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Soil sampling is the first step in generating field-specific information on which to base agricultural input decisions. The objective of the study was to evaluate spatial and temporal variability of soil pH, plant available phosphorus (P2O5) and potassium (K2O) content under variable mineral nitrogen (N) fertilization. The research was conducted on the experimental field within hydro-ameliorated cropland in the Western Pannonia subregion of Croatia (45°33’N, 16°31’E). Grid soil sampling (15x15 m ; n=200) was carried out with semi-automatic circular tractor soil probe at 30 cm depth after winter wheat harvest in 2010 and 2016 covering ten fertilization treatments (0-300 kg N ha-1). A sequence of spatial changes in soil properties was influenced by differences in N rates, liming, field drainage and specific terrain features, although similar spatial response was apparent for both investigated years. A two-way ANOVA revealed that only soil pH values significantly differed among two years (p

Nowadays, when the negative impact of nitrogen fertilization is recognized, requisites are arising to determine the actual contribution of specific agricultural practices on environment degradation. Isotope analyses are imposing as key techniques for confirmation of nitrogen origin in soil and agricultural impact on ecological footprint of nitrogen on environment. Main objectives of this research were: (a) to determine soil δ15N isotope content regarding the variable doses of nitrogen fertilization and soil depth ; (b) to determine δ15N isotopic signature in applied commercial nitrogen fertilizers. Research was based on 12 soil samples and 9 fertilizers [urea, granular and piled LAN (limestone ammonium nitrate) and six NPK fertilizer formulations]. Soil samples were collected from a stationary field experiment in 2018 located in central part of Croatia after 22 years of application variable nitrogen doses (0, 100, 200 and 300 kg N/ha) on three depths (0-30, 30-50 and 50-80 cm). Analyses were performed in 2021 in two replications and δ15N isotopes in soil and fertilizers were determined by the EA-IRMS method. The results reveal that variability of the δ15N isotope content in soil (+5.1 ‰ to +7.7 ‰) indicates the organic origin of nitrogen in the soil despite the long-term application of mineral nitrogen fertilizers. As a confirmation of this allegation the range of δ15N values in the applied nitrogen fertilizers was from -0.96 ‰ in piled LAN up to +3.26 ‰ in NPK 7-20-30, implying that observed fertilizers were produced by processes of "industrial" fixation of atmospheric nitrogen and they did not leave a mark on the total nitrogen in the soil.

To better understand the impact of conventional agricultural practices on soil and water resources, two main objectives were established in this study: to measure nitrate (NO3-) and sulphate (SO4 2-) concentrations in lysimeters and drainpipes leachates in response to different nitrogen fertilization levels and soil amendments and to identify organic contaminants that could have originated from the long-term use of agrochemicals in historically intensive agricultural area in Croatia. During the two-year study period leachate samples were collected from lysimeters and drainpipes. Research results indicate NO3- content in both lysimeters and drainpipes increased with rising doses of N fertilizer. The highest concentration of SO4 2- was recorded in the treatment with added phosphogypsum, while in all other treatments the concentrations were low. Over 40% of the 287 target substances were detected at least once during the two-year study period but only two substances (IPC/propham and carbosulfan) were found to have concentrations above 0.5 µg/L. Additionally, three priority substances were continuously present in the leachate samples: atrazine, simazine and isoproturon., Da bi se bolje razumio utjecaj konvencionalne poljoprivredne prakse na tlo i vodne resurse, u ovom radu uspostavljena su dva glavna cilja: mjerenje koncentracija nitrata (NO3-) i sulfata (SO4 2-) u lizimetarskim i drenskim procjednim vodama kao odgovor na gnojidbu različitim razinama dušika te poboljšivača tla te identificirati organske onečišćivače čije je moguće izvorište u dugotrajnoj uporabi pesticida na povijesno intenzivno poljoprivrednom području u Hrvatskoj. Tijekom dvogodišnjeg razdoblja uzorci procjednih voda prikupljani su iz lizimetara i drenskih cijevi. Rezultati istraživanja pokazuju da se sadržaj NO3- u lizimetrima i u drenskim cijevima povećavao s porastom doza N gnojiva. Najveća koncentracija SO4 2- zabilježena je u tretmanu s dodanim fosfogipsom, dok su u svim ostalim tretmanima koncentracije bile niske. Preko 40% od 287 ciljnih tvari otkriveno je barem jednom tijekom dvogodišnjeg razdoblja ispitivanja, ali utvrđeno je da su samo dvije tvari (IPC/propham i carbosulfan) imale koncentracije iznad 0,5 µg/L. Uz to, tri prioritetne tvari bile su kontinuirano prisutne u uzorcima procjednih voda: atrazin, simazin i izoproturon.

Knowledge of nitrogen fertilization contribution to the soil organic carbon (SOC) variability is very important in order to preserve the climate-regulating role of soil through measures of sustainable soil management. The aim of this research was to determine SOC distribution up to 2 meters in drained distric Stagnosol according to different nitrogen fertilization levels. SOC content was determined in 128 soil samples which were sampled from experimental plot (central Croatia, Potok location) after 10 years of fertilization (0, 100, 200, 300 kg N/ha/per year) on eight depths (each 25 cm up to 2 m) in four replications. SOC was determined indirectly by calculation from total soil carbon and carbonate content. Results reveal that long term application of 200 and 300 kg N/ha significantly contribute to SOC enrich especially in surface soil layer. Along with those findings, SOC content was significantly reduced through soil profile on all treatments. The largest SOC stock (615 t/ha) was determined on treatment with 200 kg N/ha applied

Knowledge and understanding of carbon and nitrogen biogeochemical cycles in agroecosystems are crucial for a global sustainable management and development. Nitrogen and carbon forms and compounds cycle between pedosphere, hydrosphere and atmosphere. This includes a very wide range of complex reactions which are influenced by many factors. From abiotic, like temperature and sunlight, through biotic (microorganisms) up to anthropogenic, including different agricultural practices (fertilization, tillage, drainage). Nitrogen oxides (NxOy) ammonia (NH3), carbon oxide (CO2) and methane (CH4) emissions from the agricultural sector contribute with more than 10 % in total GHGs emissions. Some of them are primary pollutants (NOx, NH3) or directly affect the greenhouse effect (N2O, CH4, CO2) and some of them contribute in producing secondary pollutants (NOx, NH3) and GHG like O3 or N2O. The methods used for air quality (NxOy) measurement are assigned to 4 categories: (1) passive sampler methods ; (2) active methods ; (3) automatic methods and (4) remote sensing methods. All of them have advantages and disadvantages. This research, which was conducted in a conventional agroecosystem under triticale vegetation, in a field experiment in Croatia, was based on measurement of nitrogen oxide emissions, by using a method with passive samplers and static chambers which we have developed. The aim of the study was to determine the suitability of the selected method for N-NO2 concentration measurement. It was presumed that, if measured concentration was higher than the limit of detection (LOD), it was possible to determine the potential impact of mineral fertilization on the N-NO2 emission (two treatments with 0 and 300 kg N/ha). Also, the intention was to compare N-NO2 emission between two sets of measurements in phenophases (tillering and jointing) of triticale. The research had shown that the used method was suitable for N-NO2 concentration measurement (measured concentrations were above LOD). Measured daily values of N-NO2 emission ranged from 1.66 to 7.18 mg/ha per day, depending on phenophase and treatment. Statistically significant differences in N-NO2 emission between two monitored treatments (300 kg N and 0 kg N) were not observed, as well as between two investigated phenophases. Soil temperature in March 2014 (22.3 °C) was significantly higher than in April 2014 (10.9 °C). Average cumulative annual flux was 1.15 g/ha per year and 1.55 g/ha per year, respectively, depending on the treatment.

Carbon dioxide (CO2) emissions from terrestrial ecosystems represent one of the most important contributors to climate change. It is considered that most of the carbon released to the atmosphere is originated through agricultural activities that mainly increased since the industrial revolution where irresponsible land management often leads to soil carbon loss and increased carbon dioxide emissions to the atmosphere. Likewise, agricultural management practices that include changing the soil environment affect soil CO2 flux. The objective of this study was to determine the influence of different fertilization in soybean agro ecosystem on CO2 respiration. The field experiment with four different fertilization treatments was set up in central part of Croatia (N 45° 33' 21.42'', E 16° 31' 44.62'') on deep, distric pseudogley (Stagnosol). It contains four different fertilization treatments as follows: (I) control treatment – no fertilization, (II) organic fertilization – 40 t ha−1 of solid farmyard mixed manure + P + K, (III) mineral fertilization – 300 kg ha−1 N + P + K and (IV) black fallow – no vegetation. The cover crop at the experimental field in the investigated year (2018) was soybean (Glycine max L.– Tena variety) which was sown on 27th April 2018 and harvested on 26th September 2018. The experimental plot is characterized by continental climate. In the studied year (2018) mean amount of precipitation was 824.5 mm with mean temperature of 12.7 °C. The measurements of soil CO2 concentrations and soil properties were conducted eight times during the vegetation year (January, March, April, May, June, July, August and September) in three repetitions on each treatment. The soil CO2 concentrations were measured by a closed static chamber method with incubation time of 30 minutes. After 30 minutes, the soil CO2 concentrations were measured with portable infrared CO2 detector (GasAlerMicro5 IR, 2011). The soil carbon dioxide flux was expressed as kg C-CO2 per ha per day. At the beginning and the end of each measurement, air temperature and relative air humidity were measured with Testo 610 (2011) and air pressure with Testo 511 (2011). Soil properties (temperature and moisture) were measured with IMKO HD2 – probe Trime, Pico64, 2011 at 10 cm depth in the vicinity of the chambers in three replications. Depending on fertilization treatment, mean annual C-CO2 flux ranged from 7.7 kg ha-1 day-1 on black fallow to 16.7 kg ha-1 day-1 on treatment with mineral fertilization and were significantly different (SAS 9.1 p

U elemente platinske skupine (eng. platinum group of elements- PGE) spadaju platina (Pt), paladij (Pd) i rodij (Rh). Upotreba tih elemenata danas u svijetu je velika i široka, od elektronike preko stomatologije, draguljarstva i medicine, sve do automobilske industrije. Automobilski katalizatori imaju važnu ulogu u radu ispušnih sustava, smanjujući emisije plinovitih onečišćujućih tvari. Međutim, vrući ispušni plinovi koji prolaze kroz automobilski katalizator uzrokuju emisije PGE u okoliš i mogu predstavljati potencijalni rizik za zdravlje ljudi jer su alergeni. Do ovog istraživanja na Institutu za medicinska istraživanja i medicinu rada (IMI) razrađena je metoda za određivanje koncentracija PGE u lebdećim česticama u zraku, međutim ne i u biljci i tlu. Za sada u našoj zemlji ne postoje podaci o razinama navedenih metala u drugim sastavnicama okoliša (vegetacija i tlo) osim u zraku. Ciljevi ovog istraživanja bili su: (i) razraditi i prilagoditi metodu za određivanje PGE u biljci i tlu ; (ii) u blizini lokacija (3 u Zagrebu) na kojima se već sakupljaju uzorci lebdećih čestica u zraku prikupiti uzorke ostalih sastavnica okoliša (tla i biljke) te odrediti koncentracije PGE u njima ; (iii) utvrditi sezonske (proljeće i jesen) i prostorne (3 urbane lokacije) razlike u koncentracijama PGE u pojedinim sastavnicama okoliša, te utvrditi povezanost između njih (tlo, biljka, zrak). Uzorci tla i vegetacije sakupljani su na tri lokacije u različito onečišćenim dijelovima grada Zagreba. Uzorci vegetacije i tla sakupljani su tijekom dvije godine (2018.-2019.) dva puta godišnje (u proljeće i jesen) ; po dva uzorka biljnog materijala (Plantago Lanceolata L. i Dactylis glomerata L.) i po dva uzorka tla (2 dubine: 0-5 cm i 5- 10 cm) sa svake lokacije. Tjedni uzorci lebdećih čestica aerodinamičkog promjera manjeg od 10 µm (frakcija PM10 ) sakupljani su tijekom cijele godine. Priprava i analiza uzoraka na PGE provodila se po metodi koja se razradila u sklopu ovog istraživanja, a sastojala se od priprave uzoraka razgradnjom u kiselini uz mikrovalove pri povišenoj temperaturi i tlaku te analize spektrometrijom masa uz induktivno spregnutu plazmu (ICP-MS). Tlo se analiziralo i na osnovne agrokemijske analize bitne za razumijevanje mobilnosti i biodostupnosti PGE (tekstura, pH, EC, OT, (P i K)AL, CEC, zamjenjivi Na+, K+, Ca2+ i Mg2+, vodotopivi anioni i kationi, CaCO3, TN, TS, te elementarni sastav od Mg do U). Rezultati pokazuju značajno veće koncentracije Pd u tlu, zraku i vegetaciji od Rh i Pt. Plantago Lanceolata L. pokazuje veći sadržaj PGE od Dactylis glomerata L. Koncentracije u tlu i zraku kreću se u nizu Pt > Rh > Pd, a u biljnom materijalu Rh > Pt > Pd.

As a source of greenhouse gas emissions, the agricultural sector directly affects the global problem of climate change. A research study was conducted in Western Pannonian sub-region of Croatia to measure soil respiration and its seasonal variability influenced by vegetation presence (maize - Zea mays L.). Soil C-CO2 flux was measured 14 times during the investigated period in a field experiment with 4 different fertilization treatments. Average daily C-CO2 flux was the highest in June 2017 (38.2 kg ha-1 day-1) and the lowest in November 2017 (0.76 kg ha-1 day-1). The results imply that season and vegetation presence has a significant effect on soil respiration rates.

The anthropogenic emission of greenhouse gases including carbon dioxide, methane, and nitrous oxide is bringing about major changes to the global environment. Although most of the anthropogenic emissions originate from industrial processes, agriculture is responsible for a significant portion of the greenhouse gases produced by humans worldwide. The impact of agriculture has become a key issue, considering that the main greenhouse gases are those related to carbon and nitrogen global cycles. This paper presents a review of the scientific literature meant to provide the impact of human management through fertilizers use on CO2, CH4, and N2O emissions. The influence of organic and mineral fertilization on greenhouse gas emissions is analyzed, and usage of organic amendments showed a wise potential for protecting the environment and to mitigate greenhouse gas emissions.

Crop type and meteorological parameters play an important role in the temporal variation of soil respiration, which varies significantly among plant biomass and climate conditions. The influence of growing an energy crop (Giant Miscanthus) and arable crops (winter wheat, maize), as well as meteorological parameters on soil respiration is represented in this paper. Soil respiration and meteorological parameters were studied from April 2013 until October 2013 in the continental part of Croatia (Bistra, Daruvar, Potok). Soil CO2 concentrations were measured by the in situ closed static chamber method. Soil respiration had different seasonal patterns within crops with average monthly soil respiration rates ranging from 22.7-32.1 kg C- CO2 ha-1day-1 for Giant Miscanthus, 25.6-41.8 g C-CO2 ha-1day-1 for wheat and 8.0-22.1 kg C- CO2 ha-1day-1 for maize, respectively. Average amount of carbon emitted to the atmosphere by soil respiration in one year is significantly lower under maize (5.95 t ha-1), compared to wheat (11.32 t ha-1) and Giant Miscanthus (10.51 t ha-1). Depending on the crop type, 4- 19% of soil respiration depends on air temperature and 2-53% on relative air humidity. Further research on other controlling factors of soil respiration is recommended.

Calibration models based on multiple linear regression (MLR), partial least squares regression (PLSR) and artificial neural networks (ANN) were developed in order to predict leaf nitrogen (N) content in soybean utilizing hyperspectral reflectance data. Research was conducted on experimental field with 9 treatments of mineral N fertilization (0-300 kg N ha-1). Total of 180 soybean leaf samples in the beginning of flowering (R1) were scanned using field spectroradiometer (350-1050 nm). The highest correlations with soybean N content were found in red edge to NIR region. Validation models revealed strong to very strong correlation between predicted and measured values (MLR: R2=0.39 ; PLSR: R2=0.68 ; ANN: R2=0.70).

The links between the richness of the natural environment and farming practices are very old and complex. Needs for food and feed production are always being very important, and today, special emphasis is on its quality. Farming and nature influence each other. Inappropriate agricultural practices and land use can have an adverse impact on natural resources, like soil, water and air pollution, fragmentation of habitats & loss of wildlife. In the same time, agriculture is directly influenced by the nature. For example, regarding the climate change, agriculture is cause but in the same time and the victim of it. In Croatia in 21st century drought caused 51 % of total agricultural damage, hail 16 % and floods 12 % and more than half of the money that Croatia invested through direct payments (CAP) has been “eaten” by weather conditions. European Union as a leader in environment protection within CAP develops two mechanisms (direct and voluntary payments) and defines priority areas for agriculture: soil and water management, biodiversity preservation, landscape and climate change. Agri-environmental indicators (AEIs) are useful tool for analyzing the relationship between agriculture and the environment and identifying trends in this evolving interaction. To provide information on the state of the environment in agriculture and to understand and monitor the linkages between agricultural practices and their effects on environment, different set of indicators are identified: OECD and UN-FAO identified 62 AEIs, EU-EC-EEA 28 AEIs using DPSIR framework and methodology. Some of them will be explain and discussed.

Interakcija poljoprivredne prakse i okoliša vrlo je kompleksna. Na poljoprivrednim površinama uobičajeno se, osim obrade tla, primjenjuju pesticidi, mineralna i/ili organska gnojiva. Stoga, ovisno o nizu čimbenika, postoji mogućnost njihova dospijeća u površinske i podzemne vodne resurse. U suradnji s Hrvatskim vodama 2014. realiziran je projekt „Utjecaj poljoprivrede na onečišćene površinskih i podzemnih voda u Republici Hrvatskoj“ (akronima SAGRA od scientia agri aqua). Podaci dobiveni ovim projektom (način korištenja zemljišta u RH, analiza potrošnje sredstava za zaštitu bilja, procjena pritisaka dušika i fosfora iz mineralnog i organskog gnojiva pritisaka iz stočarske proizvodnje i dr.) svojevrsna su osnova za detaljniju analizu i dopunu podataka potrebnih za procjenu opterećenja voda iz poljoprivrede. Sukladno Nitratnoj direktivi u RH potrebno je provoditi monitoring voda na 239 lokacija (92 postojeće i 147 novih). Lokacije monitoringa trebaju biti locirane na ranjivim područjima, odnosno lokacijama gdje se odvija najveći pritisak iz poljoprivrede. U okviru prethodnog (SAGRA) i ovog projekta, stručnjaci fitomedicinari (Klara Barić, Renata Bažok i Ana Pintar) obavljaju analizu ukupne potrošnje SZB i temeljem načina korištenja poljoprivrednog zemljišta i stručne procjene o procjeni primjene SZB u pojedinoj kulturi, utvrdit će pritisak SZB na vode. Posebno će biti istaknute aktivne tvari iz pojedine skupine pesticida koje čine najveći dio u potrošnji.

The application of mobile devices (smartphones, tablets, etc.) to the agriculture sector has been greatly increased in the last decade. The ICT technologies have become an essential part of any business. Using Internet on mobile devices can prove to be essential in agriculture production. A new generation of mobile devices are lower in price and more user-friendly. This paper provides an overview of software applications that are created in Croatia and are mostly in the Croatian language. They are divided into groups of agriculture related applications; agriculture management information apps; agriculture information resource apps; agriculture calculator apps; agriculture news apps, weather apps. The research shows the agri-apps are still in its infancy and we can say that it reflects the state of agriculture in Croatia. Apps are a promising solution for farmers enabling them quick and trustworthy access to information. At the moment, further analyses are needed for scientific proof and improvement of a product., Primjena mobilnih uređaja (smartphona, tableta, itd.) u sektoru poljoprivrede se uvelike povećala u posljednjih deset godina. Informacijskokomunikacijske tehnologije (ICT) su postale važan dio u svakom poslu.Korištenje Interneta na mobilnim uređajima može se pokazati kao ključno u donošenju odluka u poljoprivrednoj proizvodnji. Nova generacija mobilnih uređaja postiže niže cijene i više je "user-friendly". U radu se daje pregled softverskih aplikacija na hrvatskom jeziku načinjenih u Hrvatskoj. One su podijeljene u skupine poljoprivrednih aplikacija; aplikacije za upravljanje poljoprivrednom proizvodnjom; aplikacije za dokumentiranje u poljoprivredi; aplikacije za poljoprivredne kalkulacije; vijesti iz poljoprivrede; vremenske prognoze; informacije iz državnih poljoprivrednih institucija. Istraživanje pokazuje da su poljoprivredne aplikacije još uvijek u povojima i možemo reći da one odražavaju stanje poljoprivrede u Hrvatskoj. Aplikacije su obećavajuće rješenje za poljoprivrednike omogućujući im brz i pouzdan pristup informacijama. U ovom trenutku, potrebne su daljnje analize kako bi se znanstveno dokazala pouzdanost dostupnih aplikacija

Brojna recentna istraživanja potvrđuju postupni porast prosječnih dnevnih temperatura u zadnjih nekoliko decenija te povećanu učestalost ekstremnih godina u smislu količine i rasporeda oborine, a brojne simulacije upućuju da će se ovaj trend nastaviti i u narednim decenijama. Zbog velikih površina na kojima se uzgajaju i dominantnom uzgoju bez navodnjavanja, proizvodnji kukuruza i soje u Hrvatskoj prijete snižavanje prosječnih uroda i velike štete u ekstremnim godinama, posebno onim s obilježjima suše. Među inim agrotehničkim mjerama kojima se mogu ublažiti utjecaji suše, svakako najekonomičniji i najpoželjniji je razvoj novih sorata s povećanom tolerancijom na sušu. U cilju procjene adaptabilnosti i tolerantnosti na sušu tijekom 2017. godine proveden je poljski pokus na 19 lokacija širom RH u kojemu je u mikropokusima testirano po 32 komercijalna genotipa, a na svakoj pokusnoj lokaciji prikupljani su od sjetve pa do žetve u satnom režimu sljedeći meteorološki podaci: temperatura i vlaga zraka, količina oborina, jačina, brzina i smjer vjetra, te vlažnost tla na dubini od 30 cm na dnevnoj bazi. U ovom radu detaljno prikazujemo vremenske prilike utvrđene izravno u usjevima za 8 lokacija u Slavoniji, 6 u zapadnoj Hrvatskoj, 3 u Istri i 2 u Dalmaciji. U radu se analizira intenzitet i trajanje razdoblja nepovoljnih uzgojnih uvjeta u 2017. spram višegodišnjih prosjeka, kao i razlike među lokacijama i posljedice na prosječne prinose kukuruza i soje.

Na području mediteranskog dijela Hrvatske prevladavaju tla niske plodnosti. Izraženi klimatski ekstremi zahtjevaju prilogodbu u načinu gospodarenja tlima. Nadalje, nepravilna agrotehnika i nedostatak organskih gnojiva često dovodi do degradacije tala uz potencijalno onečišćenje okoliša. Navedena tla većinom su slabo alkalne reakcije, slabo humozna, siromašna hranivima uz loša fizikalna svojstva. Istraživanje se provodi na stacionarnom pokusnom polju (Istarska županija, dolina Raše, OPG Chiavalon). Pokus je postavljen po split-plot dizajnu u tri ponavljanja. Način obrade je glavni faktor pokusa u usporedbi s organskom gnojidbom (CT- diskosni plug do 30 cm, tanjurača, rotodrljača, sjetvospremač ; RT1 – plitka obrada, sjetvospremač ; RT2 – obrada u jednom prohodu kombiniranim oruđem), te tri stepenice pod- faktora „Gnojidba“ (GKG – gnojidba komercijalnim organskim gnojivima, GKSG15 – gnojidba s 15 t/ha domaćim krutim stajskim gnojem i GKSG30 – gnojidba s 30 t/ha domaćim krutim stajskim gnojem). Dobiveni rezultati u sezoni 2016/2017 otkrivaju da je tlu u mjesto istraživanja ujednačeno po kemijskim svojstvima, što ide u prilog prema postavljenim tretmanima pokusa. Vidljivo je da je tlo alkalno s reakcijom u KCl-u od 8, 03 do 8, 17, a u vodi s 9, 05 do 9, 26. Elektrovodljivost tla kretala se je u uskim granicama od 105, 9 do 107, 8 dScm-1. Tlo je slabo (2, 4 %) do dosta humozno (3, 8 %), ovisno o tretmanu. Istraživana tla su u prosjeku vrlo bogato opskrbljeno kalijem (od 30, 7 do 39 mg/100 g tla), ali imaju nizak sadržaj biljci pristupačnog fosfora (od 1, 2 do 6, 1 mg/100g tla). Sadržaj dušika kreće se u prosjeku u dobroj opskrbljenosti (srednja vrijednost 0, 18 %). Provedena obrada na tretmanima značajno je utjecala na otpore tla (p0, 05). Struktura tla pokazuje zanimljive rezultate. Prema djelovanju obrade tla na prosjek težina- veličina agregata (engl. Mean weight diameter – MWD), RT2 se pokazala kao obrada koja ostavlja prosječno najveći udio strukturnih agregata (MWD 56, 61), dok je CT obrada s najmanjim prosječnim udjelom strukturnih agregata (MWD 55, 23). Slične vrijednosti dobivamo i usporedbom tradiocionalnih postotnih udjela makro, mezo i mikroagregata u uzorcima tla. Možemo napomenuti da i tu najveći postotak makroagregata (>2 mm) bilježi tlo pod RT2 obradom (91, 72 %), dok je najmanji pod RT1 (90, 04 %). Udio mezoagregata (0, 25-2 mm) najveći je pak na RT1 (9, 53 %), dok je najmanji pod RT2 (7, 80 %). Udio mikroagregata je nizak i kreće se od 0, 43 % na RT1 do 0, 52 % na CT. Gnojidba također utječe na fromiranje i veličinu strukturnih agregata. Vidljivo iz rezultata je da GKSG30 ima najveći MWD (56, 62), dok je najmanji na GKG tretmanu (55, 55). Postotak makroagregata najveći je na GKSG30 (91, 97 %), mezoagregata na GKSG15 (9, 86 %), a mikroagregata na GKG tretmanu (0, 55 %). Ovi razultati, iako dobiveni u početnim fazama pokusa, mogu navesti da gnojidba krutim stajskim gnojem povoljnije djeluje na formiranje i cementaciju agregata u odnosu na peletirana komercijalna organska gnojiva. Ipak, za konkretniju potvrdu treba sačekati uzorke strukture tla prikupljene tijekom iduće vegetacijske godine. Rezultati o emisiji CO2 u atmosferu daju posebnu vrijednost s aspekta mikrobiološke aktivnosti, zadržavanja organske tvari u tlua i očuvanju okoliša. Dobiveni rezultati pokazuju visokosignifikantne ovisnosti emisije CO2 s vlagom tla (p0, 05) u emisiji CO2. Interakcijski efekt obrade i gnojidbe ukazuje da je najmanja emisija CO2 iz tla zabilježena na tretmanu RT2 x GKG (26, 4 kg ha-1 dan-1) dok je najveća na tretmanu CT x GKSG30 (46, 4 kg ha- 1 dan-1). Vlaga u tlu je tijekom sezone 2016/2017 bila na visokom nivou, ali je ipak obrada tla pokazala značajne implikacije na konzervaciju u tlu (p0, 05), ukazuje da je tretman s krutim stajskim gnojem u količini od 30 t/ha imao najveći sadržaj vlage (32%). Temperatura tla kretala se je u prosjeku od 23, 2 °C (RT2) do 29, 3 °C (CT), odnosno od 25, 4°C (GKSG30) do 26, 2 °C na GKG. Infiltracija tla se pokazala najvećom na CT tretmanu (0, 014990 m/s), dok je najmanja na tretmanu RT1 (0, 00800 m/s). Također, gledajući gnojidbu kao faktor najmanja je na GKG (0, 006190 m/s), a najveća na GKSG30 (0, 018000 m/s). I obrada (p

Soil organic and mineral compounds can be estimated non-destructively by visible and near infrared (VNIR) diffuse reflectance spectroscopy. However, results of calibration models differ in dependence of measurement precision, spectral range, variability of soil properties and calibration methods used for prediction. The objective of research was to estimate the ability of hyperspectral VNIR spectroscopy for field-scale prediction of soil total carbon (TC %) and total nitrogen (TN %) content, soil pH, plant-available potassium (K) and phosphorus (P), in arable Stagnosols. Total of 200 soil samples taken from field experiment (soil depth: 30 cm ; sampling grid: 15x15 m ; 2016) were scanned in laboratory using portable spectroradiometer (FieldSpec®3, 350-1050 nm). Partial least squares regression (PLSR) with full cross-validation and artificial neural networks (ANN) were used to build prediction models of selected soil properties based on VNIR spectra. Strong to full correlation and low root mean squared error were obtained between predicted and measured values for the calibration and validation dataset, and both calibration methods. ANN models were more efficient in capturing the complex link between selected soil properties and soil reflectance spectra. Key spectral features and algorithms defined in this study should help to support site-specific and real-time soil survey using hyperspectral remote sensing.

Agricultural sector is one of the major source of CO2 due to increased decomposition of soil organic matter caused by disturbance various agricultural practices such as fertilization, tillage and irrigation. The objectives of this study were to determine the influence of mineral and organic fertilization in winter wheat agroecosystem on CO2 respiration and soil quality. Field experiment was conducted in Potok near Popovača, where soil type is drained lowland distric Stagnosols. Investigated period (2016) was characterized by higher annual precipitation than average (+159 mm), higher average annual temperature (+1.5 °C) and real evapotranspiration (+30 mm). Four investigated treatments were OF (organic fertilization – 40 t/ha of solid farmyard mixed manure), MF (mineral fertilization – 300 kg N/ha), C (control treatment) and BF (black fallow). Mean annual values of C-CO2 flux ranged from 7.8 kg/ha x day (BF) to 21.9 kg/ha x day (OF) and were statistically significant. Annual yield ranged from 1.12 kg/ha (C) to 7.37 t/ha (MF) and values were statistically significant (SAS 9.1: p < 0.05). Organic matter content in soil ranged from 1.39 % (C) to 2.80 % (OF). Application of organic and mineral fertilizers and calcification had influence on soil chemical characteristics and daily C-CO2 flux, but not on average annualy emissions.

Cilj istraživanja bio je razviti kalibracijske modele za sadržaj dušika u listu i prinos kukuruza na osnovi hiperspektralnih podataka dobivenih in situ te multispektralnih podataka dobivenih iz zraka s obzirom na razvojnu fazu biljke i sortu. Pokusna površina (9 varijanti mineralne gnojidbe dušikom/4 ponavljanja: 0-300 kg N ha-1) veličine 4 ha s kukuruzom u razvojnoj fazi brzog vegetativnog porasta (8-12 listova) snimljena je iz zraka multispektralnom kamerom (4 kanala) u vidljivom i blisko infracrvenom (VNIR) području spektra, dok je 180 uzoraka lista kukuruza skenirano (mreža uzorkovanja: 15×15 m) spektroradiometrom (350 1050 nm). Sadržaj ukupnog dušika u listu (n=90) određen je metodom suhog spaljivanja (HRN ISO 13878:2004), a prinos zrna nakon berbe (n=36). Značajne spektralne razlike između gnojidbenih tretmana i najviše korelacije s varijablama kukuruza utvrđene su u vidljivom dijelu spektra i „crvenom rubu“. Regresijom parcijalnih najmanjih kvadrata (PLSR) te izračunom vegetacijskog indeksa (NDVI) dobiveni su predikcijski modeli ukupnog dušika u listu kukuruza i prinosa zrna. Utvrđena je vrlo jaka korelacija (r) i niska srednja kvadratna pogreška (RMSE) između predviđenih i referentnih vrijednosti za kalibracijski, odnosno validacijski model. Ključna spektralna obilježja i algoritmi utvrđeni u ovom radu doprinijet će preciznom gospodarenju i praćenju sadržaja dušika u biljci u stvarnom vremenu te predviđanju prinosa kukuruza.

U svrhu praćenja onečišćenja procjednih voda, na dvije lokacije u I. (vodocrpilište Mala Mlaka) i III. zoni sanitarne zaštite izvorišta Mala Mlaka (poljoprivredna površina) izvršeni su radovi na ugradnji lizimetara i automatskih meteoroloških stanica sa solarnim napajanjem. Pomoću ugrađenih lizimetara sprema se voda koja se procijedi kroz tlo do dubine 50 cm. Iz mjerenja količine oborine i procijeđene vode dobivaju se podaci o isparavanju vode i promjeni količine vode u tlu. U cilju provedbe Programa mjera sanacije unutar zona sanitarne zaštite izvorišta Mala Mlaka pratila se kakvoća procjednih voda kroz uzorkovanje i analizu vode na parametre: NH4+, NO2-, NO3-, PO43-, P, Ni, Fe, Mn, Cr, Zn, Pb, Cd, As, Cu, Cr6+, Hg i atrazin. U 2017. godini zabilježeno je prosječno za obje lokacije ukupno 277 mm oborina više od višegodišnjeg prosjeka za istraživano razdoblje (rujan - prosinac). Vrijednosti sadržaja teških metala u uzorcima procjedne oborinske vode na obje lokacije vrlo su niske te daleko ispod MDK. Koncentracije atrazina u vodi iz lizimetra na obje lokacije (0.01 μg/L) daleko su ispod vrijednosti MDK, te se ne pokazuju onečišćenja koja bi uzrokovala poljoprivredna proizvodnja. Sadržaj ukupnog fosfora u procjednoj oborinskoj vodi na lokaciji I. zone kretao se u rasponu 2.20 – 7.60 mg/L, te izmjerene vrijednosti premašuju MDK, dok je sadržaj ukupnog fosfora u vodi unutar III. zone bio u rasponu 0.68 – 1.96 mg/L, te su izmjerene vrijednosti ispod granice MDK. Zaključak je da se na obje lokacije radi o organskom fosforu koji se vjerojatno isprao mineralizacijom pod utjecajem velikih količina oborine. Utvrđene koncentracije NH4+, NO2-, NO3-, PO43- odnose se na sloj ispiranja od 50 cm od površine tla i ne ugrožavaju podzemne vode na lokaciji unutar I. zone. U uzorcima vode iz lizimetra unutar III. zone zabilježene su koncentracije NO3- od 8.5 mg/L, 84.0 mg/L pa čak do 461.0 mg/L, koliko je izmjereno 28.09.2017. U tom periodu izvršena je gnojidba mineralnim i organskim gnojivima, a ekstremno visoke količine oborine potaknule su ispiranje nitratnog dušika. Vrijednosti koncentracija NO2- u vodi iz lizimetra također prate trend smanjenja od datuma primjene gnojiva (0.83 mg/L), te su u sljedeća dva uzorkovanja bile nedetektabilne. Sadržaj PO43- u procjednoj vodi bio je nedetektabilan u prva dva termina uzorkovanja, dok je krajem jeseni izmjerena koncentracija od 0.31 mg/L. Koncentracije NH4+ u vodi kretale su se od nedetektabilne u prvom terminu uzorkovanja do 0.63 mg/L i 0.91 mg/L u sljedeća dva uzorkovanja kada je prisutno i veće ispiranje u skladu s klimatskim uvjetima i gnojidbom provedenom u rujnu, te zasićenjem i otpuštanjem s adsorpcijskog kompleksa tla, pri čemu zadnja dva uzorka prelaze granicu MDK.

Intensive agriculture is putting great pressure on the environment and therefore it is vital to rationalize its inputs, and to control and monitor the impact agricultural activities have on soil, water, and air, in order to achieve sustainability. For better understanding of the impact that conventional agricultural practices have not only on soil, but on water resources as well, two main objectives were established. The first one is to measure concentrations of nitrate (NO3-) and sulfate (SO42-) in lysimeter and drainpipe waters related to different nitrogen fertilization levels. The second one is to identify organic pollutants that potentially originate from used agrochemicals. The results of two-year investigating period (2014-2015) are presented in this study. The experimental field was established in Potok near Popovača on distric Stagnosols. The research contained ten treatments with four replications where different nitrogen fertilizer levels were applied: 1. Control (no fertilization), 2. N0 + P + K, 3. N100 + P + K, 4. N150 + P + K, 5. N200 + P + K, 6. N250 + P + K, 7. N250 + P + K + phosphogypsum, 8. N250 + P + K + zeolitic tuff + CaCO3, 9. N300 + P + K, and 10. Black fallow – tillage only. Phosphorous (P) and potassium (K) levels were constant, 120 and 180 kg/ha respectively. Each treatment area included two drainpipes (placed at the depth of 120 cm) and one lysimeter (at the depth of 80 cm) from which water samples were taken when discharge appeared. During the investigated period, 24 water samples for inorganic (13 from lysimeters and 11 from drainpipes) and 16 for organic substances analysis (six in 2014 and two in 2015 from lysimeters ; five in 2014 and three in 2015 from drainpipes) were taken. The concentrations of NO3- and SO42- were determined by suppressed ion chromatography (Dionex ICS-1000 system) using IonPac AS17-C separation column fitted with IonPac AG17 guard column. The gradient flow analysis was conducted using KOH as an eluent solution (10-30-10 mmol). Ultra-high performance liquid chromatography (UHPLC) coupled to time-of-flight mass spectrometry (Q- TOF/MS) was used for non-target screening and quantification of organic substances. This allowed the search of the entire spectrum of various organic compounds and their quantification at high resolution (> 10000 FWHM, full width half maximal), with accurate mass accuracy (< 1 ppm) and satisfactory sensitivity in fullacquisition mode. Research results indicated that NO3- content in both lysimeters and drainpipes increased with rising doses of N fertilizer. In the investigated period the daily concentration varied from 0.52–265 mg/L in both lysimeters and drainpipes, depending on the treatment, precipitation and agrotechnical measures. Higher average concentrations for each treatment were observed in water samples from drainpipes (up to 126 mg/L), which are placed deeper in the soil (120 cm) confirming that nitrates do not bond with soil particles and are leached into groundwater. Daily SO4 2- concentrations varied from 1-302 mg/L. As expected, the maximum average concentrations were recorded in treatment 7 with added phosphogypsum (184 mg/L in lysimeters and 105 mg/L in drainpipes), while the average concentrations on all other treatments were low (< 20 mg/L). Non-target screening revealed more than 400 different organic substances (agrochemicals, hormones, opioids, antibiotics and various other drugs) in water samples. The correlation with applied plant protection products was not observed. The focus of this study was three herbicides: atrazine, simazine, and isoproturon. Atrazine and simazine have been banned in Croatia since 2004, while isoproturon is still used. The average annual concentrations of atrazine, simazine and isoproturon in water from lysimeters in 2014 were 1.40, 0.20 and 0.21 μg/L, respectively. In drainpipes the concentrations were 0.44, 0.20 and 0.04 μg/L, respectively. The average annual concentration of atrazine, simazine and isoproturon in lysimeters in 2015 was 4.69, 8.70 and 0.78 μg/L, respectively. In drainpipes the concentrations were 0.82, 3.82 and 1.66 μg/L, respectively. Due to the fact that atrazine and simazine have not been used in Croatia since 2004 and there have been no records of isoproturon use in the investigated area since 1997, it can be assumed that these compounds persist in the environment for a considerable length of time.