Custos energéticos do agroecossistema pinhão-manso e milho: comparativo entre o sistema de condução sequeiro e o irrigado

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito de dois sistemas de manejo do solo nas propriedades físico-hídricas, desenvolvimento radicular e produtividade do milho

Corn cultivation is part of crop rotation used by irrigation farmers from the southwestern region of São Paulo state, Brazil, who use no-tillage soil management as a kind of sustainable use of soil. The effect of this conservative practice on physical and hydrical properties of the soil, root development and corn crop yield compared to the conventional management was the objective of this work. The experiment was held at the Buriti-Mirim Farm, Angatuba, SP, Brazil, using an irrigated area with a center pivot system and two types of soil management: conventional and no-tillage systems. Although the no-tillage management had higher soil density and less water availability, no significant difference was found for both management systems concerning soil resistance to penetration, root development and crop yield. In both systems of soil management, 90% of roots were concentrated in the first 0-20cm of soil layer.

Métodos de determinação da densidade do solo em diferentes sistemas de manejo

Soil bulk density is an attribute often used to characterize soil physical structure, being an indicator of soil compaction. The objective of this study was to compare the values ​​of bulk density measured by the paraffin sealed clod and volumetric ring methods in conventional, no-tillage and minimum tillage systems on a Dystroferric Red Nitosol, clayey, in Botucatu, SP. The experiment design was a 3x2 factorial arrangement in randomized block with four replications. The density values ​​obtained by the paraffin sealed clod method were statistically higher than those obtained by the volumetric ring method. There was no difference between the managements when comparing the values ​​of soil density obtained by the paraffin sealed clod method. The soil under conventional management showed lower density when comparing the values ​​of soil density obtained by the volumetric ring. The volumetric ring method was more sensitive to show differences between the management systems than the paraffin sealed clod method.

Características agronômicas e demanda energética de cultivares de soja sob efeito dos sistemas de preparo do solo

The aim of this study was to evaluate the influence of preparation: intermediate grade, minimum tillage and no-till on the agronomic characteristics and energy demand of transgenic soybean cultivars and non-GMO soybeans. Soil preparation aims at improving physical, chemical and biological conditions, aiming at good emergence and plant development. The different types of tillage may interfere with the agronomic characteristics and productivity of plants, and in energy use which can cause variation in production costs. Genetically modified plants can be one of the alternatives for reduction of production costs in crops by reducing pesticide applications, enabling higher productivity with less environmental impact. The test was conducted in 2010/2011 at the agricultural Experimental Farm Lageado, belonging to the Faculty of Agronomic Sciences – UNESP, located in the city of Botucatu, SP in an area using no-till systems for the past 12 years. The experiment was carried out in a 3 x 2 factorial, randomized treatments were comprised of three soil preparation systems, minimum cultivation, intermediate grade preparation and no-till, with two cultivars of soybeans: MGBR-46 Conquest (conventional), Valuable RR (Transgenic). The data obtained was submitted to variance analysis using Tukey test at a 5% probability. With the results analyzed it might be observed that there was no significant difference between treatments, in the variables, the percentage of soil cover, final soybean plant population, grain yield and plant height. The results obtained show that the no-till system resulted in higher productivity than conventional tillage and minimum cultivation. The higher specific energy use per area was observed in minimum cultivation with a chisel plough, when compared to the preparation across the grid. The greatest fuel consumption was to treat minimum cultivation with chisel plough. The highest values were found in the skating system of minimum cultivation, being greater in conventional tillage system. It is more satisfactory for the producer to sow transgenic soy using a no-till system, because productivity retrieved from that system compensates for fuel expenditure.

Demanda energética em diferentes manejos de solo e híbridos de milho

This study aimed to account the energy balance of six different farming systems: CMT (minimum tillage with transgenic corn); CMNT (minimum tillage with non-transgenic corn); PCT (conventional tillage with transgenic corn); PCNT (conventional tillage with non-transgenic corn); PDT (no-tillage system with transgenic corn) and PDNT (no-tillage system with non-transgenic corn). The study was carried out at the Experimental Farm Lageado FCA/Unesp, Botucatu - SP. The energy balance was performed by subtracting the total energy inputs by the total energy output. Energy efficiency was calculated by dividing the total energy output by the total energy inputs. The total values ​​of energy inputs and outputs were expressed in MJ.ha-1 (mega joules per hectare). To calculate the energy inputs were accounted the fuel consumption and lubricants, depreciation energy of machinery and implements, manpower and agricultural inputs. The energy outputs were calculated according to the maize yield. The result shows that the system PDT was the system that had better energy efficiency and the system that had the lowest efficiency was the PCT system. The system with lower energy demand was the PDT and the greatest demand was PCNT.

Atividade da enzima nitrato redutase em cultivares de arroz de terras altas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Parcelamento de fontes alternativas de nitrogênio no milho safrinha em sucessão à soja

Increasing out-of-season corn productivity is possible by the application of nitrogen fertilizers even when in succession to soybean. On the other hand, information concerning the best sources of nitrogen and ways of splitting the doses to be applied is still scarce. Having that in mind, an experiment was carried out viewing to evaluate the effects of sources of nitrogen and ways of splitting doses of those N fertilizers on out-of-season corn sown in succession to soybean cultivated in a no-tillage system. The experiment took place in Chapadão do Céu, state of Goiás, Brasil (latitude of 18°35’42’’ South, longitude of 52°47’59’’ West and mean altitude above sea level of 802 m) in an Acrutox. The experimental units were distributed in the field in accordance with a randomized complete block design, in a factorial scheme 3 X 5 + 1, with four replications. Three were the sources of N: urea, urea extruded with starch (Amireia®) and ammonium sulfonitrate with a nitrification inhibitor (Entec®) and five the ways of splitting the nitrogen dose : 90-0, 60-30, 45-45, 30-60, and 0-90 in which the first fraction was applied at sowing and the second in side dressing. In addition to those, there was a check treatment, without N. All plots received, at sowing, 12 kg ha-1 of N by the mixture NPK. The ways of splitting the N dose and the sources of N had no significant effect on the levels of N and S in the leaves, first ear height, the final plant population, the number of ears per plant, and the number of grains per ear. N in the Entec® form at the highest doses applied in side dressing resulted in the highest grain yield, independently of the way the N dose was split. Only in the form Entec® the dose of 90 kg ha-1 of N increased grain productivity by 9.6% in comparison with the check treatment.

Efeito de diferentes herbicidas, doses e volume de calda na dessecação de milheto [Pennisetum glaucum (L. Leek)]

The objective of this work was to evaluate the efficacy of different herbicides applied in post-emergence in the desiccation of pearl millet with different doses and spray volumes. For the desiccation, doses at 0, 25, 50 and 100% of the herbicide glyphosate (1,440 g ha-1) were used in 3 formulations (Original Round up, Round up Transorb and Round up WG), paraquat + diuron (500 + 250 g ha-1) and glufosinateammonium (800 g ha-1). In all treatments, 2 spray volumes (200 and 400 l ha-1) were used, and there was 1 treatment (control) without the application of herbicides. The treatment effects were evaluated visually at 3, 7, 14, 21 and 28 days after application (DAA). At the end of the evaluations, the dry mass of the plants was determined. The field trial was carried out in randomized block design. At the end of the study, at 28 DAA, all treatments presented total control of plant pearl millet, regardless of the dose and spray volume, except the treatments with paraquat + diuron and glufosinate-ammonium at the lower dose (25%), in 2 spray volumes, which nevertheless showed good and very good control, these two herbicides presenting an effect of volume, in which the control was higher with the use of smaller volume.

Consórcio de milho e Urochloa ruziziensis e inoculação com Azospirillum brasilense e seu efeito residual associado à adubação nitrogenada em feijoeiro de inverno

Pós-graduação em Agronomia - FEIS

Avaliação dos modelos de predição da erosão hídrica MEUPS e WEPP: contribuição em bacias hidrográficas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Produção e qualidade de silagens de sorgo em sistema de integração lavoura-pecuária no cerrado de baixa altitude

Pós-graduação em Agronomia - FEIS

Qualidade física e química do solo em função do sistema de produção e da aplicação superficial de silicato e calcário em experimento de longa duração

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Doses e modos de aplicação de Boro e adubação com Zinco na cultura do milho

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Plantas de cobertura, adubação nitrogenada e produção de sementes de feijoeiro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Eficiência e seletividade dos herbicidas trifloxysulfuron-sodium + ametryne e hexazinone + diuron em função da tecnologia de aplicação e do manejo mecânico da palha de cana-de-açúcar na linha de plantio

Com objetivo de otimizar a utilização de trifloxysulfuron-sodium + ametryne e hexazinone + diuron em função da adoção de diferentes pontas de pulverização e manejo mecânico da palha de cana-de-açúcar na linha de plantio, dois experimentos foram conduzidos na Destilaria Parálcool S/A, localizada em Paraguaçu Paulista/SP. No experimento 1, 12 tratamentos foram estudados em esquema fatorial 2 x 2 x 3, com quatro repetições, contrastando a presença e ausência de palha da cana na linha de plantio; dos herbicidas trifloxysulfuron sodium + ametryne (37 + 1.463 g i.a. ha-1 e 0,2% v/v de Aterbane®) e hexazinone + diuron (330 + 1.170 g i.a. ha-1 e 0,2% v/v de Aterbane®) e das pontas de pulverização XR11002-VS (128 L ha-1), AI11002-VS (200 L ha-1) e TF-VP5 (310 L ha-1). No experimento 2, a deposição da calda de pulverização nas plantas de cana-de-açúcar e Digitaria horizontalis, gerada pelas interações entre herbicidas e pontas, foi monitorada utilizando-se solução traçadora constituída por corante FDC-1 + herbicida. Os resultados sugerem que a presença da palhada da cultura proporcionou controle excelente das espécies infestantes mesmo na ausência do tratamento herbicida. O controle químico de D. horizontalis (6 folhas até 1-2 perfilhos) e Brachiaria decumbens (2 a 6 folhas) apresentou-se eficiente (> 91%) nas linhas sem palha a partir dos 14 DAA (dias após aplicação) para os herbicidas e pontas de pulverização estudados. D. horizontalis foi mais rapidamente controlada aos 7 DAA pelo trifloxysulfuron-sodium + ametryne com a ponta AI11002-VS. Houve toxicidade até os 21 DAA, sendo esta mais intensa para os tratamentos com hexazinone + diuron associado com as pontas AI11002-VS e TF-VP5, em decorrência da maior deposição do herbicida nas folhas da cultura.