Search

The correct feeding of fresh air in a stock-breeding farm is a decisive factor for achieving high quality microclimate sustenance. Distributed dozed feeding of input air is a method, allowing for the achievement of best microclimate parameters in the animal zone, while at the same time making the most efficient use of the energy, emitted in the premises. The application of this method requires constant control of energy and temperature-humidity processes in the farm on the basis of a mathematical model.This paper aims at developing a model, describing the processes in a stream, fed into stock breeding farm premises.

Modelling the progress of air stream parameters in space and time as applied to a stock-breeding farm is a basis for implementing higher quality microclimate control, based on modern information technology, using powerful mathematical models. It permits, through simulation of control processes and the progress of microclimate parameters within a farm's space, for a given combination of conditions, to choose parameters of control in a way to provide the best conditions for the animals in their inhabited zone, while making the most efficient use of energy, emitted within the premises. Such an approach to microclimate control improves the energy efficiency of the process.This paper aims at algorithmic modelling of different physical processes, represented as separate subroutines, describing the processes within a stream of air, fed into a stock-breeding premise.

The paper describes past, present and future status of Agricultural Engineering according to their social, economic and scientific role in the countries of South East Europe. Besides mentioned, the paper has clearly defined role, objectives and future activities for Bio - systems Engineering Societies.

The paper describes past, present and future status of Agricultural Engineering according to their social, economic and scientific role in the countries of South East Europe. Besides mentioned, the paper has clearly defined role, objectives and future activities for Bio - systems Engineering Societies.

Soil acidity of pseudoglay and similar soils is main limiting factor of field crops yield in Croatia. A combination of soil management practices, including liming is a solution encountered for improvement of crop production in acid soils. In this study was shown survey of liming experiments, which have been conducted in the last two decades period. The field experiments with liming were conducted in the period from 1980 to 2000. Depending on the trial, hydrated lime (90% CaO), calcite (51% CaO) and carbocalk (waste of Osijek sugar factory: about 37% CaO) were used. They were conducted in four replicates. Three liming experiments were conducted from 1980 to 1986. In general, maize, soybean and barley grain yields increased due to liming by 10% or less than 10%, while wheat showed no response to lime application. Also, the effects of liming were depended on soil characteristics and the year of testing. For example, by application of 32 t calcite/ha, grain yield of corn in Valpovo trial was increased for 10% and in Mikanovci trial it decreased for 10%. Yield decreasing due to liming is impossible to explain by applied soil test. Waste products from manufacturing processes using limestone or similar raw materials (for example, carbocalk - wastage from sugar factory can be used for neutralizing soil acidity. Growing of ten corn hybrids and carbocalk application (15 t/ha) on Djakovo pseudogley for the 1993 growing season resulted by yield increases, depending on hybrids from 6% to 45%. In general, liming is useful for soil fertility and yield increases on most acid soils of the Eastern Croatia. For this reason, based on our experiences, we could to recommend liming with waste from sugar factory and other liming materials for increasing field crops yields on acid soils.