, 2022, in Portuguese: total water withdrawal, irrigation’s share and projections to 2040
• Coelho, E. F.; Silva, A. J. P. Manejo, eficiência e uso da água em sistemas de irrigação. Embrapa Cassava and Fruits, Documentos 206, 2013, in Portuguese: efficiency by method and region, losses, energy, management and the value of each point of efficiency
• Law No. 9,433 of 8 January 1997, art. 12, in Portuguese: uses that require a permit
• EPA WaterSense at Work, section 4.8, Wash-Down Sprayers (2025): cleaning methods that use less water
• EPA WaterSense at Work, section 6.3, Cooling Towers: cycles of concentration
• T&D TDRR and SEA 360º