Egidijus Šarauskis

Experimental analysis of CO2 emissions from agricultural soils subjected to five different tillage systems in Lithuania

Intensive agricultural production strongly influences the global processes that determine climate change. Thus, tillage can play a very important role in climate change. The intensity of soil carbon dioxide (CO₂) emissions, which contribute to the greenhouse effect, can vary depending on the following factors: the tillage system used, meteorological conditions (which vary in different regions of the world), soil properties, plant residue characteristics and other factors. The main purpose of this research was to analyse and assess the effects of autumn tillage systems with different intensities on CO₂ emissions from soils during different seasons and under the climatic conditions of Central Lithuania. The research was conducted at the Experimental Station of Aleksandras Stulginskis University from 2009 to 2012; and in 2014. The soils at the experimental site were classified as Eutric Endogleyic Planosol (Drainic). The investigations were conducted using five tillage systems with different intensities, typical of the Baltic Region. Deep conventional ploughing was performed at a depth of 230-250 mm, shallow ploughing was conducted at a depth of 120-150 mm, deep loosening was conducted at depths of 250-270 mm, and shallow loosening was conducted at depths of 120-150 mm. The fifth system was a no-tillage system. Overall, autumn tillage resulted in greater CO₂ emissions from the soil over both short- and long-term periods under the climatic conditions of Central Lithuania, regardless of the tillage system applied. The highest soil CO₂ emissions were observed for the conventional deep ploughing tillage system, and the lowest emissions were observed for the no-tillage system. The meteorological conditions greatly influenced the CO₂ emissions from the soil during the spring. Soil CO₂ emissions were enhanced as precipitation and the air and soil temperatures increased. Long-term investigations regarding the dynamics of CO₂ emissions from soils during the maize vegetation period indicated that autumn tillage systems affect the total soil CO₂ emissions. The highest (2.17 μmol m(-2)s(-1)) soil CO₂ emissions during the vegetation period were observed in the deep ploughing tillage system, and the lowest values were observed (1.59 μmol m(-2)s(-1)) in the no-tillage system.

The main physical properties of planosol in maize (Zea mays L.) cultivation under different long-term reduced tillage practices in the Baltic region

Abstract The impact of sustainable reduced tillage (RT) on the physical properties of soil is well documented worldwide; however, there is no precise information about the influence of long-term RT or no-till (NT) on the soils at the boundary for grain maize-growing in the semi-humid subarctic climate conditions of the Baltic states, especially on the formation of a hard-ened upper soil layer (10–15 cm in depth) — “loosening hardpan”. This study was carried out at the Research Station of Aleksandras Stulginskis University, Lithuania from 2009–2012. The investigations were based on a long-term (since 1988) field experiment. The aim of the investigation was to ascertain the influence of reduced primary tillage on the main soils physical properties. This study examined soils that were deep ploughing (DP), shallow ploughing (SP), deep cultivation (DC), shallow cultivation (SC), and no-till (NT). Reducing the tillage intensity to NT had no significant effect on the structural soils composition; however, the stability of the structure of the >1 and >0.25 mm-size fractions was significantly higher in the non-reversibly tilled (DC, SC) and NT plots. The penetration resistance of the DP soils was less after primary tillage and wintering, and became similar to the NT plots at the end of the maize growth season. After primary tillage and wintering, the soil moisture content in the upper soil layer (0–5 cm depth) of the NT plots was 17–49 and 16–18% higher than that in the DP. Long-term reduction of primary tillage up to NT generally had no significant effect on the moisture content and soil bulk density of the 0–10 and 10–20 cm layers. The results showed that long-term RT stabilized the physical quality of soil. Less soil penetration resistance was established in the DP plots compared to both RT and NT, however, indicators of the formation of a uniform “loosening hardpan” layer were not found. It is summarized that long-term RT or NT systems stabilize, or may increase, the physical quality of soil in crop cultivation with low inter-row coverage potential (maize), and could be applied in semi-humid subarctic climate conditions as a good option to prevent soil degradation.

The influence of biopreparations on the reduction of energy consumption and CO 2 emissions in shallow and deep soil tillage

The application of innovation in agriculture technologies is very important for increasing the efficiency of agricultural production, ensuring the high productivity of plants, production quality, farm profitability, the positive balance of used energy, and the requirements of environmental protection. Therefore, it is a scientific problem that solid and soil surfaces covered with plant residue have a negative impact on the work, traction resistance, energy consumption, and environmental pollution of tillage machines. The objective of this work was to determine the dependence of the reduction of energy consumption and CO2 gas emissions on different biopreparations. Experimental research was carried out in a control (SC1) and seven different biopreparations using scenarios (SC2-SC8) using bacterial and non-bacterial biopreparations in different consistencies (with essential and mineral oils, extracts of various grasses and sea algae, phosphorus, potassium, humic and gibberellic acids, copper, zinc, manganese, iron, and calcium), estimating discing and plowing as the energy consumption parameters of shallow and deep soil tillage machines, respectively. CO2 emissions were determined by evaluating soil characteristics (such as hardness, total porosity and density). Meteorological conditions such average daily temperatures (2015-20.3 °C; 2016-16.90 °C) and precipitations (2015-6.9 mm; 2016-114.9 mm) during the month strongly influenced different results in 2015 and 2016. Substantial differences between the averages of energy consumption identified in approximately 62% of biological preparation combinations created usage scenarios. Experimental research established that crop field treatments with biological preparations at the beginning of vegetation could reduce the energy consumption of shallow tillage machines by up to approximately 23%, whereas the energy consumption of deep tillage could be reduced by up to approximately 19.2% compared with the control treatment. The experimental research results reveal the reduction of CO2 emissions in shallow tillage to approximately 20.14% (and that in deep tillage to approximately 19.16%) when works were performed by different biological preparation usage scenarios. This experimental research demonstrates the efficient use of the special adaptation of a new biotechnological method for the reduction of the energy consumption and CO2 gas emissions of agricultural machinery.

Impact of living mulches on the physical properties of Planosol in monocropped maize cultivation

Abstract The complex mutual interactions between soil properties and plants in high-biodiversity mono-cropping agro ecosystems have not been widely investigated. For this purpose, during 2009-2011, a stationary field experiment was conducted at the Experimental Station of the Aleksandras Stulginskis University to establish the effect of a multi-component agrocenose (maize, living mulch, weeds) on the physical properties of the soil. Spring oilseed rape, white mustard, spring barley, Italian ryegrass, black medic, Persian clover and red clover were sown as living mulch into maize inter-rows. The stability of >1.0 mm aggregates increased between the beginning and end of the maize vegetative period in almost all of the crops containing living mulch. The greatest competition for moisture content between the inter-crops and maize was observed at the beginning of the vegetative period because of living mulches of long growing seasons using the most moisture. In many cases, the shear strength of the soil was significantly reduced by the living mulch in the middle of summer, when it covered the maize inter-rows. These findings show that the monocropping of maize with living mulch stabilises or improves the physical characteristics of the soil, highlighting its potential for sustainable maize growing.

ASSESSMENT OF HERBAL PLANT BIOFUEL PELLET QUALITY INDICATORS

Variety of vegetable raw materials is used for energetic needs: logging and wood processing waste, agricultural production by-products: straws as well as specially cultivated trees, tall grass, rapeseeds, triticale and other herbaceous plants. In the performed scientific work, preparation and opportunities of use of energetic needs are estimated for non-conventional energy plants (elephant grass, orchard grass, common mugwort and fibrous nettle), technological parameters of processing these seeds and pressing into granules are explored, biometric and physic-mechanical properties of finished pellets are evaluated, and their resistance to impact forces is evaluate. Having examined humidity of pellets, it was found that maximum moisture content was in pellets of elephant grass and nettle – from 13.1 to 13.2%, while the smallest – in orchard grass pellets 10.0%. The largest density of non-conventional energetic pellet density was orchard – 983.8 kg m -3 DM (dry matter) and common mugwort – 926.7 kg m -3 DM, and density of elephant grass pellets was the lowest – 619.3 kg m -3 DM. Results on resistance to deformability of non-conventional energetic crops granules indicate that the highest resistance against external forces is a pellet made of common mugwort: they decompose to 110.03 N force. Pellets of other plants disintegrate to smaller external force: fibrous nettle granules – to 90.6 N, orchard – to 67.3 N force. Elephant grass pellets have the smallest resistance to deformation and decompose more quickly (at 20 N). The research results show that pellets made of elephant grass are of the lowest quality; due to this, it is not recommended to use these plants in the form of pellets. Keywords: energy plants, pellets, properties, compression resistance. Article DOI: http://doi.org/10.15544/RD.2015.008