Argentine Soybeans Reviving with Late January, Early February Moisture
Argentine farmers are expected to bring in 48 million tons of soybeans for the 2011/2012 season, just over the production seen last year. Soybean area is expected to be 18.6 million hectares (ha) just 2 percent above last year’s soybean area of 18.3 million ha. Yield is estimated at 2.58 tons per ha (T/ha), just over a 4 percent drop from last month and 4 percent below the yield in 2010/2011 of 2.68 T/ha. Rains the next two months will determine the fate of the crop as the last week of January ended with only 40 percent of the second crop soybeans in the ground.
Most soybeans are now flowering and much of the crop has pulled out of severe stress as rains through January into February have encouraged better health for crop plants. The same regions with earlier dryness affecting corn had poor emergence and establishment of soybeans, namely northwestern Buenos Aires, southern Cordoba and far-south Santa Fe provinces but now are showing improvement.
For instance, around Junín in the province of Buenos Aires most soybeans only received about 5.6 millimeters (mm) or 0.34 inches of rain from the end of November through to December 20. Crop establishment had been poor for the early planted crop. In the areas hardest hit from lack of rain, leaves of the soybean plants appear smaller and crop plant internodes are short which have limited future plant branching and flower and pod set.
Recent rains, some have been 3 inches (76 mm), improved the crop but early planted soy still show damage that will limit final yield and production. Limited rain was seen through most of December. Additional moisture from the third week of January through mid-February has helped many regions—including the area of Junín in the province of Buenos Aires. Recent rains have greatly supplemented needed moisture.
Graph 1. AFWA/LIS precipitation data through 2012Jan31 for Junin, Buenos Aires, Argentina. |
Precipitation graphs one and two show rainfall received in Junín. Graph 1 includes both WMO (World Meteorological Organization) data and that received from the AFWA (Air Force Weather Agency) and is satellite-derived precipitation data to fill in between station readings. AFWA uses the Agricultural Meteorology modeling system (AGRMET) for near real-time access.
For precipitation, the program produces three-hourly fields of observed, estimated and merged (observed/estimated blend) precipitation. It retrieves observed precipitation (rain gauge reports) from AFWA’s global surface observation database and creates several estimates. All estimates are then placed into a hierarchy to establish that the most reliable data is used first and then this is processed further to complete a “best fit” estimate across locations.
Graph 2. WMO precipitation data from Argentina listed even less rainfall through their monitors during November, December and into January, making the precipitation accumulation very low in Junin, Buenos Aires toward the end of 2011--greatly affecting surface moisture.
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Graph 2 only includes the data from WMO which shows the situation through only WMO sites around the region, sites that are monitored through WMO’s Global Telecommunication System (GTS), a network of more than 6000 physical stations across the globe. Junín is one of the locations experiencing the dry conditions in December most intensely.
Despite surface moisture loss due to high temperatures during December and into January, subsoil moisture—in some locations--has been available to crop plants. Unfortunately with such high daytime temperatures, transpiration and growth and development of soybean and corn plants in the region that were established were affected. With temperatures above 86oF (30oC), crop plants often cannot transpire and take up moisture from ground supplies as efficiently nor as fast as needed—resulting in wilting or, in the case of corn, rolling of leaves. As drought stress continues, plants may limit growth and development—resulting in shorter internodes, smaller leaves or, in the case of soybeans, less branching.
Graph 3. Temperature maximums during the growing season so far with some highs in November, December and January, though short, may have affected the established soy crop plants in areas such as Junín, Buenos Aires.
Graph 4. Although some of the minimum temperatures seen in Junín did come down from daytime highs, the temperatures did not always drop low enough for long enough to help plants completely recover from the stress seen during the daytime.
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Graphs 3 and 4 show how the temperatures have varied in Junín, even with some subsoil moisture available, and crop plants have been stressed. Nighttime temperatures have been lower, allowing some crop plants to regain some turgor and bring some moisture back into the plant. Such high temperatures experienced—even during early growth and development will stress plants.
Graph 5. Cumulative moisture conditions in Junín in the province of Buenos Aires dropped very low from November through to mid-January. Some fields may have not been replanted in this region where soybeans have been lost.
Graph 6. It has been a battle on how low surface moisture conditions could get when comparing this year to last year. Newly established and early soybeans probably did have damage from lack of upper soil moisture as well as the high temperatures seen this year during December. |
Along with temperatures stressing the crop, some later planted soybeans were affected during establishment due to low surface soil moisture conditions. Even with some of the early season subsoil moisture conditions worse in 2010/2011 as compared to this year, later planted soybeans may have not had access to the deeper moisture reserves. The combination of temperature and moisture stresses may have permanently injured some soybean plants and may have lessened overall yield potential.
Graph 7. Subsoil moisture conditions in some regions such as Junín, Buenos Aires, has been better this season than last during December and January. High temperatures, however, had dropped moisture supplies and more rain is needed to help crops through to harvest. |
With lower temperatures at night, some recovery—if individual soybean plants had roots into the deeper moisture--may have occurred. Until another month has passed, it will be difficult to determine how much damage was done to the crop across the different provinces in Argentina and across the different soil types and water holding capacities as well as to the different temperature and moisture stresses and planting dates experienced by different fields and individual plants.
The soil moisture situation and water availability to plants will make a difference in how established, deep rooted, soybean plants were affected during the very high temperature periods. Over the next few weeks, the soy crop should reveal how much damage was permanent to crop yield from these extreme conditions. Rains this week and next will also determine if the rest of the second crop soybeans are well established and can complete maturity before a killing frost.
With mid-season subsoil moisture supplies not always better than last year in some locations, plants that were established and had a root system that could revive at night from deeper soil moisture supplies may survive but have yield damage. While temperatures have been tempered with recent cooling rains, it will still require additional moisture and lower temperatures through February and into March to help crop plants complete the season.
Some advisors within Argentina suggested that as much as 4 to 7 inches or 100 to 180 mm of additional rain was required at the end of January. A few locations have received recent, scattered, heavy rains but many sites still will need more moisture to refill subsoil moisture demands. Additional rain may also be required to encourage completion of late or second crop soybean planting in Argentina. (For more information, contact Denise McWilliams at 202-720-0107).
Current USDA area and production estimates for grains and other agricultural commodities are available on IPAD's Agricultural Production page or at PSD Online.
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