The objectives of the study were: to emphasize the public goods associated to soybean crop; and to qualitatively appreciate the multi-annual variation of soil biodiversity cohabitating with the soybean roots and the Rhizobium bacteria. The researchers were performed in the Eastern part of the Romanian Plain, in Southern Bărăgan Plain, Perișoru region. The soil is Vermic Chernozem (according to SRTS-2012 and WRB-SR-2014) formed in carbonate loess like deposits. The climate is temperate continental with the average annual temperature of 10.8°C, and the average annual precipitation of 480 mm. The main environmental public goods associated with the soybean crop and analyzed in this paper were: 1) soil quality and land capability; 2) water quality and availability; 3) biodiversity of agricultural land. Soil quality was analyzed based on the analytical data of physical, hydro-physical and chemical parameters of the soil. The land capability was quantified based on the values of the ecopedological indicators used for the land evaluation, both for land favourability and land quality. In this respect, for soybean, 72 points were obtained, which included the land from the studied site in the third class of favourability. The quality and the availability of water resources are also public goods associated with soybean crop, thus the water from the wells (located in the studied plot) was analyzed, the data showing normal limits for all analyzed water parameters. Regarding the multi-annual variation of the biodiversity, under intensive/irrigated soybean crop, the soil biodiversity did not change, while the upper-ground biodiversity was closely related to the plant changes into the crop rotation and consequently, many species being specialized accompany each crop within the crop rotation.

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The objective of the paper was to emphasize the characteristics of the poral space (quantified according to their size and shape) of an intensely irrigated soil, representing the habitat for soybean roots and Rhizobium bacteria nodulation. The studied site is located in Southern Bărăgan Plain, Perișoru region. The soil is Vermic Chernozem (according to SRTS-2012) formed in carbonate loess like deposits. The climate is temperate continental with an average annual temperature of 10.8°C, and an average annual precipitation of 480 mm. The poral space was quantitatively evaluated at microscopic scale, using image analysis on oriented soil thin sections with the help of an image-analyzer computer. The image analysis allowed the quantitative evaluation at microscopic scale of the undisturbed structure and the adjacent porosity, in 2-D dimension (in thin sections). The pores were divided according to their shape in three classes (regular, irregular and elongated pores), and further each shape class was divided into seven size classes according to the equivalent pore diameter (ranging between 100 and >1000 µm). The result showed, unspecific conditions in the studied Chernozem, thus: Ap horizon was more compacted than the underlined Apt, consequently the total porosity was lower (0.21 m2 m-2 ) into the top Ap horizon, comparing to the underlined Apt (0.33 m2 m-2 ). In agreement with the data obtained by means of image analysis (pores quantified according to their size and shape), the oriented thin sections gave a clear representation of the genesis, location and the characteristics of the poral space. The soybeans roots developed mainly into the areas with intense biological activity. The soil macro- and mesofauna proved to be good habitat builders for soybean roots and the Rhizobium nodules, even in the conditions of a droughty period with the irrigation application delay.