Ecophysiology and water use efficiency of soybean cultivars under field conditions

A wide range of soybean cultivars is available on the market and understanding the physiological response and yield of these materials is fundamental to develop new management systems. Thus, the objective of the present study was to assess ecophysiological parameters and yield of soybean cultivars under field conditions. The experiment was carried out on a farm located in the municipality of Açailândia, Maranhão, Brazil. Three commercial cultivars were used (SC1, SC2 and SC3), and gas exchanges, SPAD index, Fv/Fm, photosynthesis index (PI), instantaneous water use efficiency (WUE) and intrinsic instantaneous of the use of water (iWUE) were assessed during the vegetative (V5) and reproductive (R5) stages. In addition, the biomass and production components were obtained. A randomized complete block design was used, with three cultivars and six replications. SC2 obtained the best mean for the photochemical variables. SC2 was more efficient at both development stages in WUE, but the maximum iWUE values were obtained in SC3. The SC2 cultivar obtained the best responses in the main variables analyzed, resulting in a higher yield.

Uniformity of water distribution by a sprinkler irrigation system on a soccer field

Soccer field grass can be compared to highly sensitive crops regarding water deficit and must be irrigated throughout the year to provide decent conditions for use. For this, efficient irrigation systems are necessary to save water and energy, and this is possible, provided that they are evaluated. Therefore, this paper evaluated the water distribution uniformity, by different methodologies, for an irrigation system installed in a grass soccer field. Also, the influences of multiple spacings between sprinklers and meteorological factors on the final results were assessed. The irrigation system had Falcon 6504 sprinklers, operating at the pressure of 320 kPa. Six field essays were conducted considering overlaying water depths originated from the same irrigation system considering spacings between sprinklers varying from 6 m x 6 m, 6 m x 9 m, 9 m x 9 m, 9 m x 12 m, 12 m x 12 m, 12 m x 15 m, 15 m x 15 m, 15 m x 18 m, 18 m x 18 m, 18 m x 21 m, 21 m x 21 m, 21 m x 24 m, 24 m x 24 m, 24 m x 27 m, 27 m x 27 m, 27 m x 30 m and 30 m x 30 m. The uniformity coefficients used were: Christiansen uniformity coefficient (CU), distribution uniformity coefficient (DU), absolute uniformity coefficient (UA), statistical uniformity coefficient (US), Hart uniformity coefficient (UH) and HSPA standard efficiency (UHSPA). Meteorological data were obtained during the essays. Wind speed caused reduction in the length of the water jet applied by the sprinkler and also caused a bigger effect on the water distribution uniformity. Both CU and UH showed higher values compared to the other coefficients. The increase in the spacing between the sprinklers resulted in reduced water distribution coefficients. To comply with technical and economic criteria, an arrangement of 12 m x 15 m between the Falcon 6504 sprinklers, operating at a 320 kPa pressure, is recommended.

Atmospheric evaporative demand and water deficit on the ecophysiology of Rubber seedlings

The search for genetic materials resistant to adverse weather conditions has been a major focus in studies on species of economic interest. The objective of the present study was to assess the growth and photosynthesis of rubber seedlings clones under two conditions of atmospheric evaporative demand, characterized by fluctuations in temperature (TEMP) and vapor pressure deficit (VPD), associated to two water regimens. Hevea brasiliensis Muell. Arg (RRIM 600 and FX 3864) clones were assessed in two microclimates, at low (TEMP 21.2 ºC and VPD 0.29 Kpa) and high (TEMP 26.9 ºC and VPD 1.49 Kpa) atmospheric evaporative demand, under two water regimens: water deficit and well-watered. Water deficit 50% water availability was sufficient to reduce the net CO2 assimilation rate, leaf area and total chlorophyll of the clones studied that impacted growth in both microclimates. The effects of water deficit on growth and net carbon assimilation rate were intensified under high atmospheric evaporative demand. However, when comparing the two clones studied, RRIM 600 showed greater growth and photosynthesis without water restriction. The FX 3864 clone, despite the high CO2 assimilation values under high atmospheric demand and without water restriction, showed a reduced growth. The results of this study form an important basis for the selection of genotypes with the potential to develop in adverse climatic conditions. In this sense, the RRIM 600 genotype is recommended as a promising material that would best adapt under adverse climatic conditions.

Gas Exchange, Root Morphology and Nutrients in Maize Plants Inoculated with Azospirillum brasilense Cultivated Under Two Water Conditions

HIGHLIGHTS Azospirillum brasilense stimulates root growth in maize under water deficit. Maize inoculated with A. brasilense shows greater photosynthesis under drought conditions. Under water deficit, maize plants inoculated with A. brasilense showed greater water use efficiency (WUE).

Abstract The objective of this study was to evaluate the gas exchange, root morphology and nutrient concentration in maize plants inoculated with A. brasilense under two water conditions. The experiments were carried out in a greenhouse, one under irrigation and the other under water deficit. The treatments consisted of four A. brasilense inoculants (control (without inoculation), Az1 (CMS 7 + 26), Az2 (CMS 11 + 26) and Az3 (CMS 26 +42). At the V6 plant stage, water stress was imposed on maize plants for 15 days. The phytotechnical characteristics, gas exchange, root morphology, root dry matter and macronutrient analysis were evaluated after 15 days of water deficit imposition. The water deficit caused a reduction in the development of maize plants. The presence of A. brasilense Az1 under the same condition yielded higher photosynthesis, carboxylation efficiency, water use efficiency, and greater soil exploration with increased length, surface area and root volume of plants. Inoculation by A. brasilense increased root system volume by an average of 40 and 47% under irrigation and water deficit, respectively, when compared to non-inoculated plants. The inoculant Az1 attenuated the deleterious effects caused by drought and yielded the best growth of the root system, resulting in the tolerance of maize plants to water deficit.

BIOFLOC: sustainable alternative for water use in fish culture / BIOFLOCO: alternativa sustentável para uso de água na piscicultura

Este estudo objetivou avaliar o desempenho do crescimento e o consumo de água de alevinos de tilápia-do-nilo (Oreochromis niloticus) criados em tecnologia de Biofloco (BFT) e no sistema tradicional. Alevinos de tilápia-do-nilo foram divididos em dois tratamentos: peixes criados em BFT e em sistema convencional. Os peixes foram alimentados três vezes ao dia, com 6% da biomassa corporal. O oxigênio dissolvido e a temperatura foram mensurados duas vezes ao dia; o total de sólidos suspensos, o pH, a alcalinidade, a amônia, o nitrito, o nitrato e o fosfato foram monitorados duas vezes por semana. Após 42 dias, avaliou-se o desempenho do crescimento da tilápia-do-nilo. A temperatura (25,1 e 21,7°C), a alcalinidade (37,1 e 16,9mg L -1 ), o nitrito (48,4 e 0,0mg L -1 ) e o nitrato (134,3 e 0,0mg L -1 ) foram maiores no BFT do que no sistema convencional. A sobrevivência (95,80 e 100,00%), a conversão alimentar (1,00 e 1,39), a conversão alimentar de todos os insumos (1,14 e 1,39) e o volume de água para produzir 1,0 T de peixe (128,21 e 23.934,42m³) foram menores, assim como a proteína, a eficiência (2,24±0,21 e 1,58±0,31) e a produtividade (7,77±1,39 e 0,61±0,07kg.m -3 ) foram maiores para o BFT do que para o sistema convencional. A tilápia-do-nilo criada em BFT apresenta dados produtivos iguais e/ou melhores que os obtidos em sistemas tradicionais, consumindo menos volume de água.(AU)

Evapotranspiração e eficiência do uso da água no primeiro ciclo produtivo da figueira 'Roxo de Valinhos' submetida a cobertura morta / Evapotranspiration and eficience of water use in first production cicle of the fig tree 'Roxo de Valinhos' under mulching

Avaliou-se a evapotranspiração (ETc) e a eficiência do uso da água (EUA) pela figueira 'Roxo de Valinhos' submetida à irrigação e cobertura morta (bagacilho de cana-de-açúcar triturado) no primeiro ciclo produtivo, nas condições edafoclimáticas de Botucatu, São Paulo. Empregou-se o método do balanço hídrico do solo e para a obtenção da evapotranspiração de referência foi utilizado o método Penman Montheit FAO 56. Para a avaliação dos coeficientes de cultivo (kc) adotou-se a seguinte distribuição fenológica: fase 1 - entre o transplantio e 20% do desenvolvimento vegetativo (DV); ii) fase 2 - de 20 a 80% DV; e iii) fase 3 ­ frutificação. Observam-se ETc acumulados de 409,4 e 465,8 mm em 254 dias após o transplantio (DAT) e médias de 1,47 e 1,67 mm dia-1, com e sem cobertura morta (CC e SC). Os coeficientes de cultivo (kc) médios foram de 0,16; 0,43 e 0,49 para SC e de 0,18; 0,44 e 0,50 para CC, entre as fases 1 e 3, respectivamente. Os valores de EUA diminuem com o aumento do volume de água recebido e variaram entre 1,65 e 3,32 kg de figos verdes por m3 de água irrigada para SC e CC.

Evaluated the evapotranspiration (ETc) and the efficiency of water use (USA) by the fig tree 'Purple Valinhos' submitted to irrigation and mulching (bagacilho of sugar cane crushed) in the first production cycle, at conditions of Botucatu , St. Paul. We used the method of soil water balance and to obtain the reference evapotranspiration method was used Montheit FAO Penman 56. For the assessment of crop coefficients (kc) we adopted the following phenological distribution: phase 1 - between transplanting and 20% of the vegetative (DV), ii) phase 2 - 20 to 80% DV, and iii) phase 3 - fruiting. Observe the cumulative ETc 409.4 and 465.8 mm in 254 days after transplanting (DAT) and averages of 1.47 and 1.67 mm day-1, with and without mulching (CC and SC). The crop coefficients (kc) mediums were 0.16, 0.43 and 0.49 for SC and 0.18, 0.44 and 0.50 for CC, in phases 1 and 3, respectively. The EUA values decrease with increasing the volume of water received and ranged between 1.65 and 3.32 kg of green figs per m3 of water for irrigated SC and CC.

Fluxo de biomassa e estrutura do dossel em capim-braquiária manejado, sob lâminas de irrigação e idades de crescimento / Biomass flow and canopy structure in brachiaria grass managed under irrigation depth and growth ages

Objetivou-se avaliar o fluxo de biomassa e a estrutura do dossel do capim-braquiária manejado sob cinco lâminas de irrigação (3,84; 4,39; 6,19; 8,62 e 10,46 mm dia-1) e quatro idades de crescimento, num delineamento inteiramente casualizado em arranjo de parcelas subdivididas, sendo as lâminas de irrigação, estudadas nas parcelas, e as idades de crescimento (10, 17, 24 e 31 dias), nas subparcelas, com quatro repetições. Constatou-se interação entre lâminas de irrigação x idades de crescimento para a altura do dossel. Verificou-se resposta quadrática com ponto de mínimo para a relação folha/colmo e eficiência de uso da água em função do avanço nas idades de crescimento. Constatou-se resposta linear crescente para a taxa de alongamento foliar e taxa de alongamento dos colmos com o incremento nas lâminas de irrigação. Constatou-se resposta crescente para a biomassa de forragem verde, biomassa de lâmina foliar verde, relação material vivo/material morto, densidade populacional de perfilhos e índice de área foliar com o avanço nas idades de crescimento. As idades de crescimento mais avançadas proporcionam incremento na biomassa de forragem e a irrigação favorece o fluxo de biomassa do capim-braquiária.

This research aimed to evaluate the biomass flow and canopy structure of Brachiaria decumbens under five water supply (3.84, 4.39, 6.19, 8.62 and 10.46 mm day-1). A completely randomized with split-plot design of five irrigation depth being the plots and growth ages (10, 17, 24 and 31 days), the subplots, with four replicates were adopted. It was interaction found between irrigation depth and growth ages for the canopy height. Quadratic responses were observed to the leaf/stem ratio and water use efficiency with minimum value in function to the advance in growth ages. It was observed positive linear response to the leaf elongation rate and stem elongation rate with the increase in irrigation depth. It was found positive linear responses to the green forage biomass, green leaf biomass, green material/dead material, tiller population density and leaf area index with increasing growth ages. The growth ages increment the herbage biomass and the irrigation improve favor the biomass flow of Brachiaria grass.

Ordenamento agroambiental das áreas de afloramento do aquífero guarani: estudo de caso nos estados de São Paulo, Goiás e de Mato Grosso / Agrienvironmental ordainment of the recharge areas of the Guarany aquifer: case research works in São Paulo, Goiás and Mato Grosso states (Brazil)

O presente trabalho procurou mostrar que a organização do espaço territorial agrícola, em forma de ordenamento agroambiental, constitui instrumento de grande relevância nos estudos ambientais, sobretudo em áreas de grande vulnerabilidade natural ou de alta fragilidade, como as áreas de afloramento ou recarga direta de aquíferos sedimentares, a exemplo do Aquífero Guarani. Para esse estudo foram adotadas duas áreas representativas da recarga direta desse aquífero, sendo a primeira caracterizada pela microbacia do córrego Espraiado, localizada na região de Ribeirão Preto/SP (Domínio Pedomorfoagroclimático do Planalto Médio Paulista) e a segunda pela depressão ou nascentes do rio Araguaia (Domínio Pedomorfoagroclimático homônimo), localizada em parte dos estados de Goiás (margem direita) e de Mato Grosso (margem esquerda). Os procedimentos consistiram na integração de informações sobre as áreas em questão, relacionadas à geologia (material de origem do solo), classificação dos solos, vulnerabilidade natural, riscos de contaminação do lençol freático, capacidade de uso dos solos, cobertura vegetal em consonãncia com o Código Florestal Brasileiro e, ainda Boas Práticas Agrícolas (BPA).

Reúso de água para fins industriais: estudo de caso lavanderia hospitalar / Reuse of water for industrial uses: case study hospital laundry

Objetivo: A escassez de água já é uma realidade para o Brasil, uma vez que os mananciais nos grandes centros urbanos encontram-se com sua capacidade de exploração no limite. Entretanto, outros fatores têm contribuído para agravar o quadro, entre os quais: as estiagens prolongadas dos últimos tempos, e o desperdício de água praticado pela população. O objetivo do presente trabalho consiste na definição de uma tecnologia apropriada para lavanderia hospitalar, visando o reúso de água, o que acarretará uma sensível economia e também contribuirá para a melhoria do meio ambiente, uma vez que minimizará o descarte de efluentes da rede coletora. Métodos: Foi realizado um estudo de caso, em uma lavanderia hospitalar para a execução da pesquisa, porque não existem muitos estudos referentes a reúso neste segmento. Os recursos metodológicos que foram utilizados no estudo, englobaram: pesquisa bibliográfica acerca de reúso de água, especialmente o reúso industrial; visitas técnicas ao local para coleta de dados e informações; análise de ensaios de laboratório e compilação de dados. Resultados: Foram disponibilizados dados de análise laboratorial existentes. A lavanderia não possui nenhum sistema de tratamento de seus efluentes e Constatou-se a necessidade de implementar um sistema visando o reúso de água. Conclusões: Em função do alto custo da empresa para captação da água e lançamento na rede coletora, deverá ser implantado um sistema de reúso. Além disso, os efluentes deverão atender aos critérios de limites máximos para lançamento de efluentes no estado de São Paulo. Sendo assim, foi selecionado um sistema de tratamento que atenda às necessidades da lavanderia, e acarrete uma minimização de danos ao meio ambiente, uma vez que os descartes serão reduzidos.

Objective: The shortage of water is a reality to Brazil, since the sources in great urban areas are with its exploration capacity reaching the limit However other fàctors have contributed to worse the situation, among which: long dry season, and water waste by population. The objective of this paper consists in defining the apropriate technology to hospital laundry, aiming the water reuse, which will deal to great savings as well will improve the enviroment considering the fact that it will reduce the effluents discharging in the sewage system. Methods: It was conducted a case study, in a hospital laundry to execute the research, due the lack of studies concerning reuse segment The methodological resources that were used in such study covered bibliographical research about water reuse, especially industrial reuse; technical visits to the sites for data collection and information; laboratory analysis; compilation of results. Results: Existing laboratory analysis were made available. The laundry doesn't have any effluents treatment system and was becoming clear the necessity to implement a water reuse treatment system. Conclusion: Taking into account the high costs in intake water and discharge, will be clear a reuse system implementation. Moreover those effluents should be bellow the discharges limits in São Paulo state. Therefore was selected a treatment system that will fullwell to laundry needs, and will minimize environment damages, since the effluents discharges will be reduced.