Tag Archives: dynamics

281-290 A. Pocius, P. Šniauka and A. Pushnov
Influence of dynamical factors on safe work with a fertilizer spreader
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Influence of dynamical factors on safe work with a fertilizer spreader

A. Pocius¹, P. Šniauka¹ and A. Pushnov²

¹Lithuanian University of Agriculture, Studentų 11, Akademija, LT―53361, Kaunas district,Lithuania; e-mail: antanas.pocius@lzuu.lt; povilas.sniauka@lzuu.lt
²Moscow State University of Environmental Engineering, Staraya Basmannaya 21/4,105066 Moscow, Russia; e-mail: pushnovas@gmail.com

Abstract:

The efficiency of mineral manure most often depends on the evenness of its distribution. The dynamics of the spread of the particles of the mineral manure in regard to the fixed and variable parameters of the imitative model of the spreader have been analyzed. The programmable location of a particle on soil depends on the movement trajectory of the particle on the disc and in the air, which eventually determine the final distribution of particles.The research considered the flow of the manure particles from the spread opening of themanure-box, the trajectory on the disc and in the air, the place of a particle on the surface of the ground as well as on how these trajectories depend on the characteristics of the spreader and particles. The trajectory of particle in the air is the function of its initial velocity and direction, by which the particle leaves the surface of the disc. It determines the final place of the particle on the surface of soil with respect to disc.One of the accidental factors influencing the trajectory of a particle is the impact of spreaderlean on hilly soil on the discharge angle of manure particles and the distance of particle fly in the distribution sector.The dependence of the spreading distance of the manure particles on the initial speed of theparticle and the trajectory angle of a disc has been obtained. It was established that when the aggregate moves, the trajectory angle changes due to the roughness of the ground from the one that was set constructively up to the largest value when a particle flies farthest.Under the influence of random factors, the angle between the spreader’s disc plane and aplane of soil surface can increase up to 8 degrees; therefore the distance of particle’s wafting increases.

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21-30 V. Eremeev, A. Lõhmus and J. Jõudu
Effects of thermal shock and pre-sprouting on field performance of potato in Estonia
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Effects of thermal shock and pre-sprouting on field performance of potato in Estonia

V. Eremeev, A. Lõhmus and J. Jõudu

Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences(EMU), Kreutzwaldi 64, EE51014 Tartu, Estonia;e-mail: Viacheslav.Eremeev@emu.ee

Abstract:

Pre-sprouting (PS), and to a lesser degree, pre-planting thermal shock (TS) had positive effects on tuber yield and other performance indicators. The experiment was carried out during the 2000, 2001 and 2002 growing seasons in the Department of Field Crop Husbandry of the Estonian University of Life Sciences. An untreated control (0) was comparedοοwith TS (2 days at 30 C, then 5 days at 12–15 C in a lighted room just prior to planting) and PSο(35–38 days before planting in a humid (85–90%) and lighted room at 12–15 C). All treatments were applied to three varieties: ‘Agrie Dzeltenie’ (early), ‘Piret’ (medium early) and ‘Ants’ (medium late). In the present study, the TS accelerated the emergence of plants by 2–5 days and PS by 7–12 days. Averaged over 3 years and 3 varieties, maximum leaf area index (LAI, 3.9 units) was reached 74 days after planting (DAP) and on the 50th day after emergence. Maximum LAI was 3.7 at 72 DAP for PS, 3.8 at 73 DAP for TS, and 4.1 at 76 DAP for the control. TS accelerated the beginning of tuber formation by about 5 days compared to the control, but the tuber yield of the control equalled TS from 65 days onward. Tuber formation began even slightly earlier in the PS treatment, and tuber yield exceeded PS throughout the season. All treatments reached maximum yield by 120 DAP.

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115–122 V. Eremeev, J. Jõudu, A. Lõhmus, P. Lääniste and A. Makke
The effect of pre-planting treatment of seed tubers on potato yield formation
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The effect of pre-planting treatment of seed tubers on potato yield formation

V. Eremeev, J. Jõudu, A. Lõhmus, P. Lääniste and A. Makke

Department of Field Crop Husbandry, Estonian Agricultural University, Kreutzwaldi 64, 51014 Tartu, Estonia; e-mail: slava@eau.ee

Abstract:

In the trials conducted in 2000–2002, we examined possibilities for growing potato using different methods of pre-planting treatment of seed tubers.
The varieties exploited were ‘Varajane kollane’ (early), ‘Piret’ (medium early) and ‘Ants’ (medium late). There were used the following ways of treatment for all varieties: PS – pre-sprouting, TT – thermal treatment and 0 – tubers not treated.
The dynamics of tuber yield formation during the vegetation period was significantly influenced by the weather. In terms of potato growth, weather conditions were the most favourable in 2001. The weather in 2000 and 2002 was not the most suitable for potato growth and development, and the yield in these years proved lower than the three-year average.
The average results from the three years show that potatoes could not realise their full potential to reach maximum yield. Pre-planting germination and thermal treatment had positive effects during the entire vegetation period, the effect being stronger at the beginning and then gradually decreasing.
Pre-planting treatment of seed tubers had a different effect on varieties with different growing times.
A comparison between the varieties showed that ‘Piret’ and ‘Varajane kollane’ started to form tubers early and thus exceeded the development of the variety ‘Ants’ until the 60th day of growth. ‘Ants’ reached its maximum yield, 47.0 t ha-1, already by the 114th day, followed by the fast-ripening ‘Varajane kollane’ and the medium-ripening ‘Piret’. Thermal treatment did not give any advantage in terms of total yield formation compared to untreated seeds, except for the pre-planting germination variant of the variety ‘Varajane kollane’, the total yield of which exceeded that of its untreated variant by 7.08 t ha-1.

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