A Comparison of Precise Fertilization Prescription Rates to a Conventional Approach Based on the Open Source GIS Software

Fertilization is one of the most important components of precision agriculture, ensuring high and stable crop yields. The process of spatial interpolation of soil sample data is recognized as a reliable method of determining the prescription rates for precise fertilization. However, the application of a free open-source geographic information system (GIS) software was often overlooked in the process. In this study, a method of precise fertilization prescription map creation was developed using an open-source GIS software to enable a wider and cheaper availability of its application. The study area covered three independent locations in Osijek-Baranja County. A method was developed for the fertilization of sugar beet with phosphorous pentoxide, but its application is universal with regard to the crop type. An ordinary kriging was determined as an optimal interpolation method for spatial interpolation, with the mean RMSE of 1.8754 and R2of 0.6955. By comparing the precision fertilization prescription rates to a conventional approach, the differences of 4.1 kg ha-1 for Location 1, 15.8 kg ha-1 for Location 2, and 11.2 kg ha-1 for Location 3 were observed. These values indicate a general deficit in soil phosphorous pentoxide, and precise fertilization could ensure its optimal content in the future sowing seasons

Utjecaj koncentracije digestata prilikom uzgoja na kvalitetu bioplina dobivenoga anaerobnom digestacijom vodene leće (Spirodela polyrhiza)

Duckweed is a widespread type of tiny free-floating plants of the flowering class. A typical representative of the family of the cowhide (Lemnaceae) is a large duckweed (Spirodela polyrhiza) and it is very common on Croatian inland waters. Like all other species of duckweeds, it is characterized by the possibility of vegetative and sexual reproduction and very rapid growth. It has the ability to remove nitrogen, phosphorus and some heavy metals from the substrate and is considered a very desirable raw material for biogas production for several reasons. The necessity of reducing environmental pollution of nitrates from agricultural production and the ability to grow water lenses under eutrophic conditions have sparked this research. The primary objective of the study is to determine the possibilities of continuously growing large duckweed at different concentrations of digestates for the purpose of biogas production. The secondary goal is to determine the dependence between the different digestate concentrations used for the duckweed green mass production and the quantity and quality of the biogas obtained through the anaerobic digestion process at thermophilic conditions.Vodena leća je široko rasprostranjena vrsta sitnih slobodno plivajućih biljaka iz razreda cvjetnica. Tipičan predstavnik porodice kozlačevki (Lemnaceae) je velika vodena leća (Spirodela polyrhiza) i vrlo je česta na vodenim površinama kontinentalne Hrvatske. Kao i sve ostale vrste vodenih leća, karakterizira ju mogućnost vegetativnoga i spolnog razmnožavanja te vrlo brz rast. Smatra se vrlo poželjnom sirovinom za proizvodnju bioplina iz nekoliko razloga. Nužnost smanjenja zagađenja okoliša nitratima iz poljoprivredne proizvodnje te sposobnost rasta vodenih leća u eutrofnim uvjetima potaknuli su ovo istraživanje. Primarni cilj istraživanja jest utvrditi mogućnosti kontinuiranoga uzgoja velike vodene leće na različitim koncentracijama digestata, sa ciljem proizvodnje bioplina. Sekundarni je cilj utvrditi zavisnost između različitih koncentracija digestata korištenih za proizvodnju zelene mase vodene leće te kvantitete i kvalitete bioplina dobivenog postupkom anaerobne digestije pri termofilnim uvjetima

Prinos zelene mase, sjemena i ostalih komponenata uroda stočnog graška (Pisum sativum L.) u zavisnosti od agroekoloških uvjeta i starosti sjemena

The goal of the research was to determine the influence of two locations (Osijek and Vinkovci) and seed age on field germination, vegetative mass and dry matter of vegetative mass yields, grain yield, 1000 grain weight and grain crude protein yield of foreign spring field pea cultivar (Timo) during two successive years (2004 and 2005). The year has significantly influenced the grain yield, and the location influenced the grain yield and 1000 grain weight. In the first year of research, the greater grain yield by 70 % was accomplished on Osijek location, and in the second year it almost doubled. 1000 grain weight was by 19 % greater in the second year of research on Osijek location in relation to Vinkovci location. The same cultivar seed stored for 9 and 21 months were sown on both locations in the second year of investigation. Field germination of 9 month old seed was for 12.1 % greater than 21 month old seed. Seed maturity and location interaction was significant (p=0.05) for vegetative mass yield, dry matter of vegetative mass yield, grain yield and grain crude protein yield.Tijekom 2004. i 2005. godine istraživan je utjecaj agroekoloških uvjeta i starosti sjemena na poljsko nicanje, prinos zelene mase i suhe tvari nadzemne vegetativne mase, prinos zrna, masu 1000 zrna i prinos sirovih bjelančevina zrna inozemnog jarog stočnog kultivara graška (Timo) na dvije lokacije istočne Hrvatske (Osijek i Vinkovci). Godina je značajno utjecala na prinos zrna, a lokacija na prinos i masu 1000 zrna. U prvoj godini istraživanja ostvaren je za 70 % viši prinos zrna na lokaciji Vinkovci, dok je u drugoj godini gotovo dvostruko viši prinos zrna ostvaren na lokaciji Osijek. Masa 1000 zrna u drugoj godini istraživanja bila je za 19 % veća na lokaciji Osijek, a interakcija godine i lokacije značajna. Sjeme istog kultivara skladišteno 9 i 21 mjesec posijano je na obje lokacije u drugoj godini istraživanja. Poljsko nicanje sjemena starog 9 mjeseci bilo je za 12,1 % više od poljskog nicanja sjemena starog 21 mjesec na obje lokacije. Interakcija starosti sjemena i lokacije bila je značajna (p=0,05) za prinos zelene mase i suhe tvari nadzemne vegetativne mase, prinos zrna, te prinos sirovih bjelančevina zrna

EFEKT NAVODNJAVANJA I GNOJIDBE DUŠIKOM NA PRINOS SJEMENA SOJE S KORELACIJOM U ODNOSU NA KONCENTRACIJU BJELANČEVINA I ULJA

The paper presents the result of a triennial field experiment (2013‒15), aiming to determine the influence of irrigation, nitrogen fertilization, and cultivars, as well as their interactions on the yield and chemical properties of the soybean seeds. Four soybean cultivars (Lucija, Vita, Ika and Tena) of different maturity groups were investigate as a sub‐subplot factor (C). The main plot factor (A - irrigation) resulted in a statistically very significant (P≤0.01) seed yield in all three years, and it was found out by an analysis of variance. The subplot factor (B - nitrogen fertilization) had an impact on the grain yield depending on the research year, while sub‐subplot factor (C-cultivar) significantly affected all examined traits. The factor interactions and their significance varied by the research years. The seed yield achieved in 2013 (3883 kg ha-1) indicated a great importance of all factors’ interaction. The correlations between a seed yield and a protein and oil concentration were determined during the research.U radu su prikazani rezultati trogodišnjih poljskih pokusa (2013. – 2015.), s ciljem utvrđivanja utjecaja navodnjavanja, gnojidbe dušikom i sorte te njihove interakcije na prinos i kemijska svojstva zrna soje. Ispitivane su četiri sorte soje (Lucija, Vita, Ika i Tena) različitih grupa zriobe kao pod‐podčimbenik (C). Analizom varijance utvrđeno je da se glavni čimbenik (A – navodnjavanje) statistički vrlo značajno (P≤0,01) odrazio na prinos zrna u svima trima godinama. Podčimbenik (B – gnojidba dušikom) imao je utjecaja na prinos zrna zavisno o godini istraživanja, dok je pod‐podčimbenik (C – sorta) značajno utjecao na sva ispitivana svojstva. Interakcije čimbenika i njihova značajnost razlikovale su se prema godini istraživanja. Ostvareni prinos zrna u 2013. godini (3883 kg ha-1) ukazuje na veliko značenje međusobnoga djelovanja svih čimbenika. Tijekom istraživanja utvrđene su korelacije između prinosa sjemena i koncentracije bjelančevina i ulja

ECONOMICS OF CABBAGE CULTIVATION ON THE FAMILY FARM

Istraživanja o nekim tehnološkim aspektima i ekonomici (ekonomskim pokazateljima proizvodnje) obavljena su tijekom 2012. godine na površinama obiteljskog poljoprivrednog gospodarstva (OPG) u Punitovcima u Osječko-baranjskoj županiji. Na parceli od 1 ha praćeni su i evidentirani neki agrotehnički zahvati, organizacijski aspekti i ekonomika proizvodnje kupusa. Uzgajani je kasni hibrid Bravo F1. Sjetva kupusa obavljena je sredinom svibnja u tunelima prekrivenim plastičnom folijom. Temeljem prikupljenih podataka izrađena je tehnološka karta a izračunate su i norme. Provedena je ekonomska analiza proizvodnje kupusa koja je pokazala dobar financijski rezultat. Troškovi proizvodnje od 47.812,26 kn ha-1 uz njezinu vrijednost od 63.000,00 kn ha-1 doveli su do dobiti od 15.187,74 kn ha-1. To je za uvjete proizvodnje na otvorenom i provedenim ulaganjima isplativa proizvodnja.Studies on some technological aspects and economics (economic indicators of production) were carried out during 2012 on a family farm (OPG) in Punitovci, the Osijek - Baranja County. Some agrotechnical practices, organizational aspects and economics of cabbage production were monitored and recorded on the plot of 1 ha. Cabbage late hybrid Bravo F1 was cultivated. Sowing cabbage was conducted in mid-May in tunnels covered with plastic wrap. Based on the collected data the technological map was made and the norm calculated. Economic analysis of cabbage production was conducted and it showed good financial results. Production costs of 47.812,26 HRK per ha-1 with the production value of 63.000.00 HRK per ha-1 led to a profit of 15.187,74 HRK per ha-1. That is a profitable production for the production conditions on the open and the investments

ECONOMICS AND PRODUCTION OF PEPPER (Capsicum annuum L.) ON THE FAMILY FARM ĐAMBIĆ FROM ĐAKOVO

Za potrebe ovoga rada obavljena su istraživanja tijekom 2009. godine na obiteljskom poljoprivrednom gospodarstvu Đambić u Širokom Polju. Na površini od jednog hektara praćeni su i evidentirani agrotehnički zahvati, tehnologija i organizacija uzgoja začinske paprike. Na temelju prikupljenih podataka, izračunatih normi i izrađene tehnološke karte utvrđen je utrošak od 41,5 sati rada strojeva i 950,74 sati rada ljudi po hektaru. Podatci pokazuju da je proizvodnja radno intenzivna s velikim utroškom ljudskog rada. Ukupni troškovi iznose 41.174,80 kn, a uz prinos od 1 t ha-1 i vrijednost proizvodnje od 70.000,00 kn, ostvarena dobit je 28.825,20 kn. Na temelju koeficijenta ekonomičnosti proizvodnje od 1,70 utvrđeno je da je proizvodnja začinske paprike ekonomična, a na 100 kn uloženih u proizvodnju ostvareno je 70 kn dobiti.For purposes of this research work was carried out during 2009 on the family farm Đambić at Široko Polje. The area of one hectare was monitored and agricultural operations, technology and organization of growing condiment peppers recorded. Based on the data collected, calculation and made technological norms the consumption of 41.5 hours machine work and 950.74 hours of labor people per hectare were established. The data show that the production was labor intensive with large expenditure of human labor. Total costs amounted to 41174.80 HRK, with the yield of 1 t ha-1 and the output value of 70000.00 HRK, the operating profit was 28825.20 HRK. On the basis of production efficiency coefficient of 1.70 it was determined that the production of pepper was profitable, and the 100 HRK invested in the production realized 70 HRK profit

Potential of widespread floating aquatic plants of Bosut River in biogas production

Cilj istraživanja je utvrditi prinos bioplina i metana iz gnojovke s dodatkom tri vrste vodenih biljaka (Spirodela polyrhiza, Azolla caroliniana i Lemna minor). Uzgoj tradicionalno korištenih biljaka (npr. kukuruz, uljana repica) za dobivanje biogoriva zahtijeva obradive površine, dok se vodene biljke, kao alternativa, mogu prikupiti iz prirode, a zbog jednostavne građe, brzine rasta i povoljnog kemijskog sastava mogu se bez pred-tretmana koristiti kao osnovna ili dopunska sirovina u bioplinskim postrojenjima. Četiri uzorka (kontrola i tri vrste vodenih biljaka) u tri ponavljanja povrgnuta su anaerobnoj digestiji. Različite vrste proizvode različite količine bioplina u odnosu na kontrolu (od 504,83 do 881,62 mL g-1 S.T.). Udio dobivenog metana iznosi od 57,96 do 60,63 % u zavisnosti od biljne vrste. Ovo ukazuje na izuzetan potencijal korištenja ovih vrsta za dobivanje bioplina i metana.The aim of the study is to determine the yield of biogas and methane from slurry with the addition of three species of aquatic plants (Spirodela polyrhiza,Azolla caroliniana and Lemna ninor). Cultivation of traditionally used plants (eg.corn, oilseed rape) to produce biofuels requires arable land, while aquatic plants,as an alternative, can be collected from nature, and due to simple structure, growth rate and favorable chemical composition, they can be used as a primary or supplementary raw material in biogas plants without any pre-treatment. Four samples (control and three aquatic plant species) in three replicates were subjected to anaerobic digestion. Different species produce different amounts of biogas compared to the control (from 504.83 to 881.62 mL g-1 DM). The methane content is from 57.96 to 60.63% depending on the plant species. This indicates the tremendous potential of using these species of aquatic plants to produce biogas and methane