Research validates sugarcane irrigation method as a strategy for climate change

Technological package establishes water use levels in crops with a longer production cycle, such as sugar cane, and instructs how to do it

09.07.2024 | 13:42 (UTC -3)
Eliana Lima
Photo: Envato
Photo: Envato

Embrapa researchers devised an innovative set of parameters, coefficients and strategies for the efficient and sustainable management of sugarcane irrigation cultivated in the Cerrado. This is the BRCana Protocol, an agricultural practice of irrigation management for the production of sugar cane grown in that biome. The objective is to verticalize production, reduce the cost per ton and the susceptibility to water deficits accentuated by climate change. The techniques also increase the sustainability of sugarcane production, by reducing the demand for land and water, including a smaller water footprint than in rainfed production.

The technology recommends managing sugarcane irrigation using the combined method, which adopts the climate method as a base, but combines soil moisture and plant sensing as additional layers of information and measurement. It also recommends customized parameters focused on greater water use efficiency and the economics of sugarcane production in the Cerrado, including management in the growth and maturation phases (drying-off, in English).

According to Embrapa Environment (SP) researcher Vinicius Bufon, “BRCana has the distinction of being an unprecedented technical reference, with a solid and broad protocol for adopting an irrigated production system in the Cerrado, which allows substantially breaking levels of productivity, longevity and efficiency in the use of water and land”, he explains.

The way of producing sugarcane has changed radically in recent decades, but a technological package for irrigated production had not yet been developed for this scenario. According to the researcher, the completeness and solidity of the technology are conferred by two aspects: establishing the levels of water use for sugarcane irrigation that deliver greater efficiency and sustainability of this use and instructing how to carry out irrigation management for reach such levels.

Additionally, reports Bufon, BRCana allows the reduction of susceptibility to the increased frequency and intensity of droughts caused by global climate change. The researcher emphasizes that “despite being developed in the Cerrado, the technology can also be applied to other biomes and even other producing countries”, he adds. 

Photo: Envato
Photo: Envato

Validation of the method in sugar-energy plants

The agricultural practice was developed under a long-term experimental platform (since 2010), with a large geographic and edaphoclimatic range, giving perfect similarity to real production conditions. According to Bufon, the entire development process was carried out within sugar-energy plants, “under the research strategy (the end user acts as a co-participant in the development of the techniques), which gives high solidity and applicability to the technology”, he emphasizes. The adoption of irrigation in part of the sugar-energy plant area was highlighted as a strategy for adapting to climate change and increasing sustainability.

The irrigation operation, whether rescue or deficit, is complex, both from an operational and technical point of view, especially when applied to crops with a longer production cycle such as sugar cane. The process, under evaluation since 2012, has already been scaled up for commercial use, still under the supervision of Embrapa, at the plants of the Jalles Machado, São Martinho, Grupo Pedra Agroindustrial, Alta Mogiana, Raizen and Santa Adélia groups. With the adoption of technology, the average productivity of irrigated areas, in 12-year analysis cycles, jumps 70%, from 71 tons of sugarcane per hectare (t/ha) to 120 t/ha.

Irrigated production scenarios

The worsening of the climate crisis, with a prognosis of more frequent and intense drought events, results in increased risks to food security. In this context, national policies and international organizations point to irrigated production, conducted efficiently and sustainably, as one of the tools for mitigating climate change and supporting food security.

To demonstrate that irrigated production helps to mitigate climate change and increases the environmental efficiency of sugar-energy production, Bufon carried out a vision exercise on the sustainability standard desired in the plants, through the adoption of irrigation as a strategy to adapt to climate change .

He emphasized that adopting the strategy does not require irrigating most areas, nor does it require the adoption of full irrigation – which meets 100% of sugarcane's water demand. As an alternative, he indicated two paths. The first is rescue irrigation, a strategy that delivers only 3% to 4% of the crop's entire water demand, but guarantees the sugarcane field's sprouting under conditions of severe water deficit, ensuring adequate longevity, even after years of severe drought. .

The other strategy presented was deficit irrigation, by drip or pivot. It is called deficient because it delivers only 15% to 35% of the total water demand of sugarcane, but with great effects on productivity, longevity, land use efficiency, reduced cost per ton of sugarcane, in addition to reducing the demand for corrective agents. , fertilizers and diesel to produce each ton of the crop.

Considering real data from a plant in the region of Ribeirão Preto, SP, with crushing of approximately 5 million tons, the researcher presented two scenarios for adapting to climate change. In the first, 32% of the plant's area would receive irrigation, 5% with deficit drip irrigation, and 27% with rescue irrigation. In the second scenario, irrigation was adopted in 45% of the area, 8% with deficit irrigation and 37% with rescue irrigation.

In the first scenario, the study showed an increase of approximately 10% in land use efficiency, with savings in the cost of forming sugarcane fields and nurseries of around R$ 26 million per year, while in the second scenario, land use efficiency would increase approximately 20%, with savings of R$42 million in sugarcane formation costs per year. In the first scenario, the small irrigated fraction would be able to increase the average productivity of the entire plant by 3,9%, and longevity by 15%, while the second scenario would increase productivity by 4,2% and the longevity of the sugarcane field by 21%.

The 32% of irrigated area in the first scenario would cover the climate risk of 49% of own crushing, and 36% of total crushing, including sugarcane from suppliers. In the second scenario, the 45% of irrigated area would cover 66% of the mill's own crushing and 50% of the plant's total crushing against climate risks.

In the first scenario, a 12% reduction in the average radius would bring savings of R$12 million per year in transport costs and, in the second scenario, a 17% reduction in the average radius would bring savings of R$17 million, in addition to the entire reduction carbon dioxide (CO2) emissions from diesel used in transport. Bufon also showed savings of 14%, 13%, 6%, 4% and 7% in the consumption of limestone, gypsum, phosphorus, nitrogen and potassium, per ton of sugarcane produced, respectively, in addition to 6% of diesel and 7,8, XNUMX% ethanol and gasoline.

In scenario 2, savings jump to 19%, 18%, 8%, 6% and 10% in the consumption of limestone, gypsum, phosphorus, nitrogen and potassium, per ton of sugarcane produced, respectively, in addition to 7,7% of diesel and 10,2% ethanol and gasoline.

Bufon also showed that, if the plant chose to expand into new areas (horizontal expansion) instead of this investment in verticalization through irrigation of the smallest fraction of its areas, in scenario 1, it would be necessary to add 6.900 ha of land. The sugarcane formation cost associated with this horizontal expansion would be approximately R$110 million reais.

This alternative would still imply the loss of all land use efficiencies, reduced costs of crop formation, nurseries, etc. This would only be possible if there was available land in the plant's region. If the availability of land for expansion were in worse and more distant lands, an even greater quantity than 6.900 ha would be needed, and the demand for inputs and fuel per ton of sugarcane would also increase. In scenario 2, the demand for horizontal expansion would be 9.900 ha, with a sugarcane formation cost of approximately R$158 million.

“For the purposes of the agricultural technique in question, if adopted with correct parameters and strategies, and under a good regulatory and management framework for the rational use of water resources in the basins, irrigated production is more sustainable and efficient than rainfed production ”, he highlights.

Production sector approves

“I have been working with sugarcane irrigation management for almost 20 years, including as a partner with Embrapa in some experiments. We are currently monitoring more than 70 thousand hectares of sugarcane irrigated by the main irrigators in the sector, and we have observed a strong evolution in this period, and how some producers have stood out from the rest, by implementing a professional irrigation management system. Knowledge of water demand, the productive response to water deficit indicators and the drying-off strategy are essential factors for the productive and financial success of irrigated sugarcane enterprises”, highlights Sandro Batista Rodrigues, commercial manager at Valmont Indústria e Comércio Ltda. ., from Uberaba (MG).

“The company has been growing in the adoption of different irrigation methods. What sustains this growth is the adoption of appropriate techniques that allow for leveraging productivity, economic and environmental results. The adoption of the BRCana Protocol for recommending irrigation management for sugarcane production, from Embrapa, plays a decisive role in this process", says Caio de Toledo Piza, Technical Development supervisor at Raizen, Junqueira Unit (SP).

“As users, having reliable and rational technical parameters, which serve as a basis for using water management tools, are essential to guarantee an efficient operation, with reliable results, economically viable and environmentally sustainable. The parameters developed by Embrapa allow us to act efficiently and safely, by applying at the right time the volume of water necessary to meet our technical premises for mitigating water stress in sugarcane cultivation, with the security of results by we waited. Advanced water management, through validated technical parameters, is configured as a language of dialogue between the plant, users, and environmental bodies and regulatory agencies, allowing the company's water volume needs to be demonstrated in an assertive manner depending on soil and climate conditions. . Embrapa's research will also be used to plan water use and demand on a local (farm-plant) and regional (watershed) scale; assessments of water use efficiency in the sugar-energy sector, footprint and water scarcity studies; as a subsidy for the reformulation of the parameters for granting water use for sugarcane production at the National Water Agency (ANA) and state agencies; for studies and definitions of public policies; and use by socio-environmental production certification companies", concludes Lucas Farsoni Gallo, process analyst at the Corporate Agronomic Technical Department, at Usina da Pedra (Grupo Pedra Agroindustrial S/A), in the municipality of Serrana (SP). 

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