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This study aims to evaluate the impact of different tillage systems on water conservation and penetration resistance in Stagnosols on slopes. Three tillage systems were evaluated during a long-term experiment in Central Croatia in a period from 2011 to 2014, in order to identify sustainable land management practices: control treatment (CT), ploughing and other seedbed layer preparation up and down the slope; ploughing across the slope (PA) – to 30 cm, other operations depending on the crop, also across the slope; and ploughing across the slope (30 cm) with subsoiling (SUB) to 50 cm. Penetration resistance and soil water content were measured each investigated season during five terms to a depth of 60 cm. Tillage systems significantly influence soil water content and penetration resistance, but the results showed great temporal and vertical variation in each investigated season. The results also showed that in low quality Pseudogley deep loosening is required because of the inability of these soils to recover naturally. The hardness of these soils decreases after tillage, or when the moisture content increases, so the period with potentially limiting soil impedance is shorter in systems with subsoiling than in conventionally tilled soils. Fallow has been effective in reducing soil strength in non-traffic areas and increasing soil moisture content. When comparing cropping variants it was established that only a system including subsoiling ensures higher moisture content. Results indicate that since soil water content and penetration resistance were adversely affected, subsoiling should be applied continuously in Pseudogley sites in the hills. Generally, soil resistance increased with time from the date of primary tillage. Although penetration resistance values increase after tillage, the differences were attributed to temporal variation of soil water content. In this study soil moisture condition is presented as a more important factor for soil resistance than the time between primary tillage and measurements.

The Republic of Croatia belongs to the Central-European, Adriatic-Mediterranean and Pannonian-Danube group of countries. It covers an area of 85, 677 km2, of which land area accounts for 56, 614 km2. The project Hydropedological Map of the Republic of Croatia was implemented using the ESRI program package and includes the Basic Hydropedological Map with the attribute database of hydropedological mapping units, pedological and hydropedological profiles and hydrological and hydropedological parameters. The cartographic attribute database of the Basic Hydropedological Map comprises hydropedological units – types of moistening by surface and/or ground water: automorphic excessively drained, automorphic well drained, automorphic moderately well drained, hydromorphic alluvial, hydromorphic pseudogleyic, hydromorphic pseudogley-gleyic, hydromorphic hypogleyic, hydromorphic amphigleyic and hydroameliorated. The soil water retention capacity of particular hydropedological units varies from 248 to 635 mm/m, water infiltration into soil ranges from 0.01 to 7.32 m/day, hydraulic conductivity for 1 m soil depth is from 0.01 to 6, 84 m/day, and from 0.01 to 15.6 m/day for 2 m depth. Annual effective precipitation of 25% occurrence probability varies from 551 to 2294 mm, and that of 75% occurrence probability is between 272 and 1180 mm. Maximum one-day runoff coefficient in the conditions of different soil texture and different vegetative cover ranges from 0.24 to 0.94 (25% probability) and from 0.02 to 0.89 (75% probability). Water deficit in soils of different texture (25% occurrence probability) varies annually from 0.0 to 513 mm/m, and deficit of 75% occurrence probability from 30 to 857 mm/m. Water surplus in soils of different texture (25% occurrence probability) varies annually from 57 do 1686 mm/m, and surplus of 75% occurrence probability ranges from 0.0 to 606 mm/m. The Applied Hydropedological Map of the Republic of Croatia comprises priority amelioration units for agricultural land reclamation and management, including drainage and irrigation, dry farming, forest and grasslands and afforestation, specified for the Black Sea and Adriatic basins.

The paper presents a comparison of two approaches to describing vehicle trafficability of cohesive soils. The first approach is based on soil consistency and Atterberg index indicators. The second approach is based on the cone penetrometer measurement and on the vane shear test, as well as on the EcoWood classification of soil strength. The research was carried out in the lowland region of pedunculate oak forests in the Sava River basin. Three cut-blocks of different moisture and forest soil strength were selected, in which timber was extracted by a forwarder. Measurements and sampling were carried out on undisturbed soil. Research results have shown that both approaches to describing vehicle trafficability of cohesive soils describe the soil strength of forest wilderness in a similar way and provide a good basis for developing a trafficability evaluation system, as a future task of forest engineering. The soil cone index and shear strength values calculated in this research do not concur with the classes of EcoWood soil strength classification and indicate that the limits and ranges of these parameters are questionable. The problem of defining the threshold values of soil strength parameters covered by this research will be the subject of future investigations.

The objective of this study was to determine the effect of application of different amounts of N fertilizer added by fertigation and different mulches on the total mineral N in the plough soil layer and yield of tomatoes. The two-year study (2007 and 2009) was conducted on hydromeliorated deep Terra Rossa near Pula. In two-factor experiment, set in a split-plot design, the main factor was N fertilization (NF) in three levels: 60 (NF1), 120 (NF2), and 180 (NF3) kg N ha-1. Subfactor was soil mulch (M), also in three levels: without mulch (WM), straw mulch (SM), and mulch with black polyethylene film (BPM). Different NF significantly affected the amount of N min in the soil. Only in 2009, mulch as well as interaction between NF and DAT had significant impact on the amount of N min in soil. Nitrogen fertilization did not significantly affect the total yields of tomatoes, except the application of NF2 and BPM that generated significantly higher yields of tomatoes in 2007. Recommended technology is application of NF2 and BPM, but with ecological point of view it would be justified to use the nitrogen fertilization with only 60 kg N ha-1.