No abstract

The system of intercropping maize with other plant species has been a common practice for several years, but its use has been increasingly mainly to improve the quality of soil physical properties of notillage system. The objective of this study was to investigate the effect of intercropping using different cover plants on the physical properties of soil and the productivity of maize. Field experiments were conducted on the property of Mr. Arno Paulo Deimling, located in Linha São João, in the municipality of Quatro Pontes-PR. The experiment was carried out using a randomized complete block design, with four treatments and five repetitions. The treatments were winter maize intercropped with Urochloa brizantha, Urochloa ruziziensis or black oats (Avena strigosa), and maize sown in monoculture. In winter period, the production of maize used for silage and the production of dry matter from cover crops were assessed. The physical properties of soil samples were also investigated. Cover crops did not influence the productivity of winter maize used for silage, but it promoted improvements in soil macroporosity. The cover crops promoted improvements in the macroporosity of the soil and reduction at soil penetration resistance, particularly in the area planted with U. brisantha, demonstrating its potential in improving water infiltration and soil aeration.

The objective of this work was to evaluate the carbon content of the physical, chemical and oxidizable fractions of soil organic matter (SOM) and to calculate the carbon management index (CMI) in an area managed under an integrated crop-livestock system (ICLS) in the western region of Paraná - Brazil. The experiment was carried out at the experimental farm, belonging to the Universidade Estadual do Oeste do Paraná. Seventeen areas, which are managed in different ways, fifteen in ICLS and two areas of controls (Forest and Haymaking), using the design divided with two nested controls, with three replications were evaluated. Deformed and undisturbed soil samples were collected from all the areas to determine the total organic carbon (TOC), carbon stock, the physical, chemical and oxidizable fractions of SOM and the CMI in the layers of 0-0.05, 0.05-0.1 and 0.1-0.2 m. Little significant changes in the fractions were found for the management of the ICLS area in relation to the Forest and the area of Haymaking, although the Forest presented the best values for most of the studied fractions. It is recommended to adopt sustainable practices, such as ICLS, even though the average fractions tend to take time to match reference areas.

The objective of the work was to evaluate the structural characteristics of black oats, forage production and remaining dry matter, conducted in a crop-livestock integration system. The treatments consisted of two black oat sowing densities (40 and 60 kg ha-1 of seeds) and crop management: no grazing, one grazing and two grazing. Plant height, number of tillers, stem diameter, stem leaf ratio and available and remaining dry matter productivity were evaluated. The available dry matter productivity was higher for the management without grazing, as well as the remaining dry matter productivity, for the first and second sampling. For the second sampling, the height of plants was greater where grazing did not occur, however, the largest number of tillers was greater for oats once grazed.

No abstract

Soil organic matter is degraded and easily altered by the type of management. The objective of this work is to determine the total organic carbon and humic substance fractions in the organic matter of the soil with different management types and depths in the western region of Paraná, Brazil. The work was carried out in the Experimental Farm "Professor Antônio Carlos dos Santos Pessoa", belonging to the State University of the West of Paraná. Five soil management systems were evaluated: one area with corn cultivation for silage (CS); other area with succession of crops, with soybean in summer and corn in winter (SC); the next area also with succession of crops, with soy in the summer and oat in the winter (SO); the following area with permanent pasture with Tifton (PP); and the last area with crop-livestock integration (ILC). For each management system, four plots were randomly selected, in each plot three simple samples were collected in a diagonal direction to form a composite sample for the depth of 0.00-0.05 m, 0.05-0.10 m and 0.10-0.15 m. Total organic carbon, fractionation of the humic substances and the AH/AF and EA/HUM ratios were calculated. For most of the analyzed variables, it was verified that there were significant differences (P < 0.05) between the systems evaluated in the studied depths. In the evaluated areas, the PP, SO and ILC systems presented the highest carbon content for all attributes analyzed.

No Brasil são semeadas duas safras de milho por ano, fator que contribui para o aumento da incidência e severidade de doenças fúngicas, que refletem em significativas perdas do potencial produtivo da cultura. O objetivo desse trabalho foi avaliar a aplicação de fungicida em híbridos de milho em diferentes estádios fenológicos. O delineamento foi em blocos casualizados com quatro repetições, num esquema fatorial 5 x 2 x 3, sendo cinco híbridos (DG213, Formula TL, CD308, P30K64 e Formula VIP), com e sem azoxistrobina + ciproconazol e água em três estádios fenológicos (V8, VT e R1). As doenças incidentes foram ferrugem polissora, mancha branca e cercosporiose. O uso do fungicida proporcionou maior sanidade às plantas e um aumento médio de 5, 11 e 14% no diâmetro de colmo, massa de mil grãos e massa de espigas, respectivamente. A aplicação em R1 não afetou a viabilidade de grãos de pólen. Os híbridos P30K64 e Formula VIP produziram 31 e 18% a mais, respectivamente. Nos híbridos Formula TL e CD308 o aumento médio na produtividade foi de 17%. Não houve interação para produtividade do DG213 um hibrido duplo precoce. Independente do híbrido, o fungicida em V8, VT, e R1 aumentou em média 18, 30 e 21% a produtividade, caracterizando o pendoamento como a melhor época de aplicação.

The objective was to evaluate the decomposition and nutrient release of biomass from maintenance of fallow or oat crop (IPR 126), managed in integrated crop-livestock, during the soybean crop cycle (85 days) in no tillage system in two years (2014 and 2015). The design was a randomized complete block in a subdivided plot scheme, with the parcel consisting of four plots (four straws, from fallow or oat cultivation) and the subplots (evaluation periods 0, 10, 35, 60 and 85 DAS) with the evaluation times throughout the crop cultivation soybean. The amount of biomass and the content of C, N, P, K, Ca, Mg and Zn were calculated. The amount of biomass and nutrients presents a similar pattern of decrease in their values; however, the climatic conditions and the C/N ratio play an important role in the decomposition and mineralization of nutrients. The mineralized amount of N, K, P, Ca, Mg and Zn is directly proportional to their initial content in the biomass, and K nutrient is quickly released from crop residues. Most of the nutrients studied were released during the soybean crop development cycle, favoring its development; this can provide a reduction of external inputs in the property.