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Increasing operational efficiency of the seeder distribution system for cereal crops

Author: Gheorghița Andrei
Degree:doctor of engineering
Speciality: 05.20.02 - Electrification and Automation of Agriculture
Scientific adviser: Vladimir Serbin
doctor habilitat, professor, Agrarian State University of Moldova
Institution: Agrarian State University of Moldova


The thesis was presented on the 14 April, 2021
Approved by NCAA on the 30 July, 2021


Adobe PDF document1.19 Mb / in romanian


CZU 631.331.81

Adobe PDF document 6.99 Mb / in romanian
142 pages


sowing; sowing machine; fluted roller type dosing device; transportation system; uniformity of distribution; distribution system


Thesis structure: introduction, four chapters, general conclusions and recommendations, bibliography from 112 titles, 3 annexes, 122 pages of essential text, 148 figures and 21 tables. The obtained results are published in 6 scientific works and 1 patent.

Purpose of thesis: improving the technological indicators of cereal crops sowing quality by optimizing the constructive-functional parameters of the seed distribution system for cereal sowing machines.

The objectives of the thesis: summary of information on increasing the distribution system efficiency of cereal crops sowing machines, classification, ways of improvement; theoretical- experimental, computer-assisted research of dosing process, distribution and transportation of seeds based on the developed 3D model; elaboration of operation process theoretical bases of the seed dosing and transport system towards the incorporation place; elaboration, based on theoretical research, of the experimental samples and carrying out laboratory tests on stand, in the soil channel and in the production conditions, with the evaluation of the functional capacities and imposed agrotechnical indices; arguing the parameters and operating regimes of seed distribution and transport system based on obtained results.

The scientific novelty and originality: consist in the theory elaboration and design of pneumomechanical system for seed dosing and transportation, the values of the optimal constructive and technological parameters of the system were established and establishing the mathematical regression model of the variation coefficient of seed distribution along the row. Results: the use of experimental distribution system in the composition of cereal seed drills allowed to reduce the coefficient of variation of distance between seeds, when distributing along the row, down to 39.22% and increase the working speed of the aggregate up to 12 km/h.

The theoretical significance: consists in argumentation of the theoretical bases for determining the optimal parameters of the dosing and transportation devices from the distribution systems of the sowing machines.

The applicative value: the research results served as a basis for design elaboration and justification of the optimal parameters of the pneumomechanical dosing and transportation system. They can be used to modernize existing drilling machines and new one’s design, which operate at increased working speeds which will increase the crop by 9.91%.

Implementation of scientific results: the research results were implemented in EDS “Petricani”, as well as LTD „Vadalex-Agro” and JSC „ATC-Agrotehcomerț”.