Lúcia Helena Pereira Nóbrega

Nonpoint source pollution by swine farming wastewater in bean crop

In order to verify the environmental impact of the application of swine farming wastewater in bean crop, an experiment was set up in the Experimental Farm of PUCPR - Toledo, PR, Brazil. Runoff and soil samples were collected at the end of the experiment. Four wastewater treatments were utilized during the experiment (50, 100, 150 and 200 m3 ha-1) and the without wastewater as the control. The results demonstrate that (i) the amounts of potassium, phosphorus, and nitrogen in runoff are exponential, (ii) that phosphorus has a seven-fold polluting potential compared to potassium and three-fold compared to nitrogen, and (iii) that the mobility of potassium in the soil profile is the largest, followed by those of nitrogen and phosphorus.

Cobre e zinco no material percolado e no solo com a aplicação de água residuaria de suinocultura em solo cultivado com soja

O objetivo deste trabalho foi avaliar possiveis efeitos da aplicacao de taxas de agua residuaria de suinocultura (ARS), quanto as concentracoes de cobre e zinco, tanto no solo quanto na agua percolada de lisimetros de drenagem, durante o ciclo da cultura da soja. O experimento foi conduzido em ambiente protegido, onde havia 24 lisimetros de drenagem. Semeou-se soja cultivar CD 202, e foram aplicadas ARS nas seguintes dosagens: 0; 100; 200 e 300 m3 ha-1 no ciclo, combinadas com duas adubacoes na semeadura (com e sem adicao da adubacao recomendada na semeadura), em tres repeticoes por tratamento. Foram feitas seis coletas do material percolado durante o ciclo da cultura e realizadas determinacoes de cobre e zinco. No solo, foram feitas tres coletas em cada parcela experimental, para a determinacao do pH, da materia orgânica, da capacidade de troca cationica, do cobre e do zinco. O delineamento foi em blocos casualizados, num esquema fatorial de 4 x 2. Observou-se que o cobre no solo nao apresentou diferencas significativas com a aplicacao de ARS e adubacao, enquanto as concentracoes de zinco no solo foram influenciadas pelas taxas aplicadas de ARS. As transferencias de cobre e de zinco por percolacao foram pouco expressivas.

Ions leaching in deformed and undeformed soil columns

Neste trabalho, foi avaliada a dinâmica da lixiviacao de ions em colunas de solo deformado e indeformado. O solo utilizado era proveniente de area fertirrigada com agua residuaria da suinocultura diluida em 0%, 25%, 50%, 75% e cultivada com soja. Foram construidas curvas de eluicao para nitrato, potassio e condutividade eletrica. De acordo com os resultados obtidos nas colunas de solo deformado, e proporcionalmente aos tratamentos, o nitrato apresentou maior mobilidade, seguido pela concentracao de sais totais e do potassio. A metodologia de colunas de solo indeformado nao se mostrou adequada, devido, possivelmente, a compactacao do solo durante a amostragem e a dificuldade no bloqueio de caminhos preferenciais ao longo de toda a coluna.

Aplicação de água residuária de suinocultura em solo cultivado com soja: cobre e zinco no material escoado e no solo

The objective of this work was to evaluate the diffuse pollution regarding to the copper and to the zinc in the soil and in the runoff material due to the application of swine wastewater (ARS) in soil cultivated with soybean, under simulated rain condition. The experiment was installed in Toledo - PR, Brazil, and it was applied to the soil five rates of ARS (0; 50; 100; 150 and 200 m3 ha-1 in the cycle), in three replications for treatment, divided in six applications along the cycle of the soybean. Gutters were installed gutters to collect the runoff material and it was made six rain simulations during the experiment, resulting in six collections of the runoff. At the end of the soybean cycle, soil samples were collected in each one of the experimental plots, at three depths, for pH determination, cation exchangeable capacity, organic matter, copper and zinc. It was observed that there were copper and zinc losses through runoff and the largest copper concentrations were verified at 20-40 and 40-60 cm depths, while the zinc presented larger concentration in the top layer 0-20 cm and it increased in the other depths.

Behavior of the forms of nitrogen in soil grown with corn irrigated with swine wastewater

A utilizacao de agua residuaria com caracteristicas quimicas capazes de complementar ou substituir a adicao de fertilizantes quimicos tem beneficiado amplamente, tanto em regioes onde ocorre a necessidade de se fazer uso de irrigacao, quanto em solos que necessitam de fertilizantes. Porem, uma preocupacao ambiental e agronomica deve sempre persistir no uso dessa tecnica. Dessa forma, o presente trabalho teve como objetivo avaliar o comportamento das formas de nitrogenio no material percolado e no solo quando cultivado com milho (Zea mays L.) irrigado com agua residuaria da suinocultura (ARS), em quatro taxas de aplicacao (112,5; 225; 337,5 e 450 kg N ha-1) e adubacao convencional (AD), em dois niveis (15 e 25 kg N ha-1). O trabalho foi desenvolvido com a implantacao de lisimetros, posterior a realizacao das irrigacoes com ARS, e coleta das amostras de solo nas profundidades 0-20; 20-40 e 40-60 cm. A partir dos resultados encontrados, concluiu-se, que no solo, houve tendencia de aumentar a concentracao do nitrogenio inorgânico em funcao da taxa de ARS e do tempo. No material percolado, observou-se maior concentracao de nitrato proporcional as taxas de ARS.

Management zones definition using soil chemical and physical attributes in a soybean area

Several equipments and methodologies have been developed to make available precision agriculture, especially considering the high cost of its implantation and sampling. An interesting possibility is to define management zones aim at dividing producing areas in smaller management zones that could be treated differently, serving as a source of recommendation and analysis. Thus, this trial used physical and chemical properties of soil and yield aiming at the generation of management zones in order to identify whether they can be used as recommendation and analysis. Management zones were generated by the Fuzzy C-Means algorithm and their evaluation was performed by calculating the reduction of variance and performing means tests. The division of the area into two management zones was considered appropriate for the present distinct averages of most soil properties and yield. The used methodology allowed the generation of management zones that can serve as source of recommendation and soil analysis; despite the relative efficiency has shown a reduced variance for all attributes in divisions in the three sub-regions, the ANOVA did not show significative differences among the management zones.

Software para estimativa do custo operacional de máquinas agrícolas - MAQCONTROL

The rational mechanization has as main objectives the selection and optimization of mechanized systems. An adequate purchase of agricultural machinery is not sufficient if its use is not controlled in operational and financial aspects. This work describes the development of software to estimate operational costs of agricultural machinery (MAQCONTROL), using Borland Delphis development environment and Firebird database. The operational costs were divided in fixed and variable. In fixed costs, the expenses with depreciation, interest, storage and insurance were estimated. In variable costs, the emphasis was given to the expenses on maintenance, lubricating oils, filters, tires, grease, fuel, small repairs, and parts replacement. Results have shown the software efficiency for the proposed objectives. Therefore, the MAQCONTROL software proved to be an important tool in the rural management process, because it reduces information costs and accelerate the precise determination of operational costs of farm machinery.

Alterações no tempo de cozimento e textura dos grãos de feijão comum durante o armazenamento

Objetivou-se, no presente trabalho, foi comparar alteracoes no tempo de cozimento e dureza dos graos de duas variedades de feijao comum, durante o envelhecimento natural e o acelerado. O envelhecimento de um lote de cada variedade de feijao (Iapar 81 variedade carioca e Iapar 44 - variedade preto) foi acelerado em estufa a 40oC e 76% de UR% por 15, 30, 45, 60, 75 dias. Outro lote, das mesmas variedades, foi submetido ao envelhecimento em condicoes ambientais por tres, seis, nove e doze meses. O lote-controle foi armazenado a 5 oC. Apos cada tempo de armazenagem, foram determinados os parâmetros de tempo de cozimento e dureza. Os graos da variedade carioca apresentaram maiores tempos de cozimento em relacao ao feijao preto, em ambos os sistemas de armazenagem. O feijao cozido da variedade carioca apresentou dureza maior que o feijao da variedade preto, tanto no envelhecimento acelerado quanto no envelhecimento natural. A dureza dos graos cozidos e resfriados a temperatura ambiente foi superior a dos graos resfriados a 60 oC, visto que a temperatura influenciou nas medicoes, provavelmente pela maior retrogradacao do amido a temperatura ambiente. O envelhecimento acelerado por vinte dias foi equivalente a um ano em condicoes naturais, em relacao a dureza dos graos.

Uso de manipueira no desenvolvimento vegetativo do milho em ambiente protegido

This study evaluated the effects of the wastewater of cassava industry, treated by pond system, on the corn crop. The irrigation with wastewater resulted in an increase in chemical parameters of the soil, proportional to the respective treatments in the following order: L1E (effluent of the decantation pond), L1ED (effluent of the pond of decantation with 50% dilution), L2E (effluent of the first anaerobic pond), L2ED (effluent of the first anaerobic pond with 50% dilution), L3E (effluent of the second anaerobic pond), L3ED (effluent of the second anaerobic pond with 50% dilution) and T (control without fertilization and irrigation with water) except for the treatment TA (control with fertilization: 85 kg ha-1 K2O; 60 kg ha-1 N; 100 kg ha-1 P2O5 and irrigation with water:); the height of plant for the treatments varied in the following order: L1E, TA, T which differed significantly followed by L1ED, L2ED and L3ED statistically similar; and L2E and L3E which also showed similar results without significant differences at 5% probability level. The number of leaves did not present significant differences among the evaluated treatments, only the concentrations of phosphorus and zinc in the leaves and roots presented significant differences.

Variation on the amount of winter cover crops residues on weeds incidence and soil seed bank during an agricultural year

This study analyzed possible interferences associated to the amount of crop residues produced by the black oats and the consortium of black oats, common vetch and forage turnip on weeds incidence and soil seed bank. It was a field trial with seven treatments and five replications. The cover crop was sown at throwing, cut at 100 days and residues were put on each respective plot, using a proportion of normal amount of produced straw, either its half and double. The heaviest weights were obtained from cover crop consortium and their application decreased weeds incidence in such area. The seeds bank and other analyzed parameters did not show statistical differences. According to these results, it was concluded that winter cover crop could be used in crops rotation with soybean.