Assessment of Climatic Resources and Recommended Agrotechnics Practices in the Transylvanian Plain, Romania
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Lucrări Ştiinţifice – vol. 56 (1) 2013, seria Agronomie ASSESSMENT OF CLIMATIC RESOURCES AND RECOMMENDED AGROTECHNICS PRACTICES IN THE TRANSYLVANIAN PLAIN, ROMANIA Teodor RUSU1, Ileana BOGDAN1, Paula Ioana MORARU1, Adrian Ioan POP1, Camelia COSTE1, Bogdan DUDA1 e-mail: [email protected] Abstract The Transylvanian Plain (TP), with an area of 395,616 hectares is an important agricultural production area of Romania. During the last two hundred years, TP has been undergoing considerable anthropic impact, currently being a hilly area with serious issues of sustainability of soils, scarce in water resources, with deficient rainfall and an extremely low degree of afforestation: 6.8%. Monitoring the thermal and hydric regime of the area is essential in order to identify and implement sets of measures of adjustment to the impact of climatic changes. Soil moisture and temperature regimes have been evaluated on a basis of a set of 20 data logging stations positioned throughout the plain. Each station stores electronic data of ground temperature on 3 different levels of depth (10, 30 and 50 cm), of soil humidity at a depth of 10 cm, of the air temperature at 1 meter and of precipitation. The multiannual average air temperature situates between 9.35-12.040C and grow in the soil with increasing depth to 9.89-12.82°C – at 10 cm; 10.05-12.85°C – at 30 cm; 10.03- 12.86°C – at 50 cm. The multiannual average air temperatures during the period 2008-2012 increased with 0.15(north) - 2.84(south) C as compared to the multiannual average temperature of the area (9.2°C). The thermal regime of the ground is of the mesic type, multiannual average soil temperature at 50 cm depth situating between 10.03-12.86°C and the differences between the average summer temperatures and average winter temperatures range between 11.35- 17.72°C. Monitoring the hydric regime of the soils in TP demonstrate that the moisture regime is of the ustic type for the northern and north-western part, whereas for the southern and south-eastern part the hydric regime is of the xeric type; the soil being dry over 45 consecutive days following the summer solstice. The analysis of recorded data results in a situation similar to the southern, south-eastern and eastern slopes- lower rainfall with approx. 43.8 mm, higher temperatures with 0.370C in air, with 1.910C at 10 cm, with 2.220C at 20 cm and with 2.430C at 30 cm in soil, compared to northern, north-western and western slopes. These issues, supplemented by those of slope require special agrotechnical measures generated by TP relief. Key words: soil temperature, soil moisture, precipitation, Transylvanian Plain. Since the Earth's climate is being generated greenhouse effect, which increases with 330C the by certain factors, such as: solarisation, the average global temperature atthe Earth's surface as eccentricity of the terrestrial orbit, the Earth's compared with the possibility in which these precession movement, obliquity in relation to the greenhouse gases wouldn’t exist. This layer Sun, the terrestrial albedo, anthropogenic factors, determines the average temperature of the Earth moisture, terrestrial surface, it cannot remain surface of 150C, its absence would lead to a constant as long as changes occur and an evolution temperature of -180C. This natural warming is a at the terrestrial crust takes place (O. Bogdan and condition of the presence of water, in its liquid E. Niculescu, 1999; K. Brysse et al., 2013). Solar form, on the terrestrial surface, which is the basis radiation is the main source of heat, its average of biological existence. A larger amount of energy, value at the Earth level is 0.8-1.5 calories/cm2/min which occurs as a result of the intensification of (T. Rusu, 2005; M. Coman and T. Rusu, 2010). the greenhouse gases, which have been emitted The solar radiation that reaches the Earth is anthropically during the last 50 years, may result reflected back into space. Part of these radiations is into a new climate (O. Ranta et al., 2008; K. retransmitted towards the Earth's surface by a layer Hemadi et al., 2011; J. Ramirez-Villegas et al., of "greenhouse gases", leading to an increase of the 2012; A. L. Lereboullet et al., 2013). temperature in the atmosphere. The appearance of According to the climatologists who have life on the planet is possible due to the natural reconstructed temperatures, the last decade of the 1 University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, 3-5, Manastur street, 400372, Cluj- Napoca, Romania 151 Universitatea de Ştiinţe Agricole şi Medicină Veterinară Iaşi twentieth century and early twenty-first century is supported by the fact that six of the warmest years the warmest period of the past 2000 years (C. M. of the 20th century were registered in the 1990’s. Raymond and G. M. Robinson, 2013; V. Contrary to its name, the TP is not a Srinivasan et al., 2013). The risks brought about by geographically flat plain, but rather a collection of climate changes are real and their impact has rolling hills, approximately 300 m to 450 m above already become perceptible, and the fact that the sea level in the south, and 550 to 600 m above presently have been recorded the highest levels of the sea level in the north (N. Baciu, 2006). The CO2 and CH4 has been demonstrated by climate of the TP is highly dynamic, ranging from researchers (J. Fuhrer, 2003; W. J. Eastwood et al., hot summers with high temperatures of >30°C to 2006; H. J. Fowler et al., 2007; M. Casas-Prat and very cold winters with lower temperatures J. P. Sierra, 2012). Climate changes represent a approximately -10°C (Climate Charts, 2007). problem of global policy. Scientific evidence and For the period 1967-2000, the TP is explanations of climate change have been characterized by multiannual average temperatures accumulated over several decades, being integrated of 9.2°C in the south (Turda station) and 9.10C in into strategies and policies of adaptation (EEA, the north (Targu Mures station) and the average 2009; A. Aaheim et al., 2012; J. Beck, 2013). multiannual precipitations being of 510 mm/year in Romania is classified among the areas with the south (Turda station) and 567 mm/year in the the lowest capacity to adapt to existent climate north (Targu Mures station). In these change and to those likely to generate, and the circumstances, the purpose of the research Transylvanian Plain (TP) is one of the most conducted is to monitor climate, thermal and affected areas (ESPON, 2011). Currently, and in hydric regime of the soils in TP and to elaborate the future, a series of strategies and plans to measures of adaptation to climate change. The TP, counter climate change are being put forward, but with an area of 395,616 hectares, is an important their implementation requires a strict monitoring of agricultural production area of Romania. the area’s thermal and hydric regime, in order to identify and implement the measures for adaptation MATERIAL AND METHOD to the impact of climate change. In Romania, there has been a significant Transylvanian Plain is a subunit of the increase in the average annual temperature. Over Transylvanian Basin, along with Tarnavelor the last century, this growth has been around Plateau and Somesan Plateau. The Transylvania 0.50C. Thermal growth accentuated during the last Basin is a "natural fortress" which communicates decades, beginning with the second half of the with the extracarpathical areathrough "gates" twentieth century, reaching values 0.80C - 10C on which have emerged from tectonic fragmentation, and, through these connections, the western air extended areas in Romania. Concerning the masses, wetter and hotter, penetrate. The name of precipitations, a slight reduction in the rainfall TP is not in accord with its structural elements, but amount on an annual basis at the level of the entire it is used due to its climate, to anthropic activity, country has been reported during 1901-2007, being and especially due to the methods of using the decreased to 50 mm (NMA, 2011). land for agriculture. Although it looks just like a National Meteorological Agency (NMA, constant and uniform relief, of the hilly type, some 2011) forecasts for Romania, as compared to the differences arise which require the division of the period 1980-1990, an average annual warming as TP. In specialty literature, there has been the one projected for Europe, namely an increase attempted a regionalisation of the TP, so as to be of the temperatures: between 0.5-1.5°C for the better characterized by the name it bears, over the years being recorded by different terminology (H. period 2020-2029; between 2.0- 5.0°C for 2090- Cacovean, 2005): The Someselor and The Mures 2099. For the period 2090-2099, scientists estimate Plains, or the Transylvanian High Hills Plain and a pluviometric deficit during summer (10-30%) the Transylvanian Low Hills Plain. and an increase in rainfall during the winter (5- The thermal and hydric regime monitoring of 10%). Because the scarcity of water will be more the TP (soil temperature and humidity, air and more accentuated, agriculture will be greatly temperature and precipitations, fig. 1) has been affected, but at the same time the population will achieved during the period 2008-2012. Twenty suffer from hardly adapting to extreme datalogging HOBO Micro Stations (H21-002, On- temperatures very likely manifest several days set Computer Corp., Bourne, MA, USA) have been consecutively (P. Moraru and T. Rusu, 2010). deployed across the TP on divergent soil types, slopes, and aspects (fig.