Recommended dose of biological fertilizer guarantees multifunctional results in soybeans

The sustainability of agribusiness begins “within the gate” through adequate soil management. To achieve this, it is necessary to build balanced fertility taking into account the integration of chemical, physical and biological factors of the soil-plant system. The rational use of inputs becomes extremely important to achieve the desired productivity.

 Nutritional and physical soil management practices are widespread among farmers. The most current discovery and growing knowledge are bioinputs. Based on this, an experiment was developed on the property located in the municipality of Palmeira das Missões/RS, with the objective of evaluating the contribution of the so-called “foliar” application of Microgeo Biotechnology, in soybean cultivation.

The Biological Fertilizer produced with Microgeo aims to reestablish the soil microbiome regardless of the crop. By restoring the biodiversity of microorganisms in the agricultural system, each microorganism will perform its function promoting multifunctional results in farming, such as: physical biostructuring of the soil, greater nutritional efficiency, ecological health of the soil and plants and, consequently, greater productivity.

To obtain the benefits, Microgeo recommends applying a dose of 150 or 300 L/ha called “soil” (depending on the crop) and doses of up to 5% (volume spray) called “foliar”. Application suggestions for grain crops are shown in Table 1. 

While application via “soil” becomes fundamental to achieve the results of physical biostructuring of the soil and greater efficiency of fertilizers, application via “foliar” leads to greater plant health. Therefore, the application routes are not optional, but rather complementary to achieve the maximum benefits provided by microorganisms from biological fertilizers.

The experiment was carried out in the off-season soybean crop during 2016, with the second harvest being treated with Microgeo Biotechnology (corn was implemented in the summer harvest). The treatments were: T0 – Control (Biological Fertilizer via soil); T1 – Biological Fertilizer via soil and 2 applications via foliar in pre-flowering; T2 – Biological Fertilizer via soil and 3 applications via foliar post-flowering; T3 – Biological Fertilizer via soil and 5 applications via foliar, 2 in pre-flowering and 3 in post-flowering.

The application of biological fertilizer produced with Microgeo via soil occurred at a dose of 150 L/ha at the time of post-emergence of the crop, as recommended (described as Option 1 in Table 1). And the foliar application dose was 5% of the syrup volume, following the application times according to the treatments. The other inputs used and their respective costs are listed in Table 2 (values ​​referring to the year of the experiment). It is noteworthy that no mineral fertilizer was used for soybean cultivation.

Given the multifunctionality of biological fertilization, resistance to soil penetration was evaluated as a means of measuring physical soil compaction (Falker model penetrameter), attack of plants by pests, depth of the root system, productivity and gain study. financial. 

Results

Before installing the experiment and after harvesting, the soil's resistance to penetration was measured. The results are shown in Graphs 1, 2, 3 and 4, which are presented superimposed on the evaluation in each evaluated period, according to the area of ​​each treatment, in order to compare the evolution of soil compaction. Treatment T0 totaled 48.721 KPa, 4,8% lower than the assessment carried out at the beginning of the experiment. Treatment T1 totaled 50.535 KPa, 1,3% lower than the first evaluation. The T2 treatment totaled 43.842 KPa, 14,3% lower than the first evaluation. Unlike the other treatments, T3 totaled the highest value (56.570 KPa) and achieved an increase in soil compaction of 10,5% compared to the measurement carried out at the beginning of the experiment.  

The evaluation of the depth of the root system (Table 3) showed no differences between treatments, however, the T2 treatment obtained a greater average root depth, reaching 14,5 cm, being 12% greater than the control that obtained the lowest value. The lower soil compaction was precisely accounted for in the T2 treatment, and can be considered one of the variables that influenced the non-impediment of root development when compared to the other areas. 

During the crop cycle, trefoils attacked by diseases were periodically counted. It was diagnosed that the disease that most attacked the crop was Asian Rust (Phakopsora pachyrhizie). According to the results (Table 4), it appears that treatment T3 had a lower rate of disease infestation compared to the others, but did not differ statistically from T1 and T2. Treatment T0 was the one with the highest rate of attacked trefoils, with a difference of 15,4%, 20,5% and 28,3% respectively to T1, T2 and T3. This proves the importance of foliar application of Microgeo Biotechnology. As the T0 treatment did not receive “foliar” applications throughout its development, the plant was not induced to resist, making it more vulnerable to pest attack and disease development. Please note that there is no need to apply more frequently than 4 applications throughout the cultivation cycle. 

The soybean productivity results (Table 5) do not differ from each other. However, the T2 treatment was the one that obtained the highest productivity (2538,86 kg/ha), with an average gain of 3,3 sc/ha more than the T0 treatment, which obtained the lowest productivity (2338,72 kg/ha). there is).

Finally, the net yields of each treatment were evaluated according to the inputs used (Table 6). The highest profitability was observed in the T2 treatment, with a total of R$ 2.560,00 per hectare.

In general, the trend in results demonstrates the synergy of the integration of production factors benefiting soybean cultivation promoted by biological fertilization. In treatment T2, the appropriate management recommendation from Microgeo Biotechnology, consisting of “soil” and “foliar” applications, resulted in: less soil compaction; in better root development; positively influenced the induction of plant resistance, reducing the attack of pests and diseases; It is noteworthy that the soybean crop did not receive mineral fertilizers, therefore the biological fertilizer helped with greater nutritional efficiency; consequently, productivity as well as profitability were the highest achieved. 

André Signori and Maria Stefania Cruanhes D´Andréa-Kühl, experts at Microgeo