This study was conducted (2010–2012) to analyse the efficiency of irrigation scheduling in maize production based on soil moisture measurements (Watermark soil moisture sensors) in years with extreme weather events at the research site of the Agricultural Institute in Osijek, eastern Croatia. Three irrigation treatments and four maize hybrids were studied. In the extremely rainy 2010, the highest yield of maize grain was obtained in rainfed plots (control = 9.24 t ha−1). A significantly (P < 0.01) lower yield (−8%) was obtained in fully irrigated plots (a3 = 8.59 t ha−1). This was opposite to the results obtained from the extremely warm 2011 and very dry 2012, when grain yield was higher as the amount of irrigation water was increased. Maize grain yield in the fully irrigated plot was 25% (2011) and 40% (2012) higher compared with the control plots (dryland). According to our results, the main factor for irrigation efficiency in extreme weather conditions is to properly determine the optimum level for soil moisture sensors and ground water level in relation to root depth.

Sugar beet fertilization is a very complex agrotechnical measure for farmers. The main reason is that technological quality is equally important as sugar beet yield, but the increment of the root yield does not follow the root quality. Technological quality implies the concentration of sucrose in the root and the possibility of its extraction in the production of white table sugar. The great variability of agroecological factors that directly affect root yield and quality are possible good agrotechnics, primarily by minimizing fertilization. It should be considered that for sugar beet, the status of a single plant available nutrient in the soil is more important than the total amounts of nutrients in the soil. Soil analysis will show us the amount of free nutrients, the degree of soil acidity and the status of individual elements in the soil so that farmers can make a compensation plan. An estimate of the mineralizing ability of the soil, the N min, is very important in determining the amount of mineral nitrogen that the plant can absorb for high root yield and good technological quality. The amount of N needed by the sugar beet crop to be grown is an important factor, and it will always will be in the focus for the producers, especially from the aspect of trying to reduce the N input in agricultural production to preserve soils and their biodiversity but also to establish high yields and quality.

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A stationary field experiment of a reduced soil tillage was implemented at a Hypogley (Hypogleyic soils A–Gso–Gr soil horizon sequence) soil type of Eastern Croatia during three seasons and set up as a split-plot randomized block design in four repetitions. The tillage systems (TS) were as follows: 1) conventional tillage, i.e., plowing at 30 cm (CT), 2) disking up 10-12 cm (DT), 3) soil loosening up to 35 cm (LT), 4) no-tillage (NT). The experiment was designed to compare the penetration resistance (PR), soil moisture (SM), and bulk density (BD) at different TSs and soil depths. A cone penetrometer was used to measure the PR with 10 prods per TS, accompanied with a measurement of SM with a soil auger on every 10 cm, with four samples up to a 40-cm depth. The BD was determined by metal cylinders on every 10 cm up to a 30-cm depth, being weighed and dried thereafter to obtain an absolutely dry sample, and then calculated using absolutely a dry soil sample mass (m_s) and the soil volume (V). The PR and SM were significantly influenced by the TS and soil depth. The CT had the significantly lowest PR at all depths, while the DT has manifested a significantly higher PR at a soil depth amounting to 10 to 20 cm. The PR on NT were significantly diverse from the CT at all soil depths. The BD varied significantly concerning the TS and the soil depth. Subsequent to the three years, the CT had a significantly smaller BD at a depth amounting from 0 to 10 cm, and a significantly higher BD at 20- to 30-cm depth, compared to reduce the TS.

Soil texture is a vital criterion in most cropland suitability analyses, so an accurate method for the delineation of soil texture suitability zones is necessary. In this study, an automated method was developed and evaluated for the delineation of these zones for soybean cultivation. A total of 255 soil samples were collected in the Continental biogeoregion of Croatia. Three methods for interpolation of clay, silt and sand soil content were evaluated using the split-sample method in five independent random repetitions. An automated algorithm for soil texture classification based on the United States Department of Agriculture (USDA) in 12 classes was performed using Python script. Suitability classes for soybean cultivation per soil texture class were determined according to previous agronomic and soybean land suitability studies. Ordinary kriging produced the highest accuracy of tested interpolation methods for clay, silt and sand. Highly suitable soil texture classes for soybean cultivation, loam and clay loam, were detected in the northern part of the study area, covering 5.73% of the study area. The analysis of classification results per interpolation method indicated a necessity of the evaluation of interpolation methods as their performance depended on the normality and stationarity of input samples.

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Poljoprivredna proizvodnja u Hrvatskoj, općenito, ima važan značaj pri čemu biljna proizvodnja čini više od 50% ukupne poljoprivredne bruto proizvodnje. Najveću ulogu imaju žitarice i uljarice čija proizvodnja dominira u Panonskoj regiji s naglaskom na njen istočni dio. Cilj ovog rada je prikazati zasijane površine, ostvarenu proizvodnju i vanjskotrgovinsku razmjenu kukuruza, pšenice, ječma, soje, suncokreta i uljane repice tijekom petnaestogodišnjeg razdoblja (2003. - 2017.) u Hrvatskoj. Od ukupnih obradivih površina u analiziranom razdoblju žitarice (kukuruz, pšenica i ječam) zauzimaju oko 60% obradivih površina, a uljarice (soja, suncokret i uljana repica) oko 13%. Analizom podataka utvrđen je trend smanjenja površina pod žitaricama, naročito kukuruza, dok su uljarice pokazale trend rasta pri čemu su površine soje i uljane repice u zadnje tri godine gotovo udvostručene. Pristupanje Republike Hrvatske jedinstvenom tržištu Europske unije pozitivno je utjecalo na povećanje neto izvoza žitarica i uljarica. Prosječni volumen neto izvoza žitarica i uljarica za pet godina članstva u EU se više nego utrostručio u odnosu na prosjek predpristupnog perioda promatranog od 2003. do 2013. godine. Domaće cijene žitarica i uljarica prate trendove cijena na jedinstvenom tržištu uz stabilan razvoj nakon ulaska Hrvatske u Europsku uniju.

During the 3‐year study, maize (Zea mays L.) production in the eastern Republic of Croatia suffered great losses due to periods of flood (2010) and drought (2011 and 2012). An excessive amount of water as well as lack of it caused variation of yield and efficiency of irrigation scheduling. Irrigation treatments included a rainfed treatment and irrigation up to soil water content 80–100% of field capacity. The nitrogen fertilization treatments were 0 (control) and 200 kg N ha−1. The analysed crop productivity parameters were 1000‐grain mass and grain yield, in two hybrids. The irrigation significantly increased maize grain yield in dry years, while in the extremely wet year of 2010 yield in the irrigated plot was reduced doe to stress caused by excessive rainfall and over‐irrigation. Both tested hybrids responded positively to the combination of nitrogen fertilizer and irrigation. Regardless of whether expressed on a fresh tissue or dry weight basis, the proline content in maize leaf did not show a clear effect of irrigation treatment, whereas nitrogen fertilization stimulated this amino acid accumulation. There was a close relationship established between proline in leaf dry matter in both growth stages and 1000‐grain mass, as well as a weak relationship between this parameter at flowering and final grain yield. Copyright © 2017 John Wiley & Sons, Ltd.