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Conservation tillage is a type of land management that aims to minimize the frequency or intensity of tillage operations in an effort to protecting the soil by managing crop residue and limiting soil disturbance with minimum or no-tillage. Conservation tillage methods improve soil health and productivity, reduce runoff, increase soil carbon sequestration and limit the extent of erosion and also promote certain economic and environmental benefits as decrease in carbon dioxide and greenhouse gas emissions, less reliance on farm machinery and equipment, and an overall reduction in fuel and labor costs. Changes in the soil health status resulting in a diminished capacity of the ecosystem to provide goods and services for its beneficiaries, are define as soil degradation. The field experiment with different conservation tillage systems in maize production was conducted in 2021 in Čačinci and Križevci. Tillage treatments were: ST (plowing), CTD (conservation deep, loosening up to 30 cm with a minimum of 30% of crop residues) and CTS (conservation shallow, tillage up to 10 cm with a minimum 50% of crop residues). The following parameters were investigated: bulk density (ρv), packing density (PD), soil compaction (by penetrometer), soil organic matter (SOM), soil organic carbon (SOC), soil respiration, estimation of N-mineralization and C/N ratio. After the first year of research, a large heterogeneity of the researched parameters between the tillage treatments was recorded.

Climate Change (CC) today represent one of the most important and challenging existential threats at the local, regional and global level. These negative influences, which arise from drastically changing climate, are visible in all humans and natural aspects and sectors. One of the most important aspects, which is strongly connected with climate change and which is inevitably in a causally consequential relation relationship with it, is agriculture. To prevail these negative influences, many platforms strive to found some valuable and adequate sustainable approaches, measures and techniques. Many techniques (such as soil tillage, seeding/sowing, crop/plant protection, crop residue management) in crop and plant production, which is usually called "conventional", they are no longer adequate. They should be promoted/updated/renovated/ upgraded/adapted into sustainable techniques. According aforementioned "many platforms", Conservation Agriculture (CA) belongs to the one of these and represent very successful platform in adaptation and mitigation strategy to CC. CA is highly adaptive concept and with relative very easy applicative measures on different levels ; on local, regional and global scale. CA as measure of adaptation to CC is based on three basic principles: - Minimal soil mechanical disturbance, - Permanent soil surface cover (with crop residues and/or growing crops), - Crop rotation (species diversification). All three basic principles are interconnected by crop residues, as one of the most important factors of CA, on different ways and levels, as it: way and intensity of soil tillage, mass and type of crop residue, type of crops, biological yields, harvesting quality, activity of soil biology, soil chemical and physical quality, agroecological conditions, crop residue management, etc. Most often definition of CA is according amount of crop residues on soil surface. According this criterion CA is defined as a crop production system where at least 30% (up to 100%) of the soil surface is covered with crop residues after all tillage treatments and sowing/seeding are performed. In comparison to CA, and using same criterion, conventional soil tillage with plowing has up to 15% and reduced soil tillage up to 30% (usually from 15-30%) of crop residues on soil surface. Crop residues and their retention on the soil surface or near the soil surface have multiple and significant mostly positive, but in some cases conditionally negative impacts, especially in soil conservation tillage systems. Different effects of crop residues (positive or negative) on soil conditions and crop production (current and next growing crops) resulted from many factors, such as: amount, type and fragmentation of crop residues, different soil conditions in residues management, type of climate (dry or wet conditions), type of mechanization, intensity of crop rotation (short or intensified), etc. Generally, negative effect is mainly expressed through intensified development of disease and pests, slower soil surface warming and potential difficulties in soil preparation and sowing (large amount of residues). As the most important positive effects can be highlighted next: reduction of water and wind erosion, reduction of evaporation, better water infiltration, better water preserving, reduction of weed infection, intensification of soil biota etc. It is clearly visible from the definition that crop residues play a very important role in CA, and for this reason special attention is paid to this issue. Measuring/assessment of the amount of crop residue can be performed in several different ways, with prescribed appropriate methodology for each method. The basis of each measurement method is that it is carried out after the sowing of the next crop, and the measured values are expressed as a percentage of the soil surface coverage with crop residues. There are three basic methods for measuring of crop residues: a. line transects method (most popular and easy to use), b. Photo comparison method (more possibilities: photo camera, drone, remote measurement – satellite, radar polarimetry), c. Calculation method (complicated, demanding and time-consuming in creating but very easy to use). There are number of modifications and adaptations of these based methods and it is important to emphasize that each method has its advantages and disadvantages, and that accuracy of the results depends on a large number of parameters (e.g. precision/calibration of the method, data collecting method, agroecological and agrotechnical conditions). But whichever method of measuring/assessment is used, it is essential for conservation soil tillage to ensure the best possible coverage of the soil surface with the crop residue. Case study: The field experiment with different conservation tillage systems, different fertilization and soil conditioners, and different crops in rotation was conducted in 2021 in two different agroecological region in continental part of Croatian. Tillage treatments were: ST (standard tillage ; plowing up to 30 cm and different number of secondary tillage treatments), CTD (conservation deep tillage ; loosening up to 30 cm with a minimum of 30% of crop residues on the surface) and CTS (conservation shallow tillage ; tillage up to 10 cm with a minimum 50% of crop residues on the surface). Method for estimation of residue cover (in %) was line-transect method, and it was performed after all soil tillage operations and after sowing next crop. Already in early stage of research, after second experimental year (maize was grown in first and soybean in second year) percentage of crop residue was higher than is expected, but in expected distribution on both experimental sites. Higher soil covering was measured in western part of Croatia and lower in easter part. As it expected, highest soil covering was on CTS on fertilization according recommendation with application of liming and lowest on ST with decreased fertilization without liming. Generally, soil surface covering with crop residues according treatments were as follows: CTS>CTD>ST.

Conservation tillage systems, compared to conventional ones, have proven to be more effective from a biological, ecological and economic point of view, while at the same time preserving the ecosystem. Research with conservation tillage systems was conducted in 2022 on the experimental area of Križevci College of Agriculture (46° 01’ 38’’ N, 46° 33’ 32’’ E). The field experiment was set up according to a split plot experimental design with three main tillage treatments: ST (conventional, plowing), CTD (conservation, loosening with a minimum of 30% crop residues on the surface) and CTS (conservation, tillage up to 10 cm with a minimum of 50 % crop residues on the surface). Weed sampling was carried out during the critical period for weediness in soybean crops. The number and above-ground biomass of weeds was determined by counting individual weed species using a square of 0.25 m2 in four replicates per experimental plot. Weeds from each square were cut at ground level, counted, sorted according to species, dried at 65 °C and weighed. The applied herbicide treatments were uniform on all tillage treatments. Tillage had a statistically significant effect on the total number of weeds, the above-ground biomass and the number of weed species. The highest number of weeds was found in the CTD treatment (44.67 m-2), and the lowest in the ST treatment (7.33 m-2), with a statistically significant difference between ST and conservation treatment treatments. The CTS treatment resulted in the highest weed biomass (48.77 g m-2) but without a statistically significant difference compared to CTD (39.98 g m-2). The highest number of weed species was found in the CTS treatment (3.66 m-2), and the lowest in the ST (1.33 m-2), with statistically significant differences between all tillage treatments. All investigated weed parameters were, on average, the lowest in the conventional tillage system compared to the conservation systems. The CTD treatment resulted in a smaller number of weed species and a lower biomass compared to the CTS treatment, which indicates the need for further research into the impact of conservation tillage on the occurrence of weeds in soybeans.

Konzervacijski sustavi na različite načine utječu na ublažavanja klimatskih promjena uz pozitivan utjecaj na produktivnost biljne proizvodnje. Istraživanje s konzervacijskim sustavima obrade tla i kalcizacijom provedeno je 2021. godine u Čačincima (17.86336 E, 45.61316 N, n.v. 111 m). Poljski pokus postavljen je po split plot eksperimentalnom dizajnu u tri ponavljanja s glavnim tretmanom obrade tla: ST (konvencionalna s oranjem), CTD (konzervacijska duboka, obrada rahljenjem do 30 cm s minimalno 30 % žetvenih ostataka na površini) i CTS (konzervacijska plitka, obrada do 10 cm s minimalno 50 % žetvenih ostataka na površini) s podtretmanom kalcizacija. Uzorkovanje korova provedeno je dva puta (fenofaza V10 i R5). Ocjena pokrovnosti vršila se metodom vizualne procjene, a brojnost i nadzemna biomasa korova utvrđivala se brojanjem pojedinačnih vrsta. Dominantne korovne vrste bile su Ambrosia artemisiifolia L., Calystegia sephium (L.) R. Br. i Echinochloa crus-galli (L.) PB. Svi istraživani parametri zakorovljenosti u prosjeku su bili najmanji na kalciziranim tretmanima, a statistički značajan utjecaj utvrđen je za broj korova u V10 i pokrovnost u fenofazi R5 na kalcizaciji. Obrada tla značajno je utjecala na pokrovnost korova u R5, a najmanja je bila na CTD (24, 67 %). CTS tretman rezultirao je najvećim brojem korova (24 m-2), biomasom (134, 43 g m-2) i pokrovnosti (69, 84 %) ali bez statistički zanačajnih razlika u odnosu na ST i CTD te su se konzervacijski sustavi obrade u ovom istraživanju pokazali održivim u pogledu gospodarenja korovima.

European corn borer (ECB) is one of the most important maize pests. The aim of this study was to determine the effect of different soil and fertilization management on maize susceptibility to European corn borer attack. The experiment was set up in 2021 in Virovitica- Podravina County on maize hybrid OS378. Three treatments were included in the experiment. Treatment A – soil tillage: standard tillage (ST) and conservation system shallow (CTS), treatment B – liming: with liming (CY) and without liming (CN) and treatment C – fertilization: fertilization according recommendation (FR), FR+GeO2 (soil microbial biomass activator) (GFR), biochar (B) and biochar + FR (BFR). At the end of the vegetation ear weight (g), stem tunnel length (cm), ear shank damage (cm), number of larvae in maize stem and number of larvae in ear shank were recorded. Damage from ECB larvae for all tested parameters was greater on the CN compared to CY treatment and the ear weight was lower. CTS resulted in greater damage of maize stem and the number of larvae in the stem however, there was less damage to the ear shank and the number of larvae in the ear shank while the ear weight was also higher than the ST. BFR resulted in the highest ear weight on fertilization treatments and the lowest ear shank damage as well as the number of larvae in ear shank. Biochar treatment had the lowest ear weight, stem tunnel length and number of larvae in the maize stem, but also the greatest ear shank damage. According this results for all tested parameters from the ECB larvae, ear shank damage was the most important parameter in ear weight reduction.

As climate change (CC) is recognised as one of the main threats to food and feed security and safety, each concerned and interested party is working on finding the most elegant solution. The expected impact of CC on the presence of mycotoxins in food and feed is of great concern. One of the most adaptable and applicable platforms to combat climate change on a global level is conservation agriculture (CA). In 2021, an experiment at two different locations (eastern and western Croatia) was set up with different conservation tillage treatments (as part of the three main pillars of CA). One of the main goals of this project was to determine the influence of different conservation soil tillage treatments (in comparison with conventional) on the occurrence intensity of different types of mycotoxins (maize in 2021 year). Soil and maize were analysed and mycotoxin profiles were obtained. As expected, certain regulated mycotoxins were prevalent in maize, while emerging mycotoxins, Aspergillus and Alternaria metabolites had higher occurrence and concentrations in soil. The effect of tillage treatment showed differences in the concentrations of mycotoxins in both soil and maize, where conservation soil tillage treatment showed reduced mycotoxins concentrations. Only one sample exceeded the concentrations regulated for fumonisins, while other samples had all mycotoxin levels within legal limits.

Primjena konzervacijskih sustava tla učinkovit je način u sprečavanju degradacije tla i prilagodbe biljne proizvodnje klimatskim promjenama uz osiguravanje produktivnosti i stabilnosti prinosa. Cilj istraživanja provedenog 2021. godine na pseugleju u Čačincima (17.86336 E, Lat. 45.61316 N) bio je utvrditi utjecaj konzervacijske obrade, gnojidbe i kondicioniranja tla na prinos i komponente prinosa kukuruza s glavnim tretmanom obrada tla: ST (konvencionalna s oranjem), CTD- konzervacijska duboka (rahljenje s 30 % biljnih ostataka) i CTS-konzervacijska plitka (uz 50 % biljnih ostataka) s podtretmanom kalcizacije i pod-podtretmanom gnojidbe. Tretmani gnojidbe bili su: FR (prema preporuci, NPK 170:150:225), FD (50 % od preporuke), GFR (prema preporuci + GeO2 – biofi ziološki aktivator tla), GFD (50 % od preporuke + GeO2 ). Obrada tla i gnojidba u prosjeku su statistički značajno utjecale na prinos, hektolitarsku masu i masu 1000 zrna. Najveći prosječni prinos (8, 60 t ha-1), masa 1000 zrna (121, 80 g) i hektolitar (70, 15 kg hl-1) ostvareni su na ST tretmanu. Veći prinosi u prosjeku su zabilježeni su na svim kalciziranim tretmanima, a na tretmanu GFR ostvaren je najveći prinos kukuruza (9, 75 t ha-1). Na tretmanima CTD i CTS najveća masa 1000 zrna u prosjeku je ostvarena na tretmanu GFR, a najveća hektolitarska masa zabilježena je na ST tretmanu uz kalcizaciju i gnojidbu GFD. U ovom istraživanju kondicioniranje tla rezultiralo je povećanjem prinosa i komponenti prinosa kukuruza.

The concept of human-induced soil degradation is very old and dates back to the very beginnings of conscious human food production. From that time to nowadays our awareness and knowledge about soil degradation were significantly arise. As parallel ways, in recent times, different approaches and technique are developed to stop, prevent and/or restore degraded soils, with more or less success. Originality of the Conservation Soil Tillage (CST) is dating on the beginning of the last century, as the desperately attempt for soil preservation of its destruction. Nowadays, in period when climate change (CC) has become as one of the majors threatens in agricultural production (and not only), CST are set it up as one of the potentially best ways for combat to climate change. Leading by these three interlinking and strong-connected causality effect of cause-consequence-solution, research project "Assessment of conservation soil tillage as advanced methods for crop production and prevention of soil degradation - ACTIVEsoil" under Croatia Science Foundation were set up in 2020. The project was conceived and set it up on way to determine the level and time dynamics of changes in physical, chemical and biological parameters that indicate soil degradation by mutual comparison of the researched systems of crop production in different ways of soil management. Expected and planed outcomes, as most significant results from multi-year experimentation, are: - better insight into the degradation processes in the soil and the way they are mitigated, - the integration and consolidation of the postulates of CST itself with application in different agroecological conditions and for different crops, to reach and develop an optimal crop production system.

Soil quality needs to be based on its ability to provide certain functions. Soil quality can be divided into its essential ability as a substrate for crop growth and the dynamic part, which is influenced mainly by the users. Dynamic soil quality contains soil properties that can be changed in a short period of time and are affected by human activity. Soil quality can be divided mainly into physical, chemical and biological soil quality, although these components are in constant interaction with each other, which makes them difficult to separate. Until recently, the term “soil quality” was viewed in the context of plant production and crop productivity, as a result of physical, chemical and biological soil productivity. Soil productivity is the condition of the soil that indicates its ability to provide plants with accommodation under appropriate thermal conditions, favourable water-air relations and a sufficient supply of plants with essential nutrients. Soil productivity is affected by a number of factors such as climate, relief, soil type, soil organisms, weather and applied agricultural techniques. Intensive crop production can deplete the soil to the point that future production can be threatened. Healthy soils are key to developing sustainable crop production systems that they are resistant to the effects of climate change. Conservation agriculture is a concept in support of sustainable land management, environmental protection and climate change adaptation and mitigation. It is a farming system that promotes minimum soil disturbance (which reduces soil erosion and preserves soil organic matter), maintenance of a permanent soil cover (protective layer of vegetation on the soil surface suppresses weeds, protects the soil from the impact of extreme weather patterns, helps to preserve soil moisture, and prevent soils compaction), and diversification of plant species (crop rotation). Conservation agriculture enhances biodiversity and natural biological processes above and below the ground surface, which contribute to increased soil quality. Also, Conservation agriculture help to protect the environment and to reduce both the impacts of climate change on agricultural systems (adaptation) and the contribution of the agricultural practices to greenhouse gases. Increasing degradation of agricultural soils caused by a number of natural and anthropogenic factors puts the role of conservation agriculture, especially conservation soil tillage, as a measure that is able to cope with these problems, following the principles of sustainable soil management. Applying the conservation soil tillage principles, as a part of conservation agriculture, improves soil quality, optimizes crop yields and reduces investment costs in agricultural production. Adopting the conservation soil tillage principles agricultural activity can significantly reduce the negative impact on physical, chemical and biological complex of the soil, as well as other natural processes under climate change. Accordingly, the project “Assessment of conservation tillage as advanced methods for crop production and prevention of soil degradation” is underway, which aims to determine the possibility of implementing conservation tillage as a measure to improve soil quality, especially under climate change.

Good microbial activity plays a crucial role in soil health status and it is important for decomposition of organic matter, cycling of nutrients (especially P and N), formation of humus and stabilization of soil aggregates. It is known that Conservation tillage can positively affect higher accumulation of organic matter especially in the surface soil which can lead to a higher soil microbial activity. This activity can be measured through CO2 respiration from soil. Hence, the main objective of the study is how improved land management practices can affect evolved CO2-C which represents microbial activity as one of the most important soil health indicators. Two experiments were established in Croatia on two soil types Stagnosol and Gleysol both with acid soil reaction. Cultivated crop was corn and the treatments were: ST-Standard Tillage (deep mouldboard ploughing), CTD-Conservation System Deep (without ploughing and with minimum 30% of surface covered with plant residues), CTS- Conservation System Shallow (tillage up to 10 cm and minimum 50% of surface covered with plant residues). Liming CY- treatment with applied lime (according to recommendation) and CN-treatment without liming and fertilization, FR-according recommendation (NPK), FD-fertilization decreased by 50% compared to recommendation, GFR- fertilization according recommendation + 300 kg ha-1 Geo2 (biophysiological soil activator), GFD- fertilization decreased by 50% + 300 kg ha-1 Geo2. Soil samples were taken at two soil depths (0–15 cm and 15-30 cm). Measurement of evolved CO2-C is done by using commercial soil health test 24h Solvita CO2-burst test. CO2 respiration was significantly affected by tillage, fertilization and liming on both localities. Highest evolved CO2-C was measured on 15 to 30 cm on Gleysol (treatment CTS, CN, GFD) 193.00 CO2-C kg-1. On 0 to15 cm on both soil types the highest evolved CO2-C are recorded on CTS tillage treatments with liming and GFD fertilization (Stagnosol 95.37mg CO2-C kg-1 ; Gleysol 62.63 CO2-C kg-1). On both depths and localities, the lowest measured evolved CO2 was on ST. Concentrations of evolved CO2-C measured in CTS treatment confirms the positive influences of Conservation tillage on increasing microbial activity on acid soils especially in surface soil (0-15 cm) and also good applicability of Solvita CO2-burst test.

Soil organic matter (SOM) content is the key function for preventing soil degradation and rising of soil fertility. Basic benefits of SOM are physical (increases aggregate stability and soil water capacity and decrease soil crusting), chemical (increases cation exchange capacity of soil and availability of essential soil nutrients) and biological (represents habitat and food for numerous live organisms in soil). Furthermore, SOM plays a crucial role in soil carbon sequestration, as a consequence of soil containing the largest terrestrial carbon (C) pool mainly in the form of soil organic matter, which is very sensitive to climate changes, land use and agricultural management practices. The main problem occurs when we change management practice of native land (for example, turning forest and natural pastures in agricultural land) which, due to soil disturbance, causes rapid loss of organic matter. It is estimated that in the period of 50 years 30-50 % of the soil organic matter found under native forest can be lost after the forest was converted to agriculture. The main reason of that rapid loss is excessive tillage (conventional tillage - plowing) and also, inadequate crop rotation or absence of soil cover. Conventional tillage increases the oxygen content of the soil, stimulates soil microbes to decompose soil organic matter which leads to soil structure deterioration, disturbed soil-water relationships and finally the lower soil fertility. When organic material is not applied to the soil through organic fertilizers, crop residues or cover crops (siderate), soil organic-matter levels rapidly decline. In recent years, the promotion of less intensive tillage practices (conservation tillage or reduced tillage) as agricultural management has mange to mitigate some of mentioned negative impacts on SOM. The transition from conventional to conservation tillage can result in C stock increase especially in upper soil layers (0–30 cm) around 4.6 t/ha over ≥ 10 years. Higher SOM concentrations in the upper soil will not only increase soil fertility but also provide resilience to extreme weather conditions which are a consequence of climate change.

Istraživanja u Čačincima i Križevcima tijekom 2021. godine imala su za cilj utvrditi utjecaj tipa tla (na lokalitetu Čačinci - Stagnosol i na lokalitetu Križevci - Gleysol), sustava obrade (ST – standardna obrada, CTD – konzervacijska obrada duboka i CTS – konzervacijska obrada plitka) i dubine tla (0 – 20 i 20 – 40 cm), kao i njihovih interakcija na poljski vodni kapacitet (PVK) i gustoću pakiranja (Gp). Sadržaj gline u Stagnosolu kretao se od 31, 82 % (na dubini 0 – 20 cm) do 35, 23 % (na dubini 20 – 40 cm), a u Gleysolu od 8, 84 % (na dubini 0 – 20 cm) do 10, 37 % (na dubini 20 – 40 cm). Tekstura tla u Stagnosolu je praškasto glinasta ilovača (PrGI), a praškasta (Pr) u Gleysolu. Na vrijednosti PVK je značajno utjecao tip tla, obrada i dubina, te su utvrđene značajne interakcije tipa tla s obradom i tipa tla s dubinom. Najveći PVK izmjeren je na Gleysolu na CTS tretmanu (46, 14 %) i na dubini 20 – 40 cm (46, 25 %), dok je najmanji PVK izmjeren na Stagnosolu na CTD tretmanu (30, 34 %) i na dubini 20 - 40 cm (33, 28 %). Gustoća pakiranja je bila pod značajnim utjecajem tipa tla. Utvrđene su značajne interakcije između tipa tla s obradom i tipa tla s dubinom. Najmanja gustoća pakiranje izmjerena je na Gleysolu na CTD tretmanu (1, 42 g cm-3) i na dubini 20 -40 cm (1, 44 g cm-3). Najveća gustoća pakiranje izmjerena je na Stagnosolu na CTD tretmanu (2, 02 g cm-3) i na dubini od 20 - 40 cm (1, 93 g cm-3).

Increasing degradation of agricultural soils urges the need for following the principles of sustainable soil management. The importance of soil organisms for soil health and, consequently, sustainable agriculture in the future became widely acknowledged. FAO’s Status of the world’s soil resources in 2015 concluded that the loss of soil biodiversity is considered one of the main global threats to soils in many regions of the world. Conservation tillage has been associated with numerous soil quality parameters improvements including increased earthworm activity and biomass. Moreover, under conservation tillage earthworms can play a more important role by exploiting their abilities of bioturbation and impact on nutrient cycling. A long term experiment including three types of tillage (conventional tillage (ST), conservation tillage A (deep), conservation tillage B (shallow) and additional agrotechnical measures (liming, fertilizers, soil enhancer (Geo 2 ) and a crop rotation was carried out at the Čačinci location in Croatia. After four years the impact on earthworm communities and soil physico-chemical characteristics was assessed. The treatments with conventional/standard tillage system was the most detrimental for an earthworm community, both in terms of species number and biomass. Additionally, preliminary results on the first year of experiment on the second location will be presented, where the identical experimental will be carried out for four years.

Cilj rada bio je utvrditi alelopatski potencijal korovnih vrsta iz različitih sustava obrade tla. Alelopatski potencijal vodenih ekstrakata, pripremljenih od nadzemen mase običnog koštana (Echinocloa crus-galli (L.) P.Beauv.) i zelenog muhara (Setaria viridis (L.)P.Beauv.) prikupljenih na tretmanima s konvencionalnom (ST), dubokom konzervacijskom (CTD) i plitkom konzervacijskom (CTS) obradom tla, testiran je na klijavost i rast klijanaca salate. Alelopatski potencijal ovisi o korovnoj vrsti, sustavu obrade tla i mjerenom parametru. U prosjkeu su najveći inhibitorni potencijal na salatu imali vodeni ekstrakti pripremljeni od jedinki prikupljenih s tretmana duboke konzervacijske obrade tla.

Different conservation tillage systems play an important role in mitigating the negative impacts of climate change on crop productivity and preventing soil degradation. By changing a number of soil conditions, conservation tillage affects the change in weed levels. Weeds are the dominant biotic factor that most often negatively affects the performance of maize yields during the growing season, and especially in the critical period of weediness. Fertilization can increase the competitive ability of maize which causes a reduction of weeds occurrence and change in the composition of weed flora. Weed species amount, density and biomass play a significant role in maintaining the biodiversity of agroecosystems. The aim of this study was to investigate the impact of conservation tillage and fertilization on weed infestation in maize. Field experiment was performed in year 2021 at experimental site Čačinci (Stagnosol soil type) in Croatia (17.86336 E, 45.61316 N, 111 m a.s.l.) as a split plot experimental design in three replicates with soil tillage as the main factor and fertilization as subfactor. The soil treatments were as follows: CT (conventional, plowing), CTD (conservation, loosening with a minimum of 30% of crop residues on the surface) and CTS (conservation, shallow tillage with a minimum 50% of crop residues on the surface). Fertilization treatments were: FR – control treatment (according to the recommendation in amount of - NPK 170: 150: 225 kg/ha), FH (50% of the recommendation), GFR (according to the recommendation + GeO2 - biophysiological soil activator, 300 kg/ha), GFH (50% of recommendation + GeO2). Weed sampling and determination of weed species were performed twice during the maize growing season (growth stages V10 and R5). The applied chemical weed protection was uniform for all soil tillage and fertilizations treatments. Individual weed species were counted within the square of 0.25 m2 in four replicates per experimental plot to determine the weed density and cut off from the same square at ground level to determine aboveground biomass. At the same time, weed coverage was established on the same surfaces with visual assessment. The most numerous weed species were: Calystegia sephium (L.) R. Br., Ambrosia artemisiifolia L., Setaria viridis (L.) P. Beauv. and Convolvulus arvensis L. Tillage significantly affected the total number of weeds, weed aboveground biomass, number of weed species and weed cover in the first observation (V 10 – critical weed-free period for maize). All investigated indicators in average were the highest at the CTS treatment with statistical significance (p ≤ 0.05) in relation to conventional tillage (CT). The total weed number (12.33/m2) on CTS treatment was almost four times higher compared to CT (3.34/m2). Fertilization did not significantly affect the level of weediness, and the average values of all studied indicators were the lowest on the treatment GFH. The impact of tillage and fertilization on the total weed number in the second sampling (growth stage R5) was statistically significant (p ≤ 0.05). Significant interaction between tillage and fertilization was found, and the highest total number of weeds was recorded on control fertilization treatment FR for all tillage treatments. Treatment GFH in average resulted in more than 50% fewer weeds compared to FR (22.3/m2) with statistically significant difference. The highest total weed number was recorded on CTD tillage treatment (21.25/m2). The highest weed aboveground biomass (183.83 g/m2), number of weed species (2.75/m2) and weed cover (81.75%) in second weed observation were recorded on CTS tillage treatment with a significant statistical difference in relation to CT treatment. The results of this study indicate an increase in weediness of maize on conservation tillage systems and the positive effect of reduced fertilization with the addition of biophysiological soil activator to reduce weed levels in the later developmental stages of maize. The suitability of soil conservation systems and optimal fertilization in terms of weed management needs to be further investigated.

Conventional practices of intensive agricultural production led to soil degradation which is reflected through the degradation of physical, chemical and biological properties of the soil. Conservation agriculture by its principles (crop rotation, permanent soil cover and conservation tillage) prevents soil degradation and / or mitigates the consequences of soil degradation as a conditionally non-renewable natural resource. The one of the most important aspects of conservation agriculture is conservation tillage with purpose to care environment, soil health and productivity and plant growth. Conservation tillage, in addition to preventing soil degradation, results in multiple positive changes in soil such as: prevention of erosion, loss of soil organic matter, improve soil structure, reduction of CO2 emissions into the atmosphere, conservation of soil water, reduction of temperature aberrations, increase of soil biodiversity, etc. Conservation tillage has special important role in prevention or well as in mitigation of climate change and its environmental degradation process (such as desertification). One of the main benefits of conservation tillage is the reduction of runoff that carries with it the remnants of agrochemicals and soil sediments. Conservation tillage reduces the exposure of non- mineralized organic substances to microbial processes, thus reducing the decomposition of soil organic carbon and CO2 emissions. By establishing and implementing a strategy for sustainable land management, food production will be more successfully harmonized with the growing world population while preserving natural resources from the process of degradation.

Degradacija poljoprivrednih tala u sustavima intenzivne proizvodnje hrane postala je posljednjih desetljeća sve rašireniji problem. Na prostoru Republike Hrvatske naglasak se uglavnom stavlja na neke vidove kemijske degradacije, kao što su acidifi kacija, smanjenje organske tvari, onečišćenje teškim metalima i sl. Istovremeno, vrlo malo pažnje posvećuje se fizikalnoj degradaciji poljoprivrednih površina, koja se najčešće očituje kroz zbijanje i narušavanje strukture. Posljedica je to antropogenizacije, ali i utjecaja klimatskih faktora (količina, intenzitet i distribucija oborina, brzina vjetra, temperatura, insolacija). Na tlima narušene strukture stvara se pokorica, smanjuje vodopropusnost i aeracija, intenzivira površinsko otjecanje i erozija. Istraživanja pseudogleja na 25 lokacija u Slavoniji i Baranji ukazuju na slabo humozna tla (1, 35 – 2, 89 %) sa sadržajem gline 14, 23 - 42, 17 % te dominaciju praškasto glinaste teksture. Indeks stabilnosti strukture (S = 1, 41 – 3, 13 %), pokazuje visoki stupanj fizikalne degradacije na dubini do 30 cm. Nestabilnost strukture pojačava osjetljivost tala na pokoricu. Na ukupno 68% istraživanih pseudogleja utvrđen je visoki indeks pokorice (CI = 1, 74 – 2, 53 %) što upućuje na podložnost ovih tala intenzivnom stvaranju pokorice. Stabilnost strukture je u vrlo značajnoj pozitivnoj korelaciji sa sadržajem organske tvari (r = 0, 998**), a s glinom u značajno negativnoj korelaciji (r = -0, 398*).

Nitrogen is one of the most important elements of plant nutrition. Plants absorbit in mineral form and its deficiency is common in agricultural production. Once the fertilizer is applied in the soil, all forms of nitrogen can undergo a variety of chemical changes (denitrification, volatilization- on) and also leaching which has significant effect on nitrogen plant availability. Because of that, it is important to monitor nitrate rates and to isolate vulnerable areas of arable land which is the main aim of this study. Nitrogen needs for crops were calculated by using ALRxp computer model for fertilization recommendation. Visualization and prediction of calculated data was done by applying geostatistical empirical Bayesian kriging method. The mean value of nitrogen rate was 134.15 kg N ha-1. Geostatistical analysis reveals that the range between 120-160 kg N ha- 1 cover the most of Osijek-Baranja County and that, by visualization of nitrogen prediction rates, vulnerable areas of land can be detected. In these areas it is necessary to carry out a detailed soil analysis after which is only possible to make decisions about required actions.

Kukuruz kokičar od drugih tipova kukuruza razlikuje karakteristična promjena volumena zrna nakon izlaganja visokim energijama, što se još naziva i kokičanje. Karakteristike koje se mjere za ocjenu svakog hibrida kukuruza kokičara, osim visine uroda, jesu i volumen ekspanzije pri kokičanju, oblik kokice, te udio neiskokanih zrna, a što je podložno kako genetskim faktorima samog kultivara (veličina zrna, kemijski sastav zrna), tako i udjelu vlage zrna, oštećenjima zrna, no, također i metodi samog izlaganja zrna visokim temperaturama, kao i trajanju samog procesa kokičanja. Standardizirana metoda mjerenja ekspanzije osniva se na kokičanju u posudi putem zagrijavanja ulja, no, zamjera joj se sporost i nepraktičnost. Alternativni način kokičanja jest putem aparata na vrućizrak, brza metoda kojom je moguće ispitati karakteristike kokičanja zrna kokičara za sve vrijeme dorade i skladištenja zrna kukuruza kokičara, te, sve rasprostranjenija u masovnoj konzumaciji kukuruza kokičara, upotreba mikrovalnih pećnica, koja preuzima primat u načinu konzumiranja kukuruza kokičara, kako zbog brzine pripreme, tako i zbog dužine zadržavanja željenih svojstava proizvoda nakon pakiranja, te mogućnosti dodavanja različitih okusa.U ovom istraživanju usporedno su provedena kokičanja šest komercijalnih hibrida kukuruza kokičara (Bulut OS, B12139, B1214, N1H262, B14262 i B0860) putem tri metode: K1) kokičanje u posudi s uljem, K2) aparat na vrućizrak, te K3) mikrovalna pećnica, u četiri ponavljanja. Za sve tri metode kokičanja korištena je ista težina zrna (77 g) s istom vlagom zrna (13.5%), a za metode kokičanja u posudi i u mikrovalnoj pećnici dodatno je upotrijebljena ista količina ulja (21 g) i kuhinjske soli (2 g), zasnovano na normativima za pripremu pakovina za mikrovalnu pećnicu. Vrijeme kokičanja za metodu zagijavanja u ulju i na vrući zrak ovisilo je o procjeni kraja kokičanja za svaki uzorak posebno, dok je za kokičanje u mikrovalnoj pećnici korištena ista postavka same pećnice za pripremu kokica za sve uzorke. Volumen ekspanzije mjeren je putem mjerne posude, dok je broj neiskokičanihzrna mjeren prebrojavanjem istih.Rezultati su pokazali da postoje razlike volumena kokičanja i broja neiskokičanih zrna među kultivarima, gdje je najveći volumen kokičanja postigao N1H262 a najmanji B0860, koji je ujedno imao i najviše neiskokičanih zrna. Razlike između metoda kokičanja nisu bile signifikantne, što navodi na zaključak da su metode ispitivanja volumena ekspanzije kukuruza kokičara komplementarne za istu masu zrna.

On global as well as regional scale, desertification or some of its effects (usually much more visible on local scale) are spreading rapidly in the last decades. Since the desertification on global level is recognized as one of the most important threats to land/soil/agriculture, our perceptions regarding desertification, are very changed. Essentially, desertification as a threat is known from ancient times, sometimes with cataclysmic results (e.g. collapse of civilizations), but its mechanisms are still not very well known. In present time and possible in near future the main multiplier of negative desertification effects is climate change. At the same time, direct result of climate change (not always but usually, and in future probably most frequently) is drought which is recognized as one of the most degradable extreme events in nature. These three factors are in very closely, interconnected, and they can be trigger and/or consequence of each other. Many negative effects result from that relations and includes every human and natural aspect as well as economy sectors. Some of these negative effects, which affect soil and agriculture on the most important ways, are: soil erosion, loss of (agro)biodiversity, decreasing crop production (mainly yields and crop types), decreasing livestock production (mainly as consequence of insufficient feed production), reduce water quality, loss of soil fertility, soil salinization, loss of soil organic matter, etc. All these phenomena lead to the degradation of the physical–chemical–biological complex of soil. Expected negative consequence of desertification, as results of its negative natural implications, as major can be listed as: reduction in food production and in the same time increasing food insecurity, loss of livelihoods, poverty and migrations. Possible solutions related to desertification and drought can be divided to proactive and reactive approaches with different measures for prevention and restoration. According to the aforementioned, major desertification patterns follow the next algorithm or scheme: causes – consequences – solutions – actions. Currently the only thing that we can and must do is act.

Istraživanja reakcije ozime pšenice i kukuruza na reduciranu obradu, pri različitim dozama gnojidbe dušikom, provedeni su tijekom 2013. (kukuruz) i 2013./2014. (oz. pšenica). Istraživanja su provedena na lokalitetu Čačinci, na tipu tla pseudoglej, na pet tretmana obrade tla: konvencionalna – OR, podrivanje – PO, rahljenje – RA, tanjuranje – TA, direktna sjetva – DS i tri razine gnojidbe dušikom: N1 – gnojidba umanjena za 50 % u odnosu na gnojidbenu preporuku, N2 – gnojidba prema gnojidbenoj preporuci i N3 – gnojidba uvećana za 50 % u odnosu na gnojidbenu preporuku. Najveći utjecaj na sve istraživane komponente imale su vremenske prilike, a zatim varijante obrade tla. Najveći prinosi zrna ozime pšenice ostvareni su na varijantama PO (5, 14 t ha-1) i RA (5, 06 t ha-1). Najveći prinos zrna kukuruza ostvaren je na varijanti OR (10, 23 t ha-1), dok je razlika u visini prinosa između ostalih istraživanih varijanata obrade tla bila vrlo mala. Varijante obrade tla TA i DS, u ovim su se istraživanjima pokazali inferiornima u usporedbi sa sustavima kod kojih se tlo obrađuje/rahli na veću dubinu. Između varijanata gnojidbe N2 i N3, nisu utvrđene opravdane razlike u visini ostvarenog prinosa zrna, s tim da je kod nekih pokazatelja, kod obje istraživane kulture, najveća vrijednost poljoprivrednog prinosa utvrđena kod varijante N2.

The aim of this research, performed in eastern Croatia during 2010/2011, was to evaluate the most suitable plant species for soil protection and covering in the fallow period. The field experiment organized as a completely randomized block design in four repetitions included 11 cover crops treatments: R (rye), W (winter wheat), F (lacy phacelia), P (field pea), V (hairy wetch) as single crops and cover crops mixtures RP, RV, WP, WV, FP and FV. The determination of plant density and aboveground biomass production (dry matter, DM) was used to estimate the most suitable plant species for efficient soil covering. The highest plant density was recorded on W treatment (484 m-2) with confirmed statistically significant differences compared to other treatments. R treatment stood out as the most suitable for soil covering with the highest recorded DM (317.88 g m-2), followed by RV (278.82 g m-2). Comparing the mixtures of cover crop, the best treatments proved to be WV with the highest plant density (328 m-2) and RV with the highest DM (278.82 g m-2) production.

Tijekom trogodišnjeg istraživanja (2008./09.-2011.) provedenog na lesiviranom tlu Istočne Hrvatske u blizini Valpova, istraživan je utjecaj ozimih pokrovnih usjeva na zakorovljenost u razdoblju između žetve soje do sjetve kukuruza kokičara (Zea mays everta Sturt.), zakorovljenost u usjevu kokičara, te rast, razvoj, prinos i komponente prinosa kukuruza kokičara. Pokus je proveden po načelu ekološkog uzgoja, a postavljen je kao potpuno randomizirani blok dizajn u četiri repeticije s 12 tretmana ozimih pokrovnih usjeva: N-kontrola bez pokrovnog usjeva, pojedinačni pokrovni usjevi: R-ozima raž, P-ozima pšenica, F-facelija, Sg-stočni grašak, Vic-ozima grahorica; te smjese ozimih pokrovnih usjeva RSg, RVic, PSg, PVic, FSg i FVic. Dominantne korovne vrste u provedenom istraživanju bile su: Matricaria chamomilla L. i Arabidopsis thaliana L. u ozimim pokrovnim usjevima, te Ambrosia artemisiifolia L., Chenopodium album L., Amaranthus retroflexus L., Echinochloa crus–galli (L.) PB. i Setaria glauca (L.) PB. u kukuruzu kokičaru. Najmanju zakorovljenost imale su smjese PSg, RVic i PVic, te pojedinačni pokrovni usjevi R, Vic i P sa statistički značajno manjim brojem korova u odnosu na kontrolu. Najprinosniji tretmani po ostvarenoj nadzemnoj masi bili su RVic, RSg, R i P. Vremenske prilike značajno su utjecale na zakorovljenost, a najveći broj korova utvrđen je u izrazito vlažnom razdoblju 2010. godine. Zakorovljenost u kukuruzu kokičaru u odnosu na kontrolu u prosjeku je bila značajno veća na tretmanu P, kod sklopa kukuruza kokičara nije bilo razlike, dok je visina kukuruza kokičara bila niža na tretmanima R i FVic. Najveći prinos kukuruza kokičara ostvaren je na smjesi PVic (2,5 t ha-1) u 2010. godini, dok je u prosjeku, u odnosu na kontrolu, prinos bio viši na tretmanima PVic i FVic. Tretman Sg rezultirao je najvećom prosječnom hektolitarskom masom i masom 1000 zrna kukuruza kokičara u odnosu na kontrolu. Smjese žitarica i leguminoza pokazale su se učinkovitije u suzbijanju korova u odnosu na pojedinačne pokrovne usjeve, a tretmani PSg, RVic i RSg mogu se preporučiti kao najučinkovitiji u suzbijanju zakorovljenosti., Three year research (2008/09-2011) at the lessive soil of the Eastern Croatia near town Valpovo has been conducted in order to establish the impact of winter cover crop treatments at weed population between soybean harvest and seeding of the popcorn maize (Zea mays everta Sturt.) crop, weed in popcorn maize crop, as well as growth, development, yield and yield components of the popcorn maize as the main crop. The research has been conducted in accordance with organic rules, and it has been set up as complete randomized block design in four repetitions with 12 cover crop treatments: N-control, no cover crop, single cover crops: R-winter rye, P-winter wheat, F-phacelia, Sg-fodder pea, Vic-hairy vetch; and cover crop mixtures: RSg, RVic, PSg, PVic, FSg and FVic. Dominant weed species determined in this trial were: Matricaria chamomilla L. and Arabidopsis thaliana L. found in winter cover crops, and Ambrosia artemisiifolia L., Chenopodium album L., Amaranthus retroflexus L., Echinochloa crus–galli (L.) PB. and Setaria glauca (L.) PB. in popcorn maize. The least weeded were cover crop mixtures PSg, RVic and PVic and single cover crops R, Vic and P, with significantly lower number of weed in comparison with the control. Treatments with the highest shoot production were RVic, RSg, R and P. Weather did influence significantly weedeness, especially in very moist period of the year 2010. The weedness in popcorn maize, in comparison with control, was higher at treatment P, main crop density was not affected by cover crop treatments, whereas height of the popcorn maize was lower at treatments R and FVic. The highest popcorn maize grain yield was recorded at PVic treatment in 2010 (2.5 t ha-1), whereas, in average, higher yields, in comparison with control, were recorded at PVic and FVic treatments. Treatment Sg had the highest average hectolitre weight and 1000 grains weight in comparison with control. The mixtures of cereals and legumes were proven to be more effective in weed suppresion in comparison with single cover crop treatments, whereas treatments PSg, RVic and RSg can be recommended as the most effective in weedness control.

During the seven-year period of research, 13, 085 samples of soil have been collected in East Croatia. Using the gained soil information, eight indicators which influence relative soils suitability assessment for crops have been singled out. While taking into account the natural laws of selected indicators and, an expert model which describes every indicator via functions has been created. The model was conceived as a tool that could be changed very easily, that is, adapted to various crops and agroecological conditions. Minimal estimated relative soil suitability assessment by Relative Soil Suitability Assessment (R.S.S.A.) model was 34.4%, and maximal was 95.2%. The largest sample number, 7, 768 of them, was located in the moderately suitable class. On the example of Osijek- Baranja County, the model has proved itself to be precise in comparison to the real situation in the field. Also, by implementing the geostatistical method of kriging, a prediction of the production area has been done, and with the maps that have been created through this method, we can easily use to detect problematic agricultural areas.

Different soil tillage practices affect soil on many different ways but predominantly on its physical, chemical and biological aspects. Some of the tillage's most influential impacts are: water content and availability, temperature, aeration, structure, density, compaction, nutrient cycling, organic matter transformation and dynamics, organism population and diversity. Intensity of tillage disturbance of the soil determines many causality relations of all soil compounds and influence levels of soil degradation and adaptability for present and future crop production. In different agroecological regions as in very similar agroecological conditions, exist different and sometime very opposite approaches to philosophy of soil tillage in crop production which consequently result, from year-to-year, in significant variation of average crop yields. In spite of many efforts to be replaced with some less degradable soil tillage systems or technique, mouldboard ploughing still remains as main tillage system in Europe. In same time, in some other world regions situation is much better and ploughing appear only sporadically and rarely (eg. Canada, USA, South America, Australia). Reasons for this variability and sometimes very diversified approach in not simple and one-way explaining. Main reasons could be divided in two main groups: Economic and social development (eg. knowledge, tradition, technics, technology, science) and Agroecological conditions (eg. climate, soil, water, crop, landscape). In last few decades as a factor which needs to be unavoidable included in every serious calculation and / or plan for successful crop production is climate change. Changes of boundaries of some climatic indicators due to climate change (mainly precipitation and temperature), and through its expression, as drought for instance, could drastically affect agricultural production. Regarding this and above-mentioned specifics, today there are different concepts of crop production that exist on global scale. The main concepts that are needed to mention are Conservation agriculture, Sustainable land management and in recent times Climate smart agriculture. Every one of them are cross- connected and includes soil tillage as one of its most important pillars. Today, every advanced approach to crop production necessarily needs to include site- specific principles (based on agroecological conditions) in application of any measures in crop production, including soil tillage. These approaches need to be in way of reduced or conservation soil tillage systems. Main modern principles of soil tillage imply as main excluding mouldboard ploughing as necessary, less soil tillage trafficking, better organic matter (residue) management, prevention to soil degradation (primarily soil erosion), shallow residue incorporation or their leaving on surface.

Agriculture production (crop and/or livestock) as a representative of primary production sector, is extremely vulnerable to the influence of climate change (CC) and its effect. Nowadays, crop/livestock/food production must meet the growing needs of population with minimization of negative influence on all ecosystems and entire environment. In last decades referent international institutions reported its recent results about CC trends. These results indicate trends in increasing of many negative climate effects in South and South-Eastern Europe, especially related to desertification which shows significant and constant progress northwards. Soil/land degradation through decreasing levels of organic matter and in the same time organic carbon in soil (which both regulates many vital functions in soil/land), are strongly correlated with desertification. Drought (as one of the most degradable extreme event) has primary influence on decreasing on quality and quantity of crop production, which consequently effects on livestock production. Desertification can be triggered and/or a consequence of drought and changes in precipitation patterns (as well as inadequate crop production and soil tillage, overgrazing, etc.), and represent pathway for further multilevel soil/land degradation (eg. erosion, physical, chemical and biological degradation), decreasing crop/livestock production, reduction of (agro)biodiversity, loss of soil organic matter and organic carbon, etc. Desertification, drought and agriculture are in strong correlation/linkage and one could trigger other. Changes of boundaries of some climatic indicators (such as precipitation and temperature), and through its expression, as drought for instance, could drastically affect agricultural production. Since the effects or consequences of CC becomes more serious, great efforts are targeted in way to find or create useful technology which has main intention, prevail or adapt or mitigate these negative effects. Common for all of different approaches are the same prefix ""conservation"" and different suffix's, namely: agriculture, crop production, soil tillage, livestock production, pest control, food security, etc. To prevail many of these negative influences on agricultural production and in the light of growing population, application and intensification some of sustainable approaches (eg. conservation agriculture) will not be optional but necessary.

The underlying idea of mitigating climate change with biochar is based on a negative process, because in the process of pyrolysis of organic matter, more CO2 is sequestered (negative emission) compering to burning in oxygen rich environment (zero emission). There are currently many different processes of energy production from renewable sources (biomass) in the world. But, three most mentioned mitigation scenarios that include carbon dioxide removal are conventional biomass energy production system, carbon capture and storage and biochar production system. The first conventional biomass energy production system is based on the fact that plant with growth captures CO2 by the natural process of photosynthesis and that the incineration or decomposition of biomass remains emission to zero. Currently there is a lot of thinking about abandoning such technology. Because with that kind of approach we could question ourselves, what to produce food or energy. Also, removal of the complete organic matter from soil surface has devastating impact on soil fertility and health. Another way is to produce energy from biomass with carbon capture and storage. The process is based on the use of biomass for energy production and the capture and storage of CO2 in tanks (for example below Earth's surface). Such system has a negative CO2 emission, but there is a still problem with biomass sources (forests, crop residues). It is also questionable its cost-effectiveness (expensive process) and functionality (possibility of re-leaking CO2 from underground cavities or tanks). The third system is the production of a biochar as an excellent soil amendment or a combined system of production biochar and energy. Such system would produce the least energy by comparing to the above- mentioned two systems, but the only one that could, with the energy production, positively influence on soil fertility and sequestration of CO2.

Use of cover crops is usually considered as useful practice which contributes to agroecosystem sustainability with a special emphasis on plant production. The positive impact of cover crops implementation in plant production systems on numerous chemical, physical and biological properties of soil as well as water quality improving is well known. The role of cover crops in the maintenance and increase of biodiversity is also a very important function why cover crops should be always present part of crop rotation. Due to today's awareness of climate change and well- known facts about the positive effects of using cover crops there is a need to understand whether and how the cover crops can help in climate change mitigation. Soil covering is the first and primary role of cover crops. Covered soil has potential to reflect more light compared to bare soil because of albedo changing caused by the presence of plant cover. The presence of cover crops thus leads to greater light reflection instead of absorbing the significant amount of light and heat. Soil carbon sequestration is one more function of cover cropping in climate change mitigation. With cover crops incorporation (input of organic residues) as one of the termination possibilities sequestrated atmospheric carbon returns back to the soil. Cover crops sown in fallow period greatly affect the nitrogen loss from soil. They can reduce it by preventing soil erosion and runoff. Nitrogen leaching is reduced because of cover crop uptake of residual nitrogen from previous crop. Otherwise there is a risk of nitrogen loss by wash away into surface and groundwater or volatization from the soil. Catch crop function in this case reduce possibility of formation of nitrous oxide (N2O) which has far bigger warming potential compared to CO2. Legume cover crops can leave significant amounts of nitrogen in the soil available for cash crop and thus reduce the need for N fertilizer use whose production and transport takes a part in greenhouse emissions. With cover crops incorporation other plant nutrients also becomes available for cash crops after cover crops decomposition and mineralization which reduces the need for mineral fertilizer application especially if the cover crops are in a continuously longtime use. Introduction of cover crops in plant production systems can contribute to mitigate the climate changes effects by increasing albedo and carbon sequestration, decreasing nitrogen loss and mineral fertilizer consumption and should be included in agricultural practices which are recommended for climate change mitigation.

Climate change has already significantly impacted agriculture and is expected to further impact directly and indirectly food production. According to FAO, the world's population will increase by one third over the next 30 years and agricultural production will have to increase by 60 % to satisfy the expected demands for food if current consumption growth trend continues. All aspects of agriculture production must transform itself if it is to feed a growing global population and provide the basis for economic growth and poverty reduction. To achieve food security and agricultural development goals, adaptation to climate change will be necessary. Right now, agriculture is faced with tree different close connected challenges: ensuring food security by increasing productivity, mitigation and adaptation agriculture production to climate change. Resolving these challenges will increase global pressure on natural resources, soil and water respectively. This approach implies radical changes in our eating systems. In order to achieve the goals, food systems must at the same time become more efficient and more robust at all levels - from farm to global level. Using resources must become more efficient (use less land, water and others inputs to produce more food more sustainable) and become more resistant to changes and stress. The concept of climate-smart agriculture (CSA) covers the way forward for food safety in a changing climate. Climate smart agriculture is not a new agricultural system, neither a set of practices. CSA is a new approach to help guide actions to transform and reorient agricultural systems to effectively and sustainably support development and food security under a changing climate. CSA is composed of three main objectives: 1. sustainably increasing food security by increasing agricultural productivity and incomes ; 2. adapting and building resilience to climate change ; 3. developing opportunities for reducing greenhouse gas emissions compared to expected trends. The aims of this concept are to improve food security, help communities adapt to climate change and contribute to climate change mitigation by adopting appropriate practices, developing enabling policies and institutions and mobilizing needed finances.

Popcorn maize differs from other maize types by a possibility of grain volume change after high energy exposure, which is also referred to as popping. The characteristics that are measured for the evaluation of each maize hybrids, beside of the grain yield, are also the volume of popping expansion, the form of popped popcorn, and the incidence of unpopped grains, all of which are susceptible to genetic factors of the cultivar itself (grain size, chemical composition of grains), the content of grain moisture, and grain damages, but also the methods of grain exposure to high temperatures, as well as the duration of the exposure process itself. The standardized method of measuring the expansion is based on a heating oil in the pot, but it is slow and impractical. An alternative method of heating is by means of a hot air appliance, a quick method of examining the characteristics of popcorn popping during all phases of grain cleaning and storing of popcorn, and more popular in wide consumption of popcorn, the use of microwave ovens, which takes on primacy in the way of popcorn consumption due to the speed of preparation, as well as the length of keeping the desired properties of the product after packaging, together with the ability of adding different flavors. In this study, six commercial popcorn hybrids (Bulut OS, B12139, B1214, N1H262, B14262 and B0860) were scattered through three methods: heating by oil in pot, a hot air machine and a microwave oven, all done in four repetitions. For all three methods of popping, the same weight of grain (77 g) was used with the same grain moisture (13.5 %), while the same amount of oil (21 g) and kitchen salt (2 g) was used additionally for heating methods by oil in the vessel and microwave oven, in accordance with the normatives for the preparation of the microwave oven packages. The heating time for the heating method in oil and hot air depended on the appraisal of the end of the popping for each sample separately, while for cooking in the microwave oven the same popcorn setting of the cooking oven for all samples was used. The volume of expansion was measured by measuring vessel, while the number of unpopped grains was measured by counting the same. The results showed that there were differences in the volume of popping and the number of unpopped grains among cultivars, where the largest volume of popping was achieved by N1H262 and the smallest by B0860, which also had the most unpopped grains. The differences between the popping methods were not significant, which suggests that methods of testing the volume of the popcorn expansion are complementary for the same grain mass.

Kukuruz kokičar (lat. Zea mays L. everta Sturt.) posebna je podvrsta kukuruza tvrdunca, čije zrno usled zagrevanja puca ("koka"), formirajući tzv. "kokicu". Moderna arheološka istraživanja zaključuju da je kokičar najverovatnije prvi kukuruz upotrebljen u ljudskoj prehrani. Sama tehnologija uzgoja ima specifičnosti u odnosu na merkantilni kukuruz. Zbog sitnijeg, okruglijeg zrna, treba prilagoditi sejalicu i dubinu setve za što preciznijom setvom zbog ujednačenijeg nicanja i ravnomernije gustine. Setva se može obavljati i no-till sejalicama, što je preovladavajući način setve kokičara u SAD i u Argentini, čime ulaganja u agrotehniku drže na nivou od najviše 1/3 ulaganja koje ima evropski proizvođač. Noviji hibridi kreirani su za gušće setve, te tu u obzir dolazi i setva tzv. "twin row" sejalicama, koje seju dva "cik-cak" reda, time omogućujući veći vegetacioni prostor po jednoj biljci, pa se broj biljaka može povećati i do 120 hiljada po ha. Budući da je koren slabiji, a stabljika često tanja od merkantilnog kukuruza, moderna primena đubriva tokom vegetacije prednost daje folijarnoj primeni, gde se hraniva dodaju direktno preko lisne mase, a preferiraju se folijarna đubriva koja sadrže više hraniva, ne samo azot. Najkritičniji deo proizvodnje je sama berba, gde berba u zrno mora početi tek kad je vlaga zrna ispod 16-17%, jer se pri većoj vlazi mašinskom berbom može oštetiti epikarp, što utiče na slabije kokanje. Zapremina kokanja zavisi od vlage, te je najveća pri 13-14% vlage, zato je izuzetno važno postići i održavati tu vlagu. Novi, tzv. "samosušeći" silosi, s autonomnom kontrolom sušenja, preporuka su za sušenje i kondicioniranje vlage kod kukuruza kokičara.

Conservation soil tillage is known as one of the most adaptive techniques which arise as more effective way to combat primarily negative influence of climatic changes especially in last two decades. Heterogeneous agroecological conditions and unsuitable soil tillage techniques on wide scale influence yield levels from year-to- year. Yields variation primarily depends on climate aberrations but also on variation of extreme meteorological conditions. Most common, and at the same time most dangerous weather conditions are represented with severe water and temperature regime. Both, water and temperature regime, have influence not only on yields but on other aspects which are in physical, chemical and biological domain. Since agriculture is faced with changing climatic conditions and with consequences which already arise, soil tillage plays a major role in soil vulnerability to climatic change and affects many soil quality aspects. According to 15 years of experimental results it can be concluded that conservation soil tillage, as a component of conservation agriculture, represents one of the main technology operations in crop production whose proper application could significantly improve yields. Main studied crops (Maize, Wheat and Soybean), depending on the soil tillage system, has shown different levels of reaction to extreme or severe weather conditions. Besides higher yields, arising side effects are mainly positive (reduction of soil erosion, increase biogenity and quality of soil, less traffic and soil compaction alleviation, nutritional status and quality traits of crops, weed infestation etc.), but are still in the background of wide rang conservation soil tillage adoption. Experiments with main goal of choosing the "best cropping system" or "best solutions" are a process which needs to be elaborated according to site- specific methods and crop- specific responses to mitigate climate threats. In this process, application of conservation soil tillage principles has a unique and specific role which can make a difference from successful and sustainable crop production compared to traditional principles. Since climatic changes do not follow national borders and since agriculture is extremely vulnerable to them, a common action to find adequate and effective measures to face climatic changes is an imperative. Conservation soil tillage is one of the best possible ways to combat primarily negative influence of climatic changes and consequently severe weather conditions.

Laboratorijske metode za mjerenje respiracije tla kao što je titracijska metoda često su složene i vremenski zahtjevne. Kompanija Solvita® razvila je 24-satnu novu brzu metodu koja se bazira na primjeni pH-osjetljivog gela. On detektira respiraciju CO2 unutar standardizirane inkubacijske posude u kojoj se nalazi uzorak tla koji se vlaži te tako imitira prirodni ciklus sušenja i vlaženja tla. Nakon 24 h, gel se uklanja iz posude za inkubaciju i analizira na digitalnom elektroničkom čitaču boja te se izražava kao mg CO2-C kg-1 tla. Cilj rada je testirati primjenjivost nove brze metode i utjecaj biougljena na respiraciju tla. Istraživanja respiracije tla provedena su tijekom vegetacijskog razdoblja 2016. godine na kiselim tlima na dvije lokacije u Osječko- baranjskoj i Virovitičko- podravskoj županiji. Uzorkovanje tla provedeno je tri puta tijekom vegetacije kukuruza. Biougljen je bio glavni faktor s tretmanima: kontrola, 5, 10 i 15 t ha- 1 biougljena. Prosječna vrijednost respiracija tla izmjerena na lokaciji u Virovitičko- podravskoj županiji bila je statistički značajno viša od vrijednosti mjerenja provedenog na lokaciji u Osječko-baranjskoj županiji. Također, primjena biougljena u najvišoj dozi, u odnosu na ostale tretmane, nije statistički značajno djelovala na povećanje respiracije CO2. Iz provedenih istraživanja može se zaključiti da je biougljen ostao stabilan u tlu, odnosno postignuta je sekvestracija ugljika te da je primijenjena brza metoda mjerenja respiracije CO2 uvelike ujednačila i pojednostavila laboratorijska mjerenja.

Prikazani su rezultati istraživanja provedenog 2009. godine. Istraživan je utjecaj različitih varijanata obrade tla na otpor tla u soji. Varijante obrade tla bile su OR - konvencionalna obrada tla ; TR - tanjuranje ; RT - rahljenje i tanjuranje ; NT - izostavljena obrada tla. Tip tla na kojem je provedeno istraživanje je močvarno hidromeliorirano tlo. Pokus je postavljen po split-plot metodi. Prosječni otpori tla, mjereni u cvatnji soje, nisu značajnije utjecali na ukorijenjivanje soje ; OR (1, 57 MPa)

Optimizacija gnojidbe predstavlja jedan od temeljnih uvjeta održivosti biljne proizvodnje. Određivanje količine gnojiva, vremena i dinamike njegove primjene u ratarskoj biljnoj proizvodnji još uvijek se nerijetko obavlja empirijski. Ovakav pristup ima višestruko negativne implikacije na okoliš, odnosno tlo, vodu i zrak. Najprimjenjivanije, a ujedno i gnojivo s najjačim onečišćujućim efektom po okoliš, je dušično gnojivo, snažnog je "prinosotvornog učinka" i nezamjenjivo u ostvarivanju visokih prinosa. U primjeni mineralnih komponenti gnojiva pa tako i dušika treba biti iznimno pažljiv, budući da je njegova dinamika i kruženje u prirodi vrlo složena. Primjena dušika u prekomjernim količinama uzrokuje njegov gubitak, posebice u uvjetima prekomjerne vlažnosti i descedentnog kretanja vode što rezultira njegovim premještanjem u vodotokove. Istraživanja koja su za cilj imala utvrditi optimalnu razinu primijenjenog dušika, a u skladu s dušičnom direktivom, provedena su za tri najzastupljenija usjeva istočne Slavonije kukuruz, ozimu pšenicu i soju. Gnojidbeni kalibracijski pokusi postavljeni su na dva lokaliteta: Ćelije u Vukovarsko-srijemskoj županiji i Šljivoševci u Osječko-baranjskoj županiji. Istraživani su slijedeći pokazatelji: razina podzemne vode, koncentracija N-NO3- i N- NH4+ u podzemnoj vodi i tlu, koncentracija N, P i K u nadzemnoj biljnoj masi po fenofazama porasta, u žetvenim ostatcima i u zrnu, potencijal mineralizacije i visina uroda. Bilanca dušika u tlu je često negativna, no pravilnim gospodarenjem gubici se mogu svesti na najmanju mjeru. Ovakav pristup omogućava praćenje dinamike raspoloživosti hraniva u tlu i usvajanja od strane biljaka te primjenu dušika u skladu s biološkim, ekonomskim i ekološkim uvjetima.

Rad obuhvaća rezultate istraživanja tijekom 2007. godine na lokalitetu Darda gdje je istraživan utjecaj različitih načina obrade tla na broj biljaka soje, masu 1000 zrna i hektolitarsku masu zrna te urod zrna soje. Istraživanje je obuhvatilo 4 varijante obrade tla: OR - oranje 30 cm ; TR - tanjuranje 12 cm ; RT - rahljenje i tanjuranje 35 cm i NT - izostavljena obrada tla. Vremenske prilike u vegetaciji (IV-IX) su bile nepovoljne te je palo 156, 2 mm oborina manje od višegodišnjeg prosjeka (377, 8 mm) dok je prosječna temperatura bila za 1, 9°C viša od višegodišnjeg prosjeka. Različit način obrade tla je imao statistički značajan utjecaj (p=0, 05) na masu 1000 zrna, dok statistički opravdane razlike nisu utvrđene u broju biljaka po jedinici površine, hektolitarskoj masi i prinosu zrna soje.

Cilj dvogodišnjeg istraživanja (2008./2009. – 2009./2010.) provedenog u Istočnoj Hrvatskoj bio je procijeniti pogodnost ozime pšenice – P (Triticum aestivum L.), raži - R (Secale cereale L.), facelije – F (Phacelia tanaceƟ folia L.), stočnog graška – Sg (Pisum arvense L.) i ozime grahorice – Vic (Vicia villosa L.) kao ozimih pokrovnih usjeva u poljskom pokusu koji je postavljen kao potpuno slučajni blok raspored u čeƟ ri ponavljanja. Pogodnost biljnih vrsta procijenjena je utvrđivanjem sklopa, nadzemne biomase i sadržaja usvojenog dušika u biljkama. Najpogodnijim biljnim vrstama koje se mogu koristiti kao ozimi pokrovni usjevi pokazale su se ozima pšenica s najvećim ostvarenim sklopom biljaka (542 m-2) što je čini pogodnom kulturom za brzu i učinkovitu pokrovnost tla, raž s najvećom ostvarenom nadzemnom biomasom (445 g m-2ST) u svrhu inkorporacije što veće količine organske tvari u tlo i ozima grahorica s najvećim sadržajem usvojenog dušika (13, 22 g m-2) čime pridonosi povećanju sadržaja ovog hraniva u tlu.

Slavoniji, za cilj su imala utvrditi utjecaj konzervacijskih sustava obrade tla i gnojidbe dušikom na visinu poljoprivrednog i biološkog prinosa te na žetveni indeks, u odnosu na konvencionalni sustav obrade. Primjenom konzervacijskih sustava obrade tla u uzgoju ozime pšenice i kukuruza ostvareni su ujednačeni prinosi (osim na no-till tretmanu u uzgoju kukuruza gdje je izmjeren značajno niži prinos) koji se nisu razlikovali u odnosu na konvencionalni sustav obrade tla. Gnojidba dušikom značajno je utjecala na sve ispitivane pokazatelje produktivnosti istraživanih usjeva, osim na žetveni indeks kukuruza. Razlike u visini poljoprivrednog i biološkog prinosa kod pšenice i kukuruza na tretmanima optimalne i prekomjerne gnojidbe nisu bile značajne, dok su na tretmanu s reduciranom gnojidbom izmjerene značajno niže vrijednosti . Dobiveni rezultati ukazuju na mogućnost potpune zamjene konvencionalnih sustava obrade tla u uzgoju kukuruza i ozime pšenice nekim od konzervacijskih sustava čime se smanjuje degradacija tla uz ostvarivanje visokih i stabilnih prinosa.

Stationary field experiment was set up in 2009 at two experimental stations and two different soil types in eastern Croatia, Stagnosol and Gleysol soil type. The aim of this research was to study the effects of different conservation soil tillage systems and nitrogen fertilization on yield and chemical composition of maize grain. Soil tillage and nitrogen fertilization significantly affected the chemical composition of maize grain.

The field experiments were carried out near Poljanci, Croatia, during summers 2015 and 2016. Treatments of soil tillage were as follows: MD) one passage with heavy disk harrow and SD) single passage by heavy disk harrow. Sub-treatments of side-dressing were as follows: C) no-sidedressing control ; B) Biological foliar fertilizer (Condi agro), with several aerobic and anaerobic microorganisms, including bacteria, actinomycetes, yeasts and mildews ; and M) Mineral foliar fertilizer (EcoTop Folimax) which contains both macro and micro nutrients. Ten sorghum cultivars were used: KSH3723, KSH3724, Lemnos, Leonie, Merlin, Sammos, Santos, Sole, Tarzan and Zerberus. The present study suggests better effects with foliar fertilizers in comparison with control, regardless of used soil tillage preparation. The results indicate several cultivars (Leonie, Lemnos and KSH3724) which can be used as successful summer catch crops after winter barley.