The application of liquid swine manure (LSM) in the soil as biofertilizer is one of the most recycling alternatives adopted, because the nutrients contained in this residue can override, in part or totally, commercial fertilizers, crop productivity with a reduction in production costs. The goal with this work was to evaluate the use of LSM as a substitute of mineral fertilization on soybean culture in conditions of Savannah in 2014/2015. The experimental design was of randomized blocks with three replications. The treatments consisted of the use of mineral fertilizer recommended for soybean culture; without fertilization; and doses of LSM (25; 50; 75 and 100 m³ ha -1 ). The levels of N, P, K, Ca, Mg, Cu, Zn, Mn and Fe in leaves, seeds and dry matter from the shoot, plant height and productivity of grain was assessed. There was no statistical difference between treatments that received mineral fertilization (P and K) and the treatments that received pig manure, indicating that the use of pig waste as bio fertilizer on soybean fertilization may be a promising alternative. The mineral fertilizer in soybean culture can be replaced by shots of LSM from 80 m³ ha -1 with no losses in grain productivity in a clayey dystroferric Red Latosol. The applications of doses of pig manure generally did not promote increase in the content of nutrients in grains and in the extraction of nutrients by the aerial part of the soybeans plants.

Crop yield decrease is the main concern when a pathogen or plague is identified in an agriculture field. Thus, part of this issue can be attributed to plant-parasitic nematodes (PPNs), such as Meloidogyne species, due to, most of the time, the hard diagnosis, and non-specific symptoms. Its management is mainly based on chemical pesticides, followed by a few potential biological control agents, and the management system. Therefore, this study aimed to evaluate the effects of biological agents in Meloidogyne incognita control in different soil systems. For that, two biological products were chosen, Trichoderma asperellum BV10 and Bacillus amyloliquefaciens BV03, and soils were sampled from three different managements systems: (i) soybean no-tilled system at Goiás state, Brazil; (ii) forest soil at Goiás state, Brazil, and (iii) soybean conventional managed system at Mato Grosso do Sul state, Brazil. Biocontrol and growth promotion effects, volatile organic compounds (VOCs) and soil respiration were determined in vegetation house and laboratory, respectively. As a result, both BV10 and BV03 had significant nematode control activity, comparing to control treatment, in all the three soils systems. Plus, the number of immobile nematodes by potential VOCs had significant increase when BV03 was applied, while the application of BV10 agent raised the soil respiration rate. In conclusion, both biocontrol agents presented great efficiency in control M. incognita, with better performance of BV03. Lastly, more studies must be done to elucidate how the resident soil microbiome can influence on biocontrol agent establishment and performance, as well as the consequence of the application of biological products on soil microbiome network.

Knowledge of the solubility of phosphate fertilizers is fundamental for phosphorus (P) recommendation management and for choosing the laboratory evaluation method of nutrient availability in the soil according to the history of fertilization. The aim was to evaluate the initial development of corn plants as a function of the application of triple superphosphate (TSP) and natural phosphate of Arraias (NPA) with and without liming and incubation time, as well as to evaluate the available P in the soil with the use the extractors Mehlich-1 and Mehlich-3. An experiment was installed in an 8 × 3 × 2 factorial scheme, being 8 fertilizer incubation times (180, 140, 100, 80, 60, 40, 20, 0 day(s) before planting), 3 P sources (control—without P, TSP and NPA) and 2 refers to the application of limestone (with and without limestone). Were evaluated the shoot and root dry matter, analysis of P, Ca, Mg, and Zn in shoot and P in roots. In the soil, P levels were determined by Mehlich-1 and Mehlich-3 extractors. There was a greater accumulation of P with the application of TSP with limestone in all incubation times. The application of the NPA allowed a greater accumulation of P in the plants without the application of lime. The previous incubation of the NPA did not favor the efficiency of this source, neither in the soil with corrected acidity nor in the soil with its original acidity. Mehlich-3 proved to be adequate to determine the phosphorus content in soil fertilized by NPA.

Biostimulants are used as a strategy to minimize the effects of climatic adversities by allowing the seedlings to express more strongly their metabolic capacity and to have a greater root system development. The objective was to evaluate the effect of seed treatment with different doses of a biostimulant composed of Ascophyllum nodosum on the agronomic performance of maize seedlings. The experiment was carried out in a randomized block design with five treatments and four replicates, using five doses of the biostimulant, 0,0; 0.25; 0.50; 0.75; and 1.00 liter of product per 100 kg of seeds. The following were evaluated: vigor, fresh mass of roots and shoots, dry mass of roots and shoots, root length, shoot height, and leaf area. The data were submitted to ANOVA and regression analysis to verify the behavior of the characteristics as a function of the biostimulant doses. In the treatment of seeds, these doses provided increases in vigor, shoot height, fresh and dry mass of shoots, and leaf area. The biostimulant derived from the Ascophyllum nodosum extract showed potential use in the treatment of maize seeds, with the doses of 0.50 and 0.75 liters per 100 kg seeds being the most promising for the initial development of maize seedlings.

Fertilization management is one of the agricultural practices that demand high investment. Thus, the objective was to evaluate the economic viability of using combinations of fertilizers applied to soybean and corn cultivated in succession in Goiás Savanna soil. The experiment was carried out in the field, in randomized blocks. The fertilization management consisted of the combination of monoammonium phosphate fertilizers; urea; 08:40:00 +9.3%S and 3.2% Ca; simple superphosphate; potassium chloride; elemental sulfur; polyhalite (37% K2O + 9.2% S, 5.8% Ca and 1.7% Mg) and polyhalite S (14% K2O + 19.2% S, 12% Ca and 3.6% Mg) which were applied in soybean sowing and evaluated the residual effect on corn. The economic assessment took into account crop productivity and fertilizer prices in the 2018/2019 agricultural year. For each treatment, the operating cost (COi) and profitability indicators were calculated: gross revenue (GRi); net revenue (NRi); profitability index (PITi); equilibrium production (Yei) and equilibrium price (Pei). Crop productivity was not influenced by fertilizer management, showing that economic indicators can help producers choose the management with the best return and that adjusts to the financial situation of the rural company. Thus, it is concluded that the management of MAP + KCl fertilization was economically outstanding in soybean cultivation and the MAP/S + KCl applied to soybeans, associated with nitrogen fertilization in corn coverage was the most viable for off-season corn. The economic indicators showed that the MAP+KCl fertilization performed on soybean, associated with urea in corn coverage, is the most viable management system for the soybean-corn production system cultivated in succession.

No abstract

No abstract

The soils of Brazilian Savanna, naturally, present acidity problems, making correction practices fundamental to ensure production. Even with so many years since the introduction of agriculture, some soil correction practices are still misused. Thus, the objective was to evaluate soybean yield and chemical changes in a Red Oxisol in the Brazilian Savanna with the use of limestone, associated or not with gypsum, applied superficially and incorporated by harrow and moldboard plow. The experiment was conducted under field conditions, in Rio Verde-GO, cultivating soybeans in the 2015/2016 and 2016/1017 harvests. The experimental design was in randomized blocks, with four replications, with treatments arranged in a 3 × 3 factorial scheme. The first factor refers to the application of superficial limestone and incorporated by harrow and moldboard plow. The second factor was the presence or absence of limestone and/or gypsum (0 + 0; 0.875 + 0 and 0.875 + 1.75 t ha-1). Plant height, number of pods per plant, productivity, pH, Al, CTC, Ca, Mg and V were evaluated, in soil depths of 0-0.2 and 0.2-0.4 m. In the 2016/2017 harvest, the characteristics of pH, CTC, V and contents of Ca, Mg and Al were influenced by the methods of application of limestone and by its use, associated or not with gypsum. There was an increase in pH on the soil surface with the use of limestone and on the subsurface with the use of limestone and gypsum. The moldboard plow provided increases in the contents of Ca and Mg in the soil in comparison to surface application. The moldboard plow incresed in soybean yield, in the second crop, with and without association of gypsum with limestone.