Agronomist Carlos Di Bella analyzes in his report for S4 some questions that the producer should ask in order to promote the use of climatic tools.
Every year, every agricultural campaign and every critical period, agricultural producers face climate uncertainty. Above all, that which is associated with the enormous inter-annual variability that exists today in relation to that of rainfall: its spatial and temporal distribution or its intensity.
As an example, in Chaco, from October last year to date, rainfall exceeded by far the historical average and even the maximum historical records. Excess surface water has a significant impact on an important productive portion of the province. But, in May 2018 in the same province 7 departments were declared within the agricultural emergency due to drought, with devastating losses in the agricultural sector.
In this context of high climatic volatility, the forecasts
are an indispensable diagnostic and planning tool. Earth observation satellites, atmospheric circulation models, big data, machine learning, among others, are some of the tools used.
In this context, the phenomenon “El Niño” plays an important role in current forecasts of climate in the medium and long term, especially for the prediction of rainfall and temperatures in our country that have so much impact on agricultural production.
In spite of having all the forecasting tools, it is very difficult to predict in an anticipated and reliable way. There are times of the year when predictions are less reliable, even in spite of the reliability in the occurrence of the event. Its impact on rainfall is very variable spatially and temporally.
María Elena Fernández Long, assistant professor of Climatology and Agricultural Phenology at the Faculty of Agronomy of the University of Buenos Aires, said: “The phenomenon of “El Niño-Oscilación del Sur” (ENOS) is, to date, one of the meteorological events with the greatest impact on inter-annual climate variability. This is why the scientific community has devoted itself to its study and, nowadays, it is possible to predict it several months in advance and with a very good degree of success. However, when analyzing its impact on agriculture in the Pampas region, it has been observed that it is only applicable for some areas and for some crops. This is because ENSO has a heterogeneous impact on the Pampas region, not only spatially but also temporally.
On the other hand, he indicated: “ENSO is the mode of climatic variability with the greatest impact on rainfall in the Pampas region”. However, when it comes to its impact on crops, the answer is, in many cases, weak or non-existent. However, there are other indices that can be used to analyze the water status of the soil and provide information on regional crop yields. In this sense, the Faculty of Agronomy of the University of Buenos Aires (FAUBA) developed a model of Operational Hydrological Balance for Agriculture (BHOA) from which is derived a water stress index that allows estimating crop yields on a regional scale.
According to the International Research Institute for Climate and Society (IRI-Columbia University- USA), most forecast models result in the continuation of a weak “El Niño” event towards the end of 2019. The same report concludes that there is a 70% chance of an El Niño event occurring during the June-August quarter and a decrease to 55-60% during the September-November quarter.
When these forecasts are transferred to the different regions, according to a report from the National Meteorological Service, the highest chances of above-normal precipitation are forecast for the center east, NEA and north. Through other forecasting centers, such as IRI or NOAA, the situation is similar.
REGIONAL FORECAST. Tips to consider ENSO by crop:
MAÍZ: In the region centered in the province of Entre Ríos, ENOS is a very good indicator of yields. Already in the month of September it begins to have a significant response. In La Pampa, it is only in November that this event begins to be an indicator of the result of yields. However, it tells us absolutely nothing in the southeast of the province of Buenos Aires.
SOYA: As with corn, ENSO has very heterogeneous and much weaker responses to this crop. In the province of Cordoba, ENSO’s response to soybean cultivation is clear and throughout almost the entire crop cycle. In the rest of the Pampean region the response is weak or null.
GIRASOL: The response of ENSO on sunflower is inverse and significant only in the province of Entre Ríos.
WHEAT: For this crop, ENSO does not serve as a prognostic tool in any area of the Pampas region.
Carlos Di Bella for Super CAMPO.