The researches object in this paper consists in theoretical and experimental researches of the optimization possibility for the energetic consumption to preparing the germination bed in greenhouses with the digging soil machine.The technology for preparing the germination bed in greenhouses is an ensemble of activities, works and agricultural operations, economical and agro technical justified, ordered and carried in time, respecting the established condition and using a précised  range of machines and agricultural equipments. In these works the overthrow, the raising, the shredding, the levelling, the compaction and the modelling of soil takes place. Most times to these works may be associated land cleaning from remaining plants of the previous farming, the organic and chemical fertilizer, thermal and chemical disinfestations, marking of the plantation station etc., which transforms the preparing of the germination bed into an important energy consumer. In most technologies for preparing  the germination bed, is included also the digging soil work, by which the overthrow, the raising and the shredding is realized .The digging soil machines in greenhouses are build on several principles (with plane movement, by throwing furrow back parallel with the direction of advancing, with lateral soil digging towards right, with working organs having a rotation movement ), in all these cases the energy consumption being high. Based on the kinematics and dynamics research of these machines, a complex mathematical model  of the energy consumption on digging soil in greenhouses is made, on which afterwards an optimization study is realized. Mainly, the mathematical model presented in this paper offers the possibility  for theoretical research on energy consumption variation depending on the speed and depth work. Results that digging the same surface with increased working speed helps  reducing the specific energy consumption, in particular due to influenza of step size screeds on this parameter.  At the same time the energy consumption of digging soil work increases with  increasing the work depth. The theoretical researches were completed with important experimental researches, effectuated with an agricultural aggregate composed of tractor U 445L and digging soil machine in greenhouses MSS 1,40 , both manufactured in Romania.  For researches accuracy was necessary a soil monitoring, for humidity and   resistance to penetration, by using a latest generation equipments.  It was consisted  an optimal soil humidity existence from a agricultural view but also the digging resistance. Also the hardened the soil is (higher soil penetration)  the greater the energy consumption is on digging soil work. The energetic consumption on digging soil work was experimental determinate by measuring the combustible consumption (for  working and free movement ), for different speed and depth works. The experimental energetic consumption values were compared with the theoretical obtained values, allowing a correct mathematical model to be realized. Based on this model, researches which can assure an optimal energy consumption for preparing the germination bed with digging soil machines in greenhouses can be done. The concrete results are presented in the paper.

greenhouses; soil digging machine; energetic consumption; optimization

Presentation: oral