HYDROPONIC DEVICES FOR GREEN FODDER PRODUCTION: A REVIEW

In traditional farming, plants require a lot of space (growing area), they consume a large amount of water, absorb a small percentage of nutrients in soil and are completely dependent on meteorological conditions. Therefore, growing crops in this way entails high costs and a high risk of invested funds. One of the measures to reduce these factors is the use of hydroponics.In the study six types of hydroponic systems (HS) plant constructions based on plant nutrient supply technology were reviewed: ebb and flow HS; nutrient film technique (NFT) HS; aeroponics; deep water culture HS; “wick” HS and drip-irrigation HS. In addition, a review of the structural design of the hydroponic systems identified their advantages and disadvantages in green fodder production.The most promising technology for the cultivation of green fodder is the NFT HS. This cultivation technology is appreciated in feed production for its highly utilized growing room volume and closed-loop irrigation solution to plants, which allows it to be easily automated based on solution parameters. Seven farms already have this technology in place in Lithuania. In order to optimize hydroponic fodder cultivation technology, it is expedient to improve NFT equipment and process control systems

Weed Control by Chemical and Mechanical Means

Vytauto Didžiojo universitetasŽemės ūkio akademij

Tarybinė liaudis – nauja žmonių bendrija

1971 m. Vilniaus aukštosios partinės mokyklos vyr. dėstytojas Anatolijus Smirnovas Maskvoje, Aukštojoje partinėje mokykloje prie TSKP CK apgynė filosofijos mokslų kandidato disertaciją „Tarybinė liaudis ir socialistinės nacijos kaip jos sudėtinės dalys“. Oficialieji oponentai: filos. dr. F. Konstantinovas, filos. kand. A. Sercova. Disertacijoje nagrinėjama, kaip formuojasi nauja istorinė žmonių bendrija – tarybinė liaudis, koks ryšys tarp jos ir tarybinių socialistinių nacijų kaip jos sudėtinių dalių, jų vaidmuo ir vieta komunizmo statyboje. Ši problema analizuojama teoriniu ir metodologiniu požiūriu

Socialinės tikrovės ir sąmoningumo santykio klausimu

There is always dialectical interdependence between social reality and consciousness. Consciousness is formed under immediate influence of social reality and effects in turn changes in it. Men of high consciousness are more active in changing social reality, with a view of reaching still higher social ideals. Dependence of social reality and the process of consciousness formation is the expression of the dialectical interrelation of social being and consciousness. It is the expression of dependence of social properties of man and his spiritual world on the surroundings, concrete social relations, the place and function he performs in a given society. This is why the success of educational work depends largely on due regard for objective influence of social reality on the process of consciousness formation.Straipsnyje, remiantis K. Marxo idėjomis, svarstomi visuomeninės tikrovės ir žmogaus dvasinio pasaulio dialektiniai santykiai. Teigiama, kad socialinė tikrovė, arba visuomeninis gyvenimas, yra visuminės gamybinės, visuomeninės žmonių veiklos ir dvasinio žmonių gyvenimo vienybė, arba visuomeninės būties ir visuomeninės sąmonės sąveikos ir tarpusavio sąlygotumo rezultatas. Dvasinis visuomenės gyvenimas suponuoja visą žmogiškojo proto veiklos visumą ir daugiapusiškumą. Tai visuomeninės būties atspindėjimas individualia ir visuomenine sąmone, kurios pasireiškia moksle, ideologijoje, visuomeninėje ir individualiojoje psichologijoje. Tiesioginę įtaką sąmonės vystymuisi daro materialiniai visuomeniniai santykiai, pirmiausia gamybiniai. Sąmoningumas yra būdinga žmogaus sąmonės savybė, kurios esmę sudaro aktyvus santykis su socialine tikrove, tikslingas jos pertvarkymas panaudojant visuomenės vystymosi dėsnius. Socialinė tikrovė ir sąmoningumas visada susiję dialektiškai – straipsnio autoriaus nuomone, tokia metodologinė samprata leidžia giliau išanalizuoti komunistinio sąmoningumo formavimo dėsningumus

Silage production technology using grass thickening vibratory method

The article presents silage production technology using vibratory method. The objective of this research was to quantify the selected theoretical model by comparison to experimental results and to determine more reasonable calculations methods for practical issues. Based on the classical theory of mechanical oscillations a numerical analysis of silages thickening by vibrator was developed. Using the developed numerical model, the vibrator operational characteristics were obtained. Numerical and experimental investigation was performed using a direct-action vibrator to compact chopped maize. A comparison between the experimental and numerical results is presented. The results can be used to determine technical characteristics of the vibrator for silage thickening dynamics. The obtained system parameters can be used to prepare technical tasks for selection of vibratory silages thickening equipment

Analysis of corn ears movement within the threshing crescent using high-speed recording method

The main objective of the research was to establish movement of corn ears within the threshing crescent between the cylinder and the concave using high-speed recording method. Tangential threshing unit was used in the experimental trials. Cylinder rotation and linear velocity of rasp bars (11.00 m s-1, 14.14 m s-1 and 17.28 m s-1) were determined by using threshing cylinder covered with filler plates having 4 different shapes. During the trials, speed of corn ears within threshing crescent, number of impacts received by the corn ear, rising height of the corn ear after impact of rasp bar and time between two impacts of rasp bar to the corn ear, depending on the shape of filler plates of threshing cylinder were found. Video analysis of corn ear movement showed that the speed of corn ears movement in the threshing crescent highly depends on linear velocity of rasp bars. The average speed of corn ear within threshing crescent and number of impacts received by the corn ear were increased with increase of linear velocity of rasp bars irrespective of cylinder filler plates are used. Moreover, both above-mentioned parameters were larger in the second part of concave length than in the first one. A tendency of increase of the corn ear moving over the surface of the concave and decrease of number of impacts received by the corn ear was observable by reduction in the threshing crescent. Following reduction of linear velocity of rasp bars to 14.14 m s-1, it would be reasonable to cover the threshing cylinder with filler plates that can reduce the cross-section area between rasp bars and concave (to 94.26 cm2 in view of one gap between adjacent rasp bar). In this case, filler plates showed a substantial effect on behaviour of corn ears: they restrict a rising height of the corn ear, may be subject to additional rotational motion, deflect the corn ear to the clearance between the rasp bar and the concave bar as well as deflect threshed kernels towards concave grates

Reduction in adverse environmental impacts associated with the operation of combine harvesters during the harvesting of winter oilseed rape

When harvesting winter oilseed rape (WOSR), leaving higher (~0.3–0.4 m) crop stubble is an effective method of reducing fuel consumption and contaminant emissions of a combine harvester equipped with the tangential threshing apparatus and straw walkers. At a speed of 4 km h−1, when the stubble height of WOSR was increased from 0.2 to 0.4 m, the mass of material other than grain (MOG) fed to the harvester was reduced by 7 t h−1, resulting in a reduction of 6.2 l h−1 in fuel consumption, 5.7 kg h−1 in carbon equivalent (CE), and 16.3 kg h−1 in CO2 emissions. A more accurate estimate of harvester performance is the fuel consumption per ton of threshed seeds. On increasing the MOG mass feed rate to 15.6 t h−1, the fuel consumption per ton of threshed rapeseeds decreased to 3.33 l t−1, CE reached 40.2 kg h−1 or 3.0 kg t−1, and CO2 emissions reached 121.3 kg h−1 or 9.2 kg t−1 of threshed rapeseed. When optimizing the automatic speed control system of the combine harvester, the MOG mass feed rate, the permissible limit of seed losses, and fuel consumption per ton of threshed seeds must be considered

Effect of variable rate seeding on winter wheat seedbed and germination parameters using soil apparent electrical conductivity

Due to the variability of soil characteristics in the field and the rising prices of high-quality seeds, farmers are increasingly interested in applying a system of precision variable rate seeding (VRS), which makes it easier to manage risks in crop production and allows to ensure the profitability of the farm. Most modern seed drills are equipped with a hydraulic or electric drive and a terminal in the tractor cabin, allowing farmers to apply VRS. The aim of this study was to determine the most appropriate seeding rate of winter wheat according to the measured apparent soil electrical conductivity (ECa) in the field, to investigate the uniformity of seed placement by layers in the soil and to evaluate the germination dynamics of winter wheat. Precision seeding was performed using a VRS map, generated from soil ECa data obtained by field surface scanning using the ECa device EM-38 MK2. Winter wheat seeding was implemented with a direct seed drill. The research was carried out by measuring the parameters of winter wheat seedbed and germinated plants, including the number and distribution of seeds in soil layers of different depths, germination, tillering. Field research was performed with 3 treatments and 4 repetitions (1 - uniform rate seeding; 2 - VRS; 3 - VRS + variable rate fertilisation (VRF)). The results of the research showed a direct relationship between the soil ECa and the depth of seed placement. Most seeds were inserted at medium depths (15-30 mm), except in the soil management zone, where ECa was highest (28.8 mS center dot m(-1)). In this area, most seeds (50.7%) were inserted shallowly up to 15 mm. The experimental results of seeding studies showed that using the VRS and VRS + VRF methods in all soil zones the germination of winter wheat was similar, while seeding at the uniform rate yielded significant differences between individual soil zones