Revista Brasileira de Agropecuária Sustentável

ADJUSTING THE OPTIMAL ARRANGEMENT OF PLANTS TO MAXIMIZE THE PRODUCTIVITY AND QUALITY OF LINSEED GRAINS

2022-05-19T00:56:41-03:00

Understanding and exploring the productive potential of crops guarantees the economic
return and sustainability of the activity. In addition to genetic improvement and biotechnological events,
crop management practices contribute to the expression of high crop performance. The aim of this work was
to highlight the effects of row spacing and seed densities on the agronomic performance of flaxseed. The
trial was developed in the experimental area of the Regional Institute of Rural Development, which belongs
to the Regional University of the Northwest of the Brazilian State of Rio Grande do Sul. The experimental
design was randomized blocks, and the treatments were structured in factorial scheme three (spacings) x
six (densities) with three replications per treatment, totaling 54 experimental units. We used three spacings
between rows, 18 cm, 36 cm and 54 cm, and densities of 30, 60, 90, 120, 150 and 180 seeds per linear meter.
The experimental units were three meters wide by 10 meters long, totaling 30 square meters. The variables
analyzed are divided into three morphological groups: plant height, height of insertion of the first capsule,
number of branches at the base, stem diameter, number of stem branches, number of productive branches;
productive variables: number of capsules per plant, capsule mass, number of capsules that formed grain,
number of capsules that did not form grains, number of grains per plant, mass of grains per plant, mass of one
thousand grains and grain yield; meteorological variables: rainfall (mm), minimum air temperature (°C) and
maximum air temperature (°C). Grain yield reduces when growing at larger spacings. The highest expression
of grain yield occurs in row spacing of 18 cm. Indirect selection for linseed grain yield can be performed
through the number of stem branches, number of productive branches, number and weight of capsules and
number of grains per plant.

AGRONOMIC PERFORMANCE OF LINSEED AS A FUNCTION OF PLANT ARRANGEMENT

2022-08-04T11:34:20-03:00

The objective of this work was to understand the agronomic performance of flaxseed cultivated in different spacings between rows and plant density, identifying associations between traits for indirect selection. The experiment was carried out in the municipality of Augusto Pestana - RS, in the years 2020 and 2021, using a randomized block experimental design organized in a 6x3x2 three-factor scheme, with six sowing densities (30, 60, 90, 120, 150 and 180 plants per linear meter), three spacings between rows (0.18 m, 0.36 m, .0.54 m), and two crop seasons (2020 and 2021). Ten plants were measured in each plot, having evaluated phenotypic characteristics of plant height, height of insertion of the first capsule, number of basal branches, stem diameter, number of branches on the stem, number of main branches, number of capsules, mass of capsules, number of grains per plant, weight of 100 grains and weight of grains per plant. Grain yield is enhanced in row spacing of 18 cm with densities of 74 seeds per linear meter in crops with favorable conditions. In flaxseed, the number of capsules, number of grains and the mass of grains per plant exhibit a linear association with grain yield and can be used for indirect selection.

PENETROMETERS TO DETERMINE THE RESISTANCE TO PENETRATION IN OXISOL IN PASTURE LAND IN THE CERRADO

2022-04-04T16:23:42-03:00

Soil penetration resistance (PR) is the most common and practical way to estimate the level of soil densification/compaction. The use of PR is evident in most studies, but a large unexplained the different
types of penetrometers capable of quantifying it. Their principle is to measure the soil resistance when is
inserting a cone-tipped rod to a specific depth. This study aimed to compare the use of two penetrometers/
penetrographs to determine the PR of a clayey soil: one static penetrometer (impact) and another dynamic
(digital). For this purpose, three treatments in distinct forage plants were evaluated: i) Cynodon nlemfuensis,
ii) Cynodon dactylon and iii) Cynodon plectostachyus. Soil penetration resistance and soil moisture were
assessed at two depths, i.e., 0–20 cm and 20–40 cm. PR values ranged from 3.0 to 3.9 MPa between the areas,
and soil moisture ranged from 13 to 14%. We found a high correlation between the results of penetrometers
with R2=0,93 and R2=0,95 at 0-20 and 20-40 cm, respect from impact and digital penetrometer. The ANOVA
did not show significant differences (0.05 scored in Tukey test) for the three selected treatments, indicating
similar efficiency of the penetrometers for determining PR values in clayey soil in Cerrado. The methods for
evaluating soil penetration resistance can present equal values through the adjustment equation.

PHYSICOCHEMICAL AND SENSORY CHARACTERISTICS OF ROSÉ SPARKLING WINE PRODUCED WITH MERLOT GRAPES IN “CAMPANHA GAÚCHA”

2022-04-06T18:16:11-03:00

This work evaluated the potential of the Merlot grape produced in Campanha Gaúcha region for the production of sparkling wines. The base wines were made through direct pressing (T1) and cold pre-fermentative maceration (CPM) with 6 (T2), 24 (T3) and 48 (T4) hours of duration. Afterwards, the second fermentation of treatments was conducted by the Champenoise method. The results obtained in the physicochemical analysis demonstrate the potential of elaborating sparkling wines with higher alcohol content from this cultivar in the region. In the sensory analysis, all sparkling wines received excellent scores for overall quality and the best results, in general, were observed in the sparkling wine made with 24 hours of CPM (T3). From the results obtained, we can suggest the Merlot grape as an alternative for the production of sparkling wines in the region, requiring more in-depth studies on maturation time and typology of the
product to be prepared.

DRY MATTER AND PROTEIN ACCUMULATION AS A FUNCTION OF NITROGEN FERTILIZATION IN Brachiaria brizantha CV. MARANDU (Urochloa brizantha)

2022-04-12T00:24:08-03:00

In Brazil, forage is the main source of nutrients for ruminants, but most production systems are extensive and low amounts of inputs are used to improve soil fertility. This study aimed to evaluate the effect of nitrogen doses on dry matter yield and protein content in leaves, stems and shoots of Brachiaria brizantha cv. Marandu. The soil was fertilized with dolomitic limestone and gypsum to raise base saturation to 60% in the 0-20 cm layer and decrease exchangeable aluminum in the subsurface layer. The experimental
design was the randomized blocks with four replications, and the plots were five meters long by five meters wide. Nitrogen fertilization doses were 0 (control), 50, 100, 150, 200 and 250 kg of N ha-1, and applied on the soil surface at the beginning of the regrowth period. Phosphate and potassium fertilization of 50 kg P ha-1 and 150 kg K ha-1 were also carried out. Plants were cut thirty-seven days after fertilization. The evaluations were carried out in the central 9.0 m2 of the plot. A positive effect of nitrogen fertilization was found on all the variables assessed in the study. The effect was linear for fresh matter and dry matter accumulation in leaves + stems of Brachiaria brizantha cv. Marandu. The accumulation of dry matter in leaves + stems was 4.46 t ha-1 in the control treatment, increasing to 6.03 t ha-1 at the highest nitrogen dose. Nitrogen fertilization positively influenced the percentage accumulation of dry matter in leaves of Brachiaria brizantha cv. Marandu, achieving the equation Y= 25.529 + 0.0372x. Consequently, there was a percentage reduction in the dry matter allocated in stems. At the highest nitrogen dose, the percentage increase of dry matter in leaves was 17%. The
effect of nitrogen fertilization on protein content in leaves, stems and leaves + stems was also found. At the highest nitrogen dose (250 kg of N ha-1), there was an increase in protein per kg of dry matter of 86.78 g, as content in the control treatment was 67.5 g kg-1, increasing to 154.3 g kg-1. In addition to increasing the yield due to dry matter accumulation in the plant and improving the bromatological quality, nitrogen fertilization also increased protein production. We should also note that there was an increase in yield and protein production per hectare with the highest dose of nitrogen fertilization.

RE-ENSILING AND MICROBIAL INOCULANT USE EFFECTS ON THE QUALITY OF MAIZE SILAGES EXPOSED TO AIR

2022-04-12T00:39:20-03:00

Re-ensiling has increased worldwide due to the increase in marketing of silage between farms. However, litlle is known about the aerobic deterioration and microbial inoculants effect in this process. The aim of this study was to determine the re-ensiling and microbial inoculant use effects on the maize silage quality. Experimental treatments included maize silage exposed to air for zero or 18 h, with or without microbial inoculant use containing a mixture of Lactobacillus plantarum and Propionibacterium acidipropionici. The forage was ensiled in 20 plastic buckets (20 liters capacity) with five repetitions per treatment. The silos were opened after 116 days and the chemical composition, in vitro dry matter digestibility (IVDMD), fermentative parameters, microorganism counts, total dry matter (DM) losses and aerobic stability of silage were evaluated. Re-ensiling reduced the non-fibrous carbohydrates content by 13.0%. The IVDMD was reduced by 6.1% in re-ensiled silages. In addition, re-ensiling increased the losses due to gases, effluents, and total DM. Lower lactic acid content and higher acetic acid content in re-ensiled maize silages were also observed. However, IVDMD increased by 4.96% in inoculated silages. Re-ensiling reduces the nutritive value and IVDMD of maize silages and should be avoided in production systems. The microbial inoculant use is not effective in improving the re-ensiled silage quality, which does not justify its use in these conditions. Farms should avoid purchasing maize silage due to reduction in nutritional value in the re-ensiling process.
However, in some cases where farms need to purchase silage for feeding planning, the time between silo opening and re-ensiling should be as short as possible to reduce nutrient loss. Furthermore, in this situation the inoculant use does not improve silage conservation, which makes its use unnecessary.