Extreme drought reduces sugarcane productivity and brings forward harvest

A survey by the company Centro de Tecnologia Canavieira (CTC) indicated a drop in productivity per hectare in sugarcane harvested in the center-south region of the country, with an average of 69,7 tons per hectare (t/ha) in September 2024, compared to the same month in 2023, when there was an average of 83,4 t/ha. This week, the employers' association União da Indústria de Cana-de-açúcar e Biotecnologia (Unica) indicated an advance in the harvest in the state, with 12 units finishing milling by the second half of October. In the same period of the previous harvest, four mills had completed milling.

The company, which monitors the development of technologies in the sector, observed a slight gain in the quality of the raw material through the measurement of Total Recoverable Sugar (ATR) in the harvest, slightly higher in 2024, with 136,71 kg per ton of harvested sugarcane. Unica observed a faster improvement among its associates, with 160,30 kg of ATR per ton of sugarcane this year against 149,84 kg per ton in the 2023/2024 harvest - a positive variation of 6,98%. In the accumulated harvest, the indicator was 142,23 kg of ATR per ton, an increase of 1,03% compared to the same period last year.

Unica reported that 255 production units operated in the center-south region in the first half of October, of which 236 units processed sugarcane, nine companies produced ethanol from corn and ten flex plants. In the same period, in the 23/24 harvest, 259 production units operated. The association also showed that, in the first half of October, production units in the center-south region processed 33,83 million tons, while in the previous harvest they had processed 32,93 million. The increase was 2,75%. In the accumulated total of the 2024/2025 harvest up to October 16, milling reached 538,85 million tons, 2,36% more than the 526,43 million tons recorded in the same period of the previous cycle. Experts attributed the increase to an advance in the harvest, a measure used to avoid greater losses in productivity.

Expected decrease 

According to Maximiliano Salles Scarpari, a researcher at the Agronomic Institute (IAC) of the São Paulo State Department of Agriculture and Supply, monitoring carried out by the PrevClimaCana project, in which he participates, indicated a result below 2023 in the first quarter. He highlighted that the deficit had already been abnormal since December 2023 and became more pronounced in the period between March and October 2024, being the longest measured by the IAC since 1934, when the institute's series began. As 2023 had a good water supply and a high ratio of tons of sugarcane per hectare, the crop failure became even more evident with this year's extreme drought.

Maximiliano explained that increasing the milling rate is a common strategy in the sector, which adapts the harvest to take advantage of the most favorable moment, changing the planning within the harvest. "The mills are anticipating areas, and the harvest yield within the harvest was good. In the future, the tendency is that they will have more time to prepare for the next harvest, with maintenance of harvesting and milling equipment", said the researcher, highlighting that the continuation of a drought scenario should lead to a second affected harvest, since the sprouting, which is already starting now, was impacted. The extent of this damage, however, will only be measurable from mid-December onwards and, more clearly, at the end of the first quarter of 2025.

"This year, sugarcane has practically been harvested, as it was a year of high water deficit. Few areas have not yet been harvested, and the trend is for the crop to close with low t/ha, which, depending on the stock, could impact the price of sugar and ethanol. There is no way to reverse this, but it can be mitigated with irrigation techniques," Scarpari added. This strategy, however, will depend on the granting of new water use permits, which, at least in São Paulo, have been authorized in a careful manner and give preference to use in supplying cities. For producers, he adds, an alternative that has been discussed and even advised is the use of parametric insurance by producers, based on productivity criteria, whether in quantity (for t/ha) or quality (for ATR). This measure mitigated the impact, especially in the face of fires, which the sector attributed to an impact of around R$1 billion in losses this year.

Sugarcane preparation

Brazilian sugarcane varieties are selected to tolerate drought conditions, according to researcher Vinicius Bufon, from the Brazilian Agricultural Research Corporation (Embrapa Meio Ambiente). Since more than half of the production of the raw material occurs in areas of cerrado or transition to cerrado, with concentrated rains and droughts that vary over a period of five to seven months, the plant is quite hardy and survives the elements, but "there will always be a reduction in production potential as a consequence. This worsens as sugarcane production migrates to the more inland cerrado, but also in traditional producing regions, as climate change brings more frequent and more intense drought events," warns Bufon.

He noted that a drought like this year's could lead to even greater losses, which is what happened in some of the plants monitored, where more than 15 t/ha were lost between 2023 and 2024. There are technologies, with recommended application for crops, that can alleviate the scenario, especially the adoption of irrigation in part of the production. "The irrigated production system can be adopted, mainly, in two modalities. The first is rescue irrigation, which delivers a single application of water, immediately after harvest, of around 30 to 60 millimeters (mm). This corresponds to approximately 4% of the crop's water demand during a harvest, but has a great effect on ensuring sprouting. The second alternative, called deficit irrigation, or controlled deficit irrigation, delivers 20% to 25% of the crop's water demand during the harvest", he argues.

The difference, according to the researcher, is that the rescue irrigation method can be adopted in 30% to 50% of the crop, especially in sugarcane fields harvested from May to September, the driest period, while the deficit irrigation technique could be adopted in 5% to 15% of the crop, especially in sugarcane fields with more limiting, sandier soil, in the period from July 15 to September 15, historically the most critical in cerrado regions. "The rest of the sugarcane field, from 40% to 70%, could be strictly dependent on rain, but harvested in the wettest parts of the harvest, from March to May and from September to November," he adds.

Embrapa does not recommend the use of full irrigation under any circumstances and always after analysis by regulatory agencies, which has favored the recognition of irrigated production techniques as a sustainable tool worldwide. "The inflationary pressure experienced in each of these drought events tends to accelerate the process. And this expectation is not limited to Brazil. The world expects a lot from Brazil to meet the growing global demand for food security and biofuels, for example. Fortunately, we have sustainable technology to offer, we have innovative and competent farmers, and we hope that the framework of public policies and lines of financing can create the incentives and legal security necessary for producers to take the risk of investment that, despite being very viable, requires a lot of investment", recommended Bufon.

Exploration permits were suspended during some critical periods, mainly in São Paulo, and the recovery of the level of wells in the main aquifers has not occurred every year.