Evandro Chartuni Mantovani

Desempenho de uma semeadora-adubadora para plantio direto, em dois solos com diferentes tipos de cobertura vegetal

O desempenho operacional de uma semeadora-adubadora de plantio direto, versao soja e milho, foi avaliado em um Podzolico Vermelho-Amarelo câmbico, fase terraco, e um Latossolo Vermelho-Amarelo, da Zona da Mata de Minas Gerais. A maquina foi testada em tres tipos de cobertura do solo e em duas velocidades de trabalho. Por ocasiao do plantio, foram avaliados a patinagem do trator e da semeadora-adubadora, o consumo de combustivel e a potencia exigida, a distribuicao de fertilizante e o nivel de danos as sementes. Depois do plantio, foram avaliados o numero de sementes distribuidas, o estande final, a profundidade de plantio e a distribuicao longitudinal da semente. A uniformidade de distribuicao longitudinal foi avaliada pela porcentagem de espacamentos aceitaveis, distribuicao dupla e falhas na distribuicao, e pelo coeficiente de variacao dos espacamentos entre sementes. A demanda de potencia foi maior no Podzolico, por sua maior densidade e resistencia a penetracao. Independentemente do tratamento, o numero de sementes distribuidas e o estande final nao apresentaram diferencas significativas. As sementes distribuidas nao tiveram sua qualidade afetada pelos dosadores da maquina. A analise de variância nao indicou diferenca significativa entre os porcentuais de espacamentos aceitaveis, a distribuicao dupla e as falhas.

An Automatic Data Acquisition and Control Mobile Laboratory Network for Crop Production Systems Data Management and Spatial Variability Studies in the Brazilian Center-West Region

This paper describes all tools and procedures used to structure and implement an automatic data acquisition and control mobile laboratory network for crop production systems data management and spatial variability studies in the Brazilian Center-West Region. It was set up with base in remote sensing and microprocessor techniques, microelectronic devices, sensors, controls, sampling systems, data loggers, portable microcomputers, automatic data acquisition, RF communications link, and the global positioning system (GPS), allowing for the acquisition of spatially related data during tilling, planting, and harvesting. Physical chemistries and biological characteristics of the continuous soil-water-plant-atmosphere were monitored along of the crop growth period, at field conditions, seeking the rationalization of the agricultural inputs use and the performance improvement of agricultural systems. Some results are presented.

Sorção do herbicida imazaquin em Latossolo sob plantio direto e convencional

Abstract – The objective of this study was to evaluate the effect of spatial variation of pH and organic matter ofa Dark Red soil, under different managements, on imazaquin herbicide sorption. Soil-water sorption partitioningcoefficient (K d ) was used in surface soil samples collected at 0–15 cm layer in a 38 ha area, under central pivotirrigation and with till and no-till management. Herbicide sorption was most strongly related to soil organic mattercontent and pH, revealing greatest sorption in lower pH values with greater soil organic matter content. Thesesamples were collected at no-till management area. The pH effects on imazaquin retention occur either bycontrolling the organic matter ionization form as also its speciation. The clay content in the whole area had novariation, however, it didn’t affect the K d values. Using multivariate regression and two independent variables(soil organic matter content and pH), the prediction of herbicide sorption by soil was good (R 2 = 0.91).Index terms: imidazolinone, site-specific management, organic matter, pH, conventional-tillage.

Desempenho de dois sistemas distribuidores de sementes utilizados em semeadoras de milho

Corn (Zea mays L.) seed treatment with insecticide to control soil pests alters the surface roughness, difficulting seed to slide from the seed reservoir to the soil, affecting the performance of the seeder. The objectives of this work were to determine the effect of seed treatment with insecticides or graphite on the angle of repose of maize seed and to evaluate the effect of seeder velocity, chemical treatment, seed size and shape on the performance of two seed distribution systems: disc and fingers. The tests were performed in a laboratory, by using maize seeds of the cultivar BR 201, with different classifications, submitted to six chemical treatments, tested at two velocities, with two types of seed distribution system. The experiment was designed in randomized complete blocks, with three replications. All isolated factors and interactions were significant at 5% probability level. The use of the insecticides Furadan and Semevin made the performance of the seeder become better for the finger system and worse for the disc system. Adding graphite, at the dose of 4 g/kg of seed, improved performance to the levels before the chemical treatment, when using Semevin, and to levels slightly slower with Furadan.

Análise multivariada da resistência do solo à penetração sob plantio direto

In order to increase agricultural production, Brazil opted for the expansion of farming areas and the intensive use of mechanization, causing serious damage to soils. At the same time, conservation practices such as no-tillage farming are also in use. Nevertheless, soil density assessments are necessary in both situations. Practical and controversial, the methodology of penetrometry is the most utilized in such assessments. The objective of this study was to identify the vertical stratification of soil resistance to penetration. Data was collected in a Typic Hapludox under no-tillage. Samples were collected in forty points of a 50 x 50m grid. Soil resistance was evaluated in three different positions in each point: plant rows, between the plant rows, and in the rows of the tractor path. Measurements were taken using a hydraulic-electronic penetrometer. Factorial analysis with orthogonal rotation, a Multivariate Analysis technique, was used to analyze soil resistance of soil layers. Four layers were identified in the plant rows, when more superficial layers had higher relative variance. Three layers were identified in the plant rows and in rows of the tractor path, points of anthropic action; in this case, deeper layers had higher relative variance.

Avaliação de perdas em uma colhedora de fluxo axial para feijão

The evaluation performance of a harvester should include the energy needed for its operation, the harvesting capacity and the quantitative loss in the process. The objective of this work was to evaluate the performance of a bean harvester. Field tests were done in different operational conditions. Based on the collected data, it was concluded that the harvester header causes the greatest quantitative loss, responsible for 49.30% of the total loss. In the separation and cleaning systems the losses were 43.61 and 7.09%, respectively. The maximum harvesting capacity of the machine was 6.56 t h-1 of grains.

Automação do processo de avaliação de desempenho de tratores e implementos em campo

Power machinery and implements are being used in many regions of Brazil to support different grain production systems without proper adaptation for working in different soil and weather conditions. To help farmers and manufacters solve problems related to equipments, a performance test needs to be working under a similar field condition. The objective of this research was to evaluate an in-field performance test, using an automatic data acquisition system. The engine power demanded was calculated indirectly, by using the engine rpm and the fuel consumption data on the tractors calibration curves. The easiness of programming and operating the electronic instrumentation systems allowed to accomplish a great number of performance tests. The results showed very little difference between drawbar force measured and calculated obtaining 0.996 of correlation. The metodology used for in-field performance test showed to be a very powerfull tool to help farmers and the industry better manage their equipments and to improve performance.

Algoritmo para classificação de plantas de milho atacadas pela lagarta do cartucho (Spodoptera frugiperda, Smith) em imagens digitais

An image processing and analysis algorithm was developed to identify the fall armyworm damage on corn plants. The developed program segmented the larvae damage on the image in two stages: a coarse and fine classification. The coarse stage applied a threshold technique on image blocks of 60 x 60 pixels. The fine stage was based on a neural network classifier which classifies image blocks of 3 x 3 pixels. The algorithm accuracy was accessed by evaluating the error matrix based on 80 and 75 image blocks of the coarse and fine stages, respectively. The algorithm presented an overall accuracy of 80.74%.