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Nekoliko politika Europske unije (npr. Zeleni plan, Zakon o klimi, Strategija bioraznolikosti 2030., Od farme do stola) ima za cilj transformirati poljoprivredne sustave, a jedan od ciljeva je smanjenje primjene mineralnih gnojiva. Istraživanje utjecaja ugara i zelene gnojidbe na poboljšanje fizikalno-kemijskih značajki tla imala su za cilj utvrditi njihov utjecaj na promjene u tlu, kao i na prinos jarih kultura - kukuruza i soje. Dvogodišnjim istraživanjem u koji je uključen pravi ugar i zeleni ugar (uzgoj siderata kratke vegetacije - sjetva u jesen i unošenje u tlo u proljeće) utvrditi će se razina poboljšanja istraživanih parametara. Dvogodišnja istraživanja provedena su na OPG-u Dalibor Jurina u Velikim Zdencima, Bjelovarsko-bilogorska županija prema slučajnom bloknom rasporedu na parcelama veličine 10 x 35 m u četiri ponavljanja. Varijante uključene u istraživanje su: I. crni ugar ; II. crni ugar + zelena gnojidba ; III. usjev (2021 – kukuruz ; 2022 – soja) + zelena gnojidba i IV. usjevi 2021 – kukuruz ; 2022 – soja bez zelene gnojidbe. Ovim istraživanjem, potvrđeno je da zelena gnojidba utječe na promjene reakcije tla, stabilnost strukturnih agregata, povoljniji C/N odnos kao i na smanjenje zbijenosti tla u periodu od dvije godine dana (jesen 2020. – jesen 2022.). Nije uočena pozitivna korelacija između zelene gnojidbe i prinosa kukuruza u prvoj godini istraživanja, obzirom da se prinos pokazao manjim na tretmanu na kojem je primijenjena zelena gnojidba. U drugoj godini istraživanja prinos sjemena soje bio je viši na tretmanu sa zelenom gnojidbom. Potrebno je nastaviti istraživanja kako bi se utvrdile promjene fizikalnih i kemijskih svojstava i uočio utjecaj zelene gnojidbe na iste, kao i na prinos uzgajanih usjeva.

Water 15(13), 2398 - (2023). doi:10.3390/w15132398, Published by MDPI, Basel

Several European Union policies (e.g. Green Deal, Climate law, Biodiversity Strategy 2030, Farm to Fork) have a goal to transform the agricultural systems and one of the goal is fertilizers reduction. Nature based solutions (e.g. green manure) can help in restoring soil quality for enhanced agricultural productivity and sustainability. A two-year research (on the Dalibor Jurina familly farm in Veliki Zdenci, Bjelovar-Bilogora County) was conducted to test real fallow and green fallow on the improvement of the soil quality. Experiment is conducted in random block layout with four treatments (I. black fallow ; II. Black fallow + green manure ; III. Crops (2021-corn & 2022-soybean) + green manure ; IV. crops (2021-corn & 2022-soybean) without green manure on plots of 10 x 35 m in four repetitions on Pseudogley on the plain in semi-humid conditions. Results confirmed that green manure affects changes in the soil reaction, the stability of structural aggregates, and C/N ratio. Soil compaction is reduced in green manure plots over a period of two years (autumn 2020 - autumn 2022). Moreover, there is no correlation between green manure and maize yield in the first year of the study. Results reveal that the maize yield was lower in the treatment where green manure was applied. In the second year of the study, the yield of soybean was higher in the treatment with green manure. It is necessary to continue research in order to determine changes in physical and chemical properties and to observe the influence of green manure on them, as well as on the yield of cultivated crops.

Agriculture can contribute signifi cantly to climate change mitigation through biological carbon sequestration, i.e., the storage of atmospheric carbon in the plant pool through the process of photosynthesis. The objective of this study is to determine the carbon (C) and nitrogen (N) content in above- and below-ground biomass, as well as C and N balance of soybean biomass. Destructive harvest of aboveground (grain, stems, leaves, stubble) and belowground (root system) biomass of soybean (Glycine max L.) was conducted in Šašinovec, Croatia (45°50’ N ; 16°11’ E ; 120 m a.s.l.) in 2019. The C and N balance represents the diff erence between C and N gains (stems+leaves+stalks+root biomass) and losses (grain biomass) in the agroecosystem. The total dry matter yield is 16.53 t ha-1 and is composed of 23.7% grain, 48.6% stem, 20.8% leaf, 2.1% stubble and 4.9% root biomass. The average C and N content ranged from 25-55% and 0.5-7%, respectively. The total C balance is positive and is 3, 38 t ha-1, with total gains of 5, 52 t ha- 1 and total losses of 2, 14 t ha-1. The total N balance is negative and is -0.13 t ha-1, with total gains of 0.13 t ha-1 and total losses of 0.26 t ha-1. The negative N balance indicates that soybean biomass negatively aff ects soil quality and results in N losses from the agroecosystem, while the positive C balance indicates that soybean biomass can contribute to climate change mitigation through biological carbon sequestration under the studied agroecological conditions.

The need to reduce the environmental impact of agricultural activities and to control soil structure degradation is one of the main aims of conservation land management. We show here the experiments and measurements we conduct within the SEDCRO project to help the scientists, farmers and policy makers in the understanding of the soil and hydrologic processes. The main factors that determine soil losses and runoff was assessed: slope, soil management, vegetation cover, organic matter, infiltration, soil moisture, soil water repellency, and structural stability. Project outcome reveal that several strategies should have to been developed to reduce the most important degradation problem - soil erosion: 1) terracing on steep slopes, 2) use of cover crops, 3) mulching and 4) no-tillage. Inappropriate practices (wheeling, agrochemicals, tillage) accelerates soil compaction, runoff and soil erosion in Croatian pedosphere. This also increase risk of surface water pollution. Complex of agricultural, social, economic and environmental reasons are generally the driving force for unsustainable soil management practices in Croatian agricultural land. SEDCRO project fill the gaps in several missing things: 1) a lack of research of proportion of soil erosion in Croatia ; 2) lack of knowledge of driving forces of erosion - like aggregate stability, effect of slope, and physical and chemical properties which control the aggregate breakdown ; in contrast to: a) different soil types b) land use, c) topography and d) rainfall intensity. The mechanisms, processes, rates and control of soil erosion have been scientifically studied for more than four years to convey new findings and discuss new challenges. In Croatia, such research trough SEDRCO project provides more than 19 scientific papers, 1 book and 1 book chapter, while from 3 PhD candidates that work on project one become doctor and other two will be in 2023. Outcome of the SEDCRO project will help to improve management of agricultural soils under more pronounced every-day climatic extremes in Croatian environment. Research of soil erosion and degradation on Croatian provide deep insight for understanding the processes of soil degradation and extent of degradation damage for future change of legal policy. Present subject of research helps to discover most endanger soils and unsustainable land use practices, which help to conserve soil and water for future generations.

In late 2020, the first weighing lysimeters in Croatia were installed at the SUPREHILL vadose zone observatory, at the top and bottom of the hillslope. The use of undisturbed weighable lysimeters is commonly used to measure water and solute fluxes at the profile scale, which can also be representative at the field scale. The lysimeters are monolithically filled, equipped with a pressure-controlled lower boundary in order to mimic field dynamics (upward and downward fluxes), and are weighable so that high-precision calculations of hydraulic fluxes (i.e. rainfall, drainage, evapotranspiration, or dew) are possible. The first glance at the 2021 data shows differences between the top and bottom of the hillslope in observed evapotranspiration, while lesser differences are observed in measured precipitation using the system. As a result of the position on the hillslope, different behavior of the soil-water potential that serves as a reference value for establishing equilibrium between the field and lysimeters is observed. Along with the first data from the observatory, the presented material includes installation methodology, system specifications, and description of the feedback control of the lower hydraulic boundary condition with its main components.

Globalna urbanizacija i gubitak poljoprivrednih i šumarskih površina, ukazuju na važnost promatranja načina korištenja tla u urbanim sredinama. U ovom istraživanju prikazati ćemo utjecaj šumske sastojine (FOR), zapuštene poljoprivredne površine (ACROP), oranice (CROP), livade (MEAD) i voćnjaka (ORCH) na fi zikalna svojstva (trenutačna vlažnost tla – SWC ; kapacitet tla za vodu – WHC ; volumna gustoća tla – BD) u Gradu Zagrebu. Sa svih lokacija uzeti su uzorci sa dubine 0-10 cm (8 po tretmanu ; 40 ukupno), tijekom proljeća i jeseni 2021. godine. Način korištenja zemljišta značajno je utjecao (p < 0.05) na sve parametre. Prema dobivenim rezultatima u proljetnom mjerenju BD bilježi značajno niže vrijednosti kod ACROP i MEAD, nego kod FOR, CROP i ORCH. U jesenskom mjerenju FOR je značajno niži od ACROP, CROP, MEAD i ORCH. Kapacitet tla za vodu bilježi kod FOR značajno veću vrijednost od ACROP, ali i značajno manju od MEAD, u jesenskom rarzdoblju FOR, CROP i MEAD su značajno niži od ACROP i ORCH. Kod trenutačne vlažnosti FOR i ORCH su značajno niži od MEAD, ali veći u odnosu na ACROP i CROP, u jesenskom mjerenju ORCH je značajno veći u odnosu na preostale načine korištenja. Način korištenja zemljišta, odnosno izostanak primjena agrotehničkih zahvata u FOR, MEAD i ACROP uzrok je povoljnih vrijednosti fi zikalnih svojstava. Tretmani sa intenzivnim i učestalim agrotehničkim zahvatim (CROP i ORCH), zahtjevaju kontinuirani monitoring, kako bi se spriječila degradacija tla.

Požari su dio prirodne dinamike mediteranskog ekosustava te mogu uzrokovati trajne promjene i degradaciju tala. Glavna svrha istraživanja bila je primijeniti spektralne podatke dobivene iz satelitskih snimaka za praćenje utjecaja požara na sadržaj organske tvari (OT) tla. Istraživanje je provedeno u Zadarskoj županiji na približno 13.5 ha požarom zahvaćene šume Quercus pubescens Willd. i Juniperus communis L. Ukupno 120 uzoraka tla (0-5 cm dubine) prikupljeno je dva dana nakon požara. Dvije satelitske snimke sa Sentinel-2 satelita preuzete su s čvorišta otvorenog pristupa Europske svemirske agencije (ESA) prema najbližim datumima terenskog uzorkovanja, a svaka sadrži osam vidljivo-blisko infracrvena (VIS-NIR) i dva kratkovalna infracrvena (SWIR) pojasa koji su izdvojeni iz piksela tla. Za procjenu sadržaja OT iz spektralnih podataka uspoređeni su linearni model parcijalne regresije najmanjih kvadrata (PLSR) i nelinearni model umjetnih neuronskih mreža (ANN). Točnost modela određena je pomoću korijena prosječne kvadratne pogreške predviđanja (RMSEp) i omjera performansi i odstupanja (RPD). Oba modela pokazala su niske RMSEp i visoke RPD vrijednosti koje ukazuju na vrlo dobra predviđanja sadržaja OT tla. Daljinska istraživanja pokazala su velik potencijal u analizi i praćenju OT tla u post-požarnom razdoblju.

Surface and subsurface water runoff can be predominant hydrological flux components in sloped arable land. While various methods are used for the quantification of hillslope fluxes, combining methods is necessary in order to perform proper analysis. The aim of the research was to investigate (sub)surface water runoff at the SUPREHILL observatory (during 2021) and to validate the sensor and instrument data. Field equipment included self-constructed soil-water collection instruments for capturing surface and subsurface runoff, installed at soil surface and at 60 cm depth, respectively. The instruments were accompanied by time-domain reflectometry (TDR) sensors installed at 20 and 60 cm depth. For the determination of terrain sloping, aerial imagery acquired with an unmanned aerial vehicle (UAV) was used. The imagery was processed using Agisoft Metashape to generate dense surface from motion (SfM) point clouds. The process resulted with a digital orthophoto map (DOM), digital surface model (DSM), and a virtual 3D model of the vineyard. The first results show that sensor data backs up the results from soil-water collection instruments and also confirms that the combination of methods is crucial for unveiling the runoff processes. Furthermore, the sensor data and soil- water monitoring results suggest that surface and subsurface flow play a relevant part in the hillslope soil-water dynamics.

Wildfires have provided regulatory services in many terrestrial ecosystems throughout history. Low severity fires promote rapid vegetation recovery, and generally have a neutral impact on most soil properties, while high severity fires have adverse effects on many soil properties that can cause permanent environmental degradation. The objective of this study was to determine the effect of wildfire severity (HS-high severity ; MS-medium severity ; C-unburned), vegetation type (Q- Quercus p. and J-Juniperus c.) and time-since-fire (3 days, 3, 6, 12, 18 and 24 months) on soil texture in calcocambisol. Soil sampling (0-5 cm, N=180) was carried out on 15 ha of fire affected mixed Quercus pubescens Willd. and Juniperus communis L. forest in Zadar County (Croatia). Soil texture was determined via the pipette-method as silty loam. The results showed that fire severity and vegetation type had significant impact on soil sand, silt, and clay fractions, while their variability over time was not significant (p

U kopnenim ekosustavima, tla mogu djelovati kao ponori ili izvori ugljika, ovisno o načinu gospodarenja i klimatskim uvjetima. Disanje tla predstavlja jedan od glavnih izvora ugljikovog dioksida (CO2). Stupanj razvoja CO2 iz tla ovisi o mnogim čimbenicima, a jedan od njih su agroklimatski elementi. Da bi se utvrdio utjecaj temperature i vlage tla na stupanj razvoja CO2 iz tla, praćeno je disanje tla odnosno emisija C-CO2 iz tla u kontinentalnom dijelu Hrvatske u blizini grada Zagreba tijekom 2019. godine. Emisija C-CO2 iz tla mjerena je metodom zatvorenih statičkih komora u vegetaciji soje (Glycine max L.). Disanje tla povećavalo se s razvojem usjeva, i bilo je najviše u srpnju a najmanje u listopadu prije žetve soje. Disanje tla kretalo se u rasponu od 4, 5- 31, 2 kg ha-1 dan-1, s godišnjim prosjekom od 15 kg ha-1 dan-1. Temperatura i vlaga tla kretale su se u rasponu od 7, 7-37, 1 °C, odnosno 17, 3- 39, 8 %, s godišnjim prosjekom od 19, 6 °C, odnosno 29, 1 %. Vlaga tla imala je veći utjecaj na disanje tla u odnosu na temperaturu tla. S obzirom da je disanje tla pod utjecajem složenih interakcija nekoliko čimbenika ; preporuča se daljnje proširenje istraživanja i na druge kontrolirajuće čimbenike.

Environmentally sustainable agricultural practices are key for preserving soil physical quality and providing stabile grain yields. The interacted impact of the tillage and organic fertilisation on soil bulk density (BD), penetration resistance (PR), and grain yields is not well understood in a Mediterranean climate. A study was carried out on Anthrosols in a Mediterranean Croatia (Raša valley) during 2017- 2018 period. In split-plot design in three repetitions main plots was conventional tillage (CT), minimum tillage (MT) and reduced tillage (RT). Subplots were treatments with 600 kg ha-1 organic fertiliser (OF), 30 t ha-1 (FMY30) and 15 t ha-1 (FYM15) of farmyard manure. During 2017, MT increased (p < 0.05) BD in the 10–20 cm depth in relation to RT and CT. During 2018 MT increased BD on 0-10 cm and 10-20 cm depths in addition to RT and CT. Reduced tillage treatment had a significantly lower PR comparing to MT and CT in 2017 and significantly lower than MT in 2018. In 2017, CT had significantly lower oat yields compared to RT. During 2018 barley grain yields was significantly the highest under the CT, while under MT was significantly the lowest. Oat grain yields were significantly lower under the PE treatment compared to FMY30 and FMY15 treatments in 2017. During 2017 and 2018 farmyard manure decreased (p < 0.05) BD in addition to OF. Reduced tillage treatments with addition of FMY30 can therefore be considered in Mediterranean environment as proper management strategy for desirable physical conditions and stabile grain yields.

Wildfires are a common occurrence in the Mediterranean and geostatistical methods offer the opportunity to effectively monitor their impacts on various soil properties. The goal of this study was to compare Inverse distance weighting with the power of one and two, Ordinary kriging and Empirical Bayesian kriging to determine the most accurate interpolation method for mapping the soil pH, electrical conductivity and organic matter content after a wildfire in Mediterranean Croatia. The results suggested that Ordinary kriging would be the optimal choice for soil pH, while Empirical Bayesian kriging proved more accurate for soil electrical conductivity and organic matter content.