The thick campaign is in overdrive in San Luis. Spurred on by the summer rains, which this year arrived in time to overcome the hard slope in which the drought had plunged the countryside, which lasted well into October, soybeans and corn already cover the most productive plots in green.
To learn specific details about each area, the magazine El Campo consulted two agronomists who advise producers in the Conlara Valley and the central-east region (Pueyrredón, Pringles and Pedernera departments). Each one has its peculiarities, so it is possible to draw a broad panorama and imagine what the final result may be, although the weather will always have the last word in terms of performance.
Conlara Valley
“With a very complicated year like 2020, a few months ago a marked reduction in the area planted in grain crops for harvest was estimated. Many tenants from other provinces, mainly Córdoba, had not been able to enter due to the restrictions imposed the pandemic. They also played against Argentina’s almost permanent unfavorable economic measures and the low yields of the previous season. But against all forecasts, the planted area has reached the levels of previous seasons, although in general with less investment in technology applied to crops, “says Marcelo Bongiovanni, an agricultural producer from Tilisarao, who is a teacher at the UNSL and has a business that sells inputs for the field, so he takes the temperature of the sector first-hand.
He acknowledges that “the start of the campaign was complicated by the lack of early rainfall in spring and the scarce water reserves in the soil. In the best of cases, at the end of October there was 40-50 millimeters (mm) of useful water in the first two meters of ground “. This was due to the fact that 2020 was one of the driest in the last 30 years, with records that ranged from 380 to 540 mm, well below the historical average for the area, which is around 690 mm per year.
In the Conlara Valley there is an advance of “hard weeds”, such as the Cortadera Chica (Pappophorumsp) that is very difficult to control.
“The rains began at the end of October, with records between 30 and 60 mm, which allowed the beginning of the sowing work and the applications for weed control. In November, the rains were below average, but the 70 to 90 mm fallen allowed us to advance. In December, the situation was complicated due to the scarce rainfall, high temperatures and high incidence of winds, which made it impossible to carry out the applications for weed control in a timely manner, which then began to compete for water and nutrients with the crops, “describes Bongiovanni.
Fortunately, the situation changed between Christmas and New Year, with rainfall (20 to 60 mm) that determined a noticeable improvement in the implanted crops and allowed the postponed planting work to be completed. “The arrival of the new year brought good rain records (between 30 and 90 mm, depending on the locality) that recharged the profile and gave a good condition for the growth of the crops. But the campaign has just begun and it is necessary that the contributions January, February and March water levels are, at least, within the average values to close with good yields, “he warned.
A separate chapter is the agricultural lots, which were affected by the fires in early spring. “In Conlara, around 13-14 thousand hectares suffered total damage. These plots were sown with the first spring rains, but between the lack of water and the strong winds of November and December they suffered important blasting of soil and the loss of most of the planted area. Then they were replanted between the end of December and the beginning of January, with the hope of being able to recover productivity rather than harvest “, says the agronomist.
It highlights that there is an important advance of the so-called “hard weeds”, which have a wide distribution. “There are many lots with the presence of Cortadera Chica (Pappophorumsp.), Which is very difficult to control, which in many cases leads the producer to tillage the lot in order to eradicate the weeds. Glyphosate resistant weeds (Eleusine, Sorghum from Aleppo and Cynodon), and other glyphosate tolerant and ALS inhibitors, such as Amaranthuspalmeri “, he describes.
In the Conlara Valley, the preliminary percentages of the area sown per crop are as follows: 60% is occupied by corn, another 30% by soybeans, Graniferous sorghum has 6% and others such as sunflower, confectionery sunflower and pisingallo corn they kept 4%.
Corn
There is a considerable increase in the area sown with this cereal. There was an early sowing (mid-November), with crops that are in a vegetative state, with 8 to 9 leaves (V8-V9).
The later sowing lots (beginning at the end of December) are also passing the vegetative stage, with 2 to 5 leaves (V2-V5). “Most are in good to very good condition, but the most advanced plots in the cycle suffered the effects of hydric stress in December, although they reversed it with the rains at the end of the year,” says Bongiovanni.
Although there is an increase in the surface area, a significant percentage of lots (35-40%) with low technological investment can also be observed, which translates into hybrids with lower potential, hybrid child seeds and little or no fertilization, among other problems. “With the improvement of the water condition, many producers decided to refertilize with nitrogen to ensure a higher yield in those lots that are on the right track,” he adds.
Fortunately, so far no disease has been observed. “Regarding pests, specific attacks of fall armyworm (Spodopterafrugiperda) were detected in 10% of the batches, with slight damage that a priori should not generate losses in yield”.
Soy
The crop registers a significant decrease in sowing intention (15-20%) compared to previous seasons. It is something that also happened in other productive areas and at the national level. “The few lots sown at the end of October, after the first rains, are beginning the reproductive stage (R1). They suffered the consequences of the lack of rainfall in December, developing a lower height, which can affect yield. They are the majority. the lots sown in November (80% of the total) and are in a vegetative state (V5-V7), as well as those in December, which go from V2 to V4. Late sowing lots are the ones with the best condition “, he qualifies the professional.
During December, attacks by defoliating caterpillars (Rachiplusia, Anticarsia, Helicoverpa) were registered in a low percentage of lots (5-10%). In most, the damage was below the thresholds for each species.
Grain sorghum
It is a crop that benefited from the retraction of soybeans. The greater safety of harvest in dry years, good prices in the market and the incorporation of Igrowth technology (tolerance to imidazolinones) in some hybrids, have determined that many producers opted for this cereal, which had not presented a significant surface area for several seasons. . This season, the sowing of grain sorghum doubled the area compared to previous years. “The lots were sown from the beginning of November to the beginning of December. Regarding the phenology, they are in the vegetative stage (V4-V9) and generally present good to very good conditions”, assures Bongiovanni.
Their monitoring detected that sanitary conditions, in general, are very good. “In some specific batches the presence of aphids (Rhopalosiphummaidis) and fall armyworm (Spodopterafrugiperda) has been observed; as regards diseases, the presence of bacteriosis (Stain and Bacterial Stria) stands out but with low incidence”.
In the mountainous area of La Cumbre and La Petra, 220 millimeters fell between December and January, records above the average.
Wheat
“The fine harvest season was very limited. The wheat sowing was limited to fields with sprinkler irrigation, since there were no conditions for the implantation of dry fields, during the autumn of 2020. The harvest was carried out at the end of November in mid-December, yielding good results: 35-40 quintals per hectare. These lots, once harvested, were mostly planted with second-rate soybeans at the end of December “, he says.
Overview of the central region
Another agronomist, Ramiro Goncálvez, moves through two well-defined areas advising producers. One is the one that includes El Amparo, Cuatro Esquina, La Petra and La Cumbre. There, with rainfall between December and January accumulating 200/220 mm, they are above average.
“Soil profiles follow field capacity (CC), that is, full, since the consumption of crops is below the supply of rain,” he reflects.
The corn is in V12 and in very good condition. “We are 10/15 days from flowering, which is the beginning of the critical period, when the yield is defined. The late maize in V6 and also in very good condition. Meanwhile the soybeans transits between V9 and V10, at the beginning of the flowering. The state is good, without presence of plagues and beginning to close the furrow “, informs Goncálvez.
The other work zone is the one that goes from Eleodoro Lobos to Fraga, passing through Comandante Granville. There the precipitations were more scarce: 100/110 mm, with the appearance of hail in Fraga during the last week. They are rains that are close to the annual average.
“Here the corn is between V5 and V7 and in good condition, recovering from 15 days of high temperature and wind. As for soybeans, it is between V5 and V6, in good condition, with several batches that are recovering from the hail suffered in December “, described the advisor, who left some suggestions:” In soybeans that have not closed the furrow, it is necessary to take advantage of applying herbicides, both for weed control and residuals.
Regarding fertilization, we are using loaded profiles to enhance the process in corn, either by applying UAN or taking advantage of the next 10 days of rain to volley urea. “
–
