Paulo Sérgio Lourenço de Freitas

Lixiviação de nutrientes em solo cultivado com aplicação de água residuária de suinocultura

This work aimed to evaluate the impacts on leachate from drainage lysimeters receiving application of different rates of pig farming residual water (PRW) during soybean crop cycle. The experiment was conducted at the Agricultural Engineering Experimental field of UNIOESTE. The soil was classified as Rhodic Ferralsols. There were twenty-four drainage lysimeters where soybean cultivar CD 214 was sown. Four PRW rates (0; 100; 200 and 300 m3 ha-1) were applied to the soil seven days before sowing in a single application combined with two fertilizations (with and without recommended dose) during sowing, and three repetitions per treatment. Three leachate collections were carried out in each experimental plot. The first was conducted 40 days after sowing (DAS); the second at 72 DAS, and the third at the end of crop cycle (117 DAS). pH, calcium, magnesium, potassium, phosphorus, and total nitrogen were evaluated. Based on the results, it was possible to observe that pH and Mg values in the leachate did not suffer influence of PRW application and fertilization. K+, P and Ca+2 in the leachate were higher for higher PRW rates.

Impacto da água residuária de suinocultura no solo e na produção de capim-elefante

ABSTRACT Intensive pig farming concentrates a great number of animals per area generating high volume ofwastewater, which requires correct disposal since it might cause environmental imbalance. Pig farmingwastewater (PFW) can be used as fertilizer due to its characteristics. This study aimed to evaluate the effectof applying pig farming wastewater on chemical properties of Dystric Nitosol and on elephant grass( Pennistum purpureum Schum) production. An experiment was carried out in field conditions consistedof five treatments plus control. T 0 = without PFW application (control), T 1 = 150 m 3 ha -1 , T 2 = 300 m 3 ha -1 ,T 3 = 450 m 3 ha -1 , T 4 = 600 m 3 ha -1 , T 5 = 750 m 3 ha -1 PFW applied during elephant grass crop cycle. P,K + , Mg +2 , Ca +2 concentrations were obtained in the soil before and after PFW application. Phosphorusconcentration in the soil increased as a function of PFW application rates increase. Al +3 concentrationdecreased. PFW application did not influence plant height and dry mass production of the grass.

Estudo exploratório do uso da vinhaça ao longo do tempo: I. Características do solo

The aim of this study was to accomplish an exploratory study of the stillage in the areas with sugarcane, through a comparative and systematic analysis. The present work was conducted in the company USACIGA - Sugar, Alcohol and Electric Power S.A. located at Gaucha, northwest Parana state. Treatments constituted of areas cultivated with sugarcane and submitted to different times of stillage application, respectively 1, 2, 3, 4, 12 and 20 years, and a reference area, without application. In all the studied areas trenches of 1 m3 were opened, geo referenced in 340 m of altitude for accomplishment of the soil classification and sample collection. The evaluations were performed of the density, soil particle density, organic carbon, cation exchange capacity (CEC), total porosity, soil water moisture for the sugarcane, besides the relationships among K, Ca, Mg and V%. The results indicated that the stillage application contributed to the organic carbon and potassium increase in the soil and that the sugarcane productivity presented a direct relationship with the ratio of potassium adsorption increase in the soil.

Agroclimatic aptitude of oil seed plant in the region of Tangará da Serra, Mato Grosso state, Brazil

Resumo - O objetivo do presente trabalho foi determinar a aptidao agroclimatica da cultura do pinhao manso (Jatropha curcas) na regiao de Tangara da Serra. Utilizaram-se historicos de dados diarios de precipitacao e temperatura do ar, disponibilizados pelo Instituto Nacional de Meteorologia (INMET) e Agencia Nacional de Aguas (ANA), analisando-os conforme as exigencias climaticas da cultura. A regiao em estudo demonstrou caracteristicas favoraveis ao desenvolvimento do pinhao manso, com precipitacao media anual variando de 1.260,1 mm a 1.815,5 mm e temperatura media entre 24,4 °C e 26,1 °C. A temperatura media mensal encontra-se nos niveis ideais da cultura, mas o regime pluviometrico mensal indica periodos longos de baixos niveis de precipitacao, principalmente durante os meses de junho, julho e agosto, com media inferior a 30 mm. De modo geral a regiao em estudo e classificada com aptidao plena para o cultivo do pinhao manso, no entanto, a utilizacao de tecnologias de irrigacao pode maximizar a produtividade, uma vez que o regime hidrico e um elemento climatico limitante em alguns periodos do ano. Palavras-chave - Jatropha curcas. Aptidao agricola. Clima.

Estudo exploratório do uso da vinhaça ao longo do tempo: II. Características da cana-de-açúcar

This work was conducted in the Cidade Gaucha PR, with the objective to evaluate the mechanical resistance of soil, the levels of calcium, magnesium, potassium, base saturation in the soil, the roots distribution and yield of sugarcane fertigated with wastewater (stillage) of sugarcane industry for 1, 2, 3, 4, 12 and 20 consecutive years and a control without application. The soil compaction was evaluated with penetrometer cone to 0.50 m depth in intervals of 0.02 m. The results of chemical analysis of soil samples collected between the depths of 0 to 0.20 and 0.20 to 0.40 m were evaluated. The root density was evaluated with the weight of the dry matter of roots with the monolith method retreats to each 0.10 m depths to 0.50 m. The high soil mechanical resistance occurred where wastewater of sugarcane industry was applied for 20 years. The concentration of calcium decreased after two years of application of wastewater, accompanying the fertility of the soils not showing direct connection with the productivity as well as the magnesium. The concentration of the potassium in soil presented linear relation with the productivity. The roots of the sugarcane presented a direct relation with the application time of wastewater of sugarcane industry

Avaliação de sistemas de irrigação por gotejamento, utilizados na cafeicultura

Este trabalho foi conduzido no periodo de agosto a outubro de 1999, com o objetivo de avaliar os sistemas de irrigacao por gotejamento utilizados na cafeicultura irrigada do norte do Espirito Santo e nas areas de cerrado de Minas Gerais e caracterizar a porcentagem de area molhada (PAM) nesses sistemas de irrigacao. Foram realizadas medidas das dimensoes do bulbo molhado para determinacao da porcentagem de area molhada. Pelos resultados obtidos verificou-se que, dos valores de coeficiente de uniformidade de distribuicao determinados, apenas um sistema apresentou valor abaixo de 70%, refletindo uma uniformidade ruim. No que se refere aos demais resultados, dez sistemas indicaram valores de uniformidade de distribuicao entre 70 e 80%, oito sistemas mostraram valores entre 80 e 90% e doze sistemas apontaram valores acima de 90%, indicando uniformidade razoavel, boa e excelente, respectivamente. Dos valores determinados, a maioria dos sistemas que apresentaram uniformidade de boa a excelente estava situada na regiao de cerrado de Minas Gerais. Com relacao a PAM, os valores determinados variaram na faixa de 19 a 100% e apenas um sistema apresentou valor abaixo do limite minimo recomendado para regioes umidas, que e de 20%.

Impacts of the application of swine wastewater in percolate and in soil cultivated with soybean

The aim of this study was to evaluate the possible impacts caused in the soil and in the percolate in lysimeters of drainage with application of different rates of swine wastewater (SW) during the cycle of soybean culture and to assess the productivity of it. The experiment was conducted at the Agricultural Engineering Experimental Center of UNIOESTE. The soil was classified as typical Distroferric Red Latosol. There were twenty-four drainage lysimeters in the area in which the soybean was cultivated, cultivar CD 214. Four SW depths (0; 100; 200 and 300 m3 ha-1) were applied to the soil seven days before the sowing in a single application combined with two mineral fertilizations in the sowing (with and without recommended fertilization during sowing), and three repetitions per treatment. It was realized three collections of percolate in each experimental portion, the first was conducted 40 days after sowing (DAS); the second at 72 DAS, and the third at the end of crop cycle (117 DAS). It was evaluated in the percolate the pH, calcium, magnesium, potassium, phosphorus, and total nitrogen. Based on the results, it was possible to observe that the level of K, P and N in the soil increased according tothe increase of SW rates. The levels of K and P in the percolate were higher for higher rates of SW. The productivity was not influenced by the application of SW or by fertilization.

Soil water evaporation under densities of coverage with vegetable residue

This study was conducted at the Agronomic Institute of Parana (IAPAR) in Londrina, State of Parana (PR), Brazil (latitude 23o18S, longitude 51o09W and average altitude of 585 m). The local climate, according to the classification of Koeppen, is Cfa type, i.e., humid subtropical climate, with rain in all seasons and can occur dry seasons during the winter. It was determined soil evaporation (E) under different coverage densities with residue from the wheat crop. The treatments were installed in weighting lysimeters of 2.66 m2 and 1.3 m deep, which allows to determine E by the mass difference with measuring precision of 0.1mm at one hour intervals. Treatments consisted of 0; 2.5; 5 and 10 t ha-1 of wheat crop residues, placed evenly over each lysimeter. In the first cycle (September 22nd to October 20th, 2008), the reduction of E, as compared to a bare soil, was 4; 15 and 24%, while in the second cycle (December 1st to 30th, 2008), the reduction was of 15; 22 and 25%, respectively, for the treatments of 2.5; 5 and 10 t ha-1.

Soil water balance simulated by CROPGRO-Drybean model for edaphoclimatic conditions in Maringá

The performance of the CROPGRO-Drybeans model for the prediction of soil water balance, as well as growth components and bean crop yield, was assessed using data from two field experiments conducted at the State University of Maringa Irrigation Technical Center, Parana - Brazil, (latitude 23o27S, longitude 51o57 and altitude 542 m), during the 2005 and 2006 growing season. The model simulations correlated well with measured soil moisture (r > 0.7) for both experiments. However, there were high discrepancies between measured and simulated soil moisture values on the days after rainfall. In addition, it was found that the model exaggerates the effect of water stress during the flowering phase, which leds to underprediction (19 and 29%) of crop yield.

Teor de nitrato em alface hidropônica em função de vazões e períodos de pós-colheita

The objective of this study was to determine the nitrate (NO3-) content present in lettuce plants (Lactuca sativa L.) of the Vera cultivar, produced under hydroponic system, in function of different flow rates and post-harvest periods. The experiment was conducted in the city of Cascavel-PR, in a greenhouse of the Universidade Estadual do Oeste do Parana (UNIOESTE). The plants were nourished by the use of a nutrient solution, characterized by mean electrical conductivity of 1.2 dS m-1 which after passing the entire growing bench, returned to the irrigation tank and restarted the process, forming a closed system. The experiment was conducted in completely randomized design with eight replications, which were represented, individually, by two lettuce plants, in the factorial scheme (3 x 4). The treatments resulted from the combination among three flow rates (0.5; 1.0; and 1.5 L min-1) and four post-harvest storage periods (0; 24; 48; and 72 h). The nitrate content was determined by the colorimetric method and the obtained values were lower than the maximum limit required by the European Community. The investigated factors influenced significantly the mean levels of nitrate.