Strategies of Growing Several Sorghum Cultivars as a Post-Harvest Crop in North-Eastern Croatia Condition

Recent climate changes lead toward possibility of using longer period of higher temperatures after winter crops harvest for establishing post-harvest crop, such is sorghum. It can produce significant biomass, useful both for feed and bioenergy, even in drier summers, with reduced soil tillage preparation. The trial was set up in Poljanci, Croatia, in years 2015 and 2016 as a split-plot design with foliar fertilizers and sorghum cultivars treatments, established by diskharrowing soil after winter wheat harvest in mid-July, and harvested before autumn frosts at the end of November. Foliar fertilizers treatments were C) Control (no fertilization), B) Biological (Condi agro) and M) Mineral (EcoTop Folimax) foliar fertilizers. Cultivars used in trial were KSH3723, KSH3724, Lemnos, Leonie, Merlin, Sammos, Santos, Sole, Tarzan and Zerberus. Foliar fertilizer treatments B and M showed higher dried biomass yield for 7 and 11% in comparison with C, respectively. Difference between treatments were higher at fresh biomass yield. Treatments B and M showed 12 and 22% higher fresh biomass yield than C, respectively. Regarding the tested sorghum cultivars, the highest fresh biomass yield was recorded for Leonie (32933 kg ha-1), followed by Lemnos (27467 kg ha-1) and KSH3724 (26600 kg ha-1), whereas the lowest yield was recorded for Zerberus (19600 kg ha-1)

EKONOMSKA ODRŽIVOST PRIMJENE POSTRNIH USJEVA U EKOLOŠKOM UZGOJU KUKURUZA

Although organic crop production has numerous advantages, concerns about economic sustainability, both environmental and financial, make farmers reluctant to convert their conventional production into the organic production. Certain agricultural methods, such as second crop use, can alleviate some problems regarding soil tilth, erosion prevention, nutrients availability and weed control, thus contributing toward more sustainable crop production. Also, the added value crop growth, such as maize (Zea mais L.) hybrid\u27s parental line production, with lower yields but higher prices, can contribute to sustainability of organic production. In order to test the hypothesis that the use of second crops can contribute toward the sustainability of organically grown maize after soybean (Glycine max L.) as a previous crop in the crop rotation, the experimental site was established in Valpovo, Croatia, in the eutric brown soil type, during the years 2005 and 2006. The experimental design was set up as a CRBD in four repetitions, with six second crop treatments: CT – Control, without second crop; WW – winter wheat (Triticum aestivum L.) second crop; RY – rye (Secale cereale L.) second crop; FP – fodder pea (Pisum arvense L.) second crop; WP – mixture of WW and FP; and RP – mixture of RY and FP. In order to assess the soil surface protection and evaluate the weed suppression, the second crop coverage had been recorded. Regarding the economic sustainability, the second crop use depending costs were analysed in relation to the extra produced maize yield. The RY treatment had the highest profitability, followed by WW, RP and O. The WP and FP revealed lower relative profitability than O, thus presenting the evidence of sustainability risk of these treatments.Premda ekološka poljoprivreda ima brojnih prednosti, zabrinutost zbog održivosti, i ekološke i ekonomske, farmere često odvraća od prijelaza s konvencionalne proizvodnje na ekološku. Intenzifikacijom plodoreda uporabom postrnih usjeva, mogu ukloniti neke probleme vezane za ugorenost tla, prevenciju erozije, dostupnost hraniva i suzbijanje korova, doprinoseći na taj način održivosti proizvodnje usjeva. Također, uzgoj usjeva s dodatnom vrijednošću, kao što su roditeljske linije za proizvodnju hibrida kukuruza (Zea mais L.), s nižim prinosima ali višom cijenom, može pridonijeti održivosti (profitabilnosti) ekološke proizvodnje. U namjeri da se potvrdi hipoteza da postrni usjevi mogu doprinijeti održivosti ekološkog uzgoja kukuruza u dvopoljnom plodoredu sa sojom (Glycine max L.) kao prethodnim usjevom, postavljeno je pokušalište u Valpovu, Hrvatska, na eutričnom smeđem tlu, tijekom 2005. i 2006. godine. Pokus je postavljen kao potpuno slučajan blok raspored u četiri ponavljanja, sa šest tretmana postrnih usjeva: CT – kontrola, bez postrnih usjeva; WW – ozima pšenica (Triticum aestivum L.); RY – ozima raž (Secale cereale L.); FP – stočni grašak (Pisum arvense L.); WP – smjesa WW i FP; te RP – smjesa RY i FP. U cilju određivanja zaštite površine tla i evaluacije suzbijanja korova, zabilježena je pokrivenost postrnim usjevima. Glede isplativosti, analizirani su relativni troškovi upotrebe postrnih usjeva u odnosu na dodatno proizvedeni urod kukuruza. RY tretman je zabilježio najvišu profitabilnost, a pratili su ga tretmani WW, RP i O. Tretmani WP i FP pokazali su se manje profitabilni od O, time pružajući dokaze o rizičnoj održivosti ovih tretmana

USPOREDBA DVA SUSTAVA OBRADE TLA ZA OZIMI JEČAM I SOJU S KORIŠTENJEM DUŠIKA SAMO IZ REZIDUA SOJE

The winter barley crop growing has not been adequately researched regarding soil tillage systems, especially in crop rotation with the soybean, both crops gaining importance as food or fodder. Also, productivity of such crop rotation in low nitrogen environment is especially interesting for organic crop growing, where mineral nitrogen fertilization is not allowed. The research on two soil tillage systems, the conventional one, based on mouldboard ploughing (PLOW) and reduced soil tillage, based on discharrowing (DISC), with no other nitrogen source except symbiotic soybean bacterial fixation, was conducted at the experimental site Bokšić (Croatia), during the seasons 2004/05 and 2005/06. Results showed low but stable yields of winter barley, between 2.1 and 2.6 t ha-1, where PLOW treatment recorded lower yield than DISC in 2005, and usual soybean yields (between 2.8 and 3.4 t ha-1), with higher soybean grain yields for PLOW only in 2006. The absolute mass and hectolitre mass did not show any statistical differences among treatments either.Uzgoj ozimog ječma nije adekvatno istražen glede sustava obrade tla, posebice u plodoredu sa sojom, a oba usjeva dobivaju na važnosti kao hrana za ljude ili krma za životinje. Isto tako, produktivnost ovakvog plodoreda u uvjetima niske gnojidbe dušikom je osobito zanimljiva za ekološku poljoprivredu, gdje korištenje mineralnih dušičnih gnojiva nije dopušteno. Istraživanje dvaju sustava obrade tla, konvencionalnog, baziranog na oranju lemešnim plugom (PLOW), te reduciranog, baziranog na tanjuranju (DISC), bez ikakvog izvora dušika osim dušika simbiotski vezanog kvržičnim bakterijama na soji, provedeno je na pokušalištu Bokšić (Hrvatska), tijekom sezona 2004/05-2005/06. Rezultati su pokazali niske ali stabilne urode ozimog ječma, između 2.1 i 2.6 t ha-1, gdje je na PLOW tretmanu zabilježen niži prinos nego na DISC tretmanu u 2005. godini, te uobičajene urode soje (između 2.8 i 3.4 t ha-1), s višim urodima zrna soje na PLOW tretmanu samo u 2006. godini. Razlike apsolutne i hektolitarske mase među tretmanima nisu bile statistički opravdane

Cover crops in conservation agriculture

Konzervacijska poljoprivreda sa svojim temeljnim principima (trajna pokrovnost tla, minimalna obrada i plodored) jedan je od najučinkovitijih sustava za prilagodbu poljoprivredne proizvodnje nepovoljnim uvjetima klimatskih promjena. Brojne prednosti konzervacijske poljoprivrede dodatno su izražene integracijom pokrovnih usjeva u plodored. Pokrovni usjevi uvode se u inovativne sustave biljne proizvodnje u svrhu poboljšanja kemijskih, fizikalnih i bioloških svojstava tla uz pozitivan utjecaj na bioraznolikost i doprinos održivosti poljoprivredne proizvodnje. Cilj ovoga rada je pregledno prikazati neke od glavnih uloga pokrovnih usjeva u konzervacijskoj poljoprivredi s osvrtom na zaštitu tla od erozije, konzervaciju vode i hraniva te utjecaj na organsku tvar i strukturu tla.Conservation agriculture with its basic principles (permanent soil cover, minimal soil disturbance and crop rotation) is one of the most effective tools for adapting agricultural production to the adverse conditions of climate change. The numerous advantages of conservation agriculture are further expressed by the integration of cover crops into the crop rotation. Cover crops are introduced into innovative plant production systems for the purpose of improving the chemical, physical and biological properties of the soil with a positive impact on biodiversity and contributing to the sustainability of agricultural production. The aim of this paper is to present some of the main roles of cover crops in conservation agriculture with emphasis on soil erosion protection, water and nutrient conservation, and the impact on organic matter and soil structure

UTJECAJ POSTRNIH USJEVA NA PRINOS I KOMPONENTE PRINOSA U EKOLOŠKOM UZGOJU KUKURUZA

The second crop use in organic agriculture is a known method of maintaining the soil tilth, soil protection against environmental deterioration, soil nutrients conservation and even the weed control. The nitrogen conservation from previous leguminose crop is even more important, especially in the organic agriculture where use of N-fertilizers is the strictly forbiden, and second crops can be used as a catch crops for nutrients in rotation prior to the crops with the high N requirement. The choice of the proper second crop has, however, been insufficiently investigated, especially for agri-environmental conditions of the Panonian agricultural area in Croatia. The second crop experiment was established in Valpovo, Croatia, in the eutric brown soil type, during the years 2005 and 2006. The aim of the experiment was to investigate the effects of different second crops and their combinations on maize (Zea mais L.) yield and yield components in organic agriculture after soybean (Glycine max L.) in crop rotation. The experimental design was set up as a CRBD in four repetitions, with soybean as a previous crop in crop rotation. The six second crop treatments were: O – Control, without second crop; WW – winter wheat (Triticum aestivum L.) second crop; RY – rye (Secale cereale L.) second crop; FP – fodder pea (Pisum arvense L.) second crop; WP – mixture of the WW and FP; and RP – mixture of RY and FP. The WW treatment had the highest second crop dry mass, whereas FP had the lowest dry mass. The highest plant density was recorded for FP, and it was higher than the RP plant density, which also had the lowest plant height. The achieved maize yields were the highest for RY, but they were not significanlty different from the O, RP, and WW treatments. However, the yield achieved by RY treatment was significantly higher than the yields recorded for WP and FP treatments. The absolute mass and hectolitre mass did not show any statistical differences among treatments.Upotreba postrnih usjeva u ekološkoj/organskoj poljoprivredi je priznata metoda za održavanje ugorenosti tla, zaštite tla protiv vremenskih neprilika, konzervacije hraniva u tlu te čak i borbe protiv korova. Konzervacija dušika od prethodnog leguminoznog usjeva je čak važnija funkcija, posebice u ekološkoj poljoprivredi gdje je upotreba mineralnih dušičnih gnojiva izrijekom zabranjena, te postrni usjevi mogu poslužiti za čuvanje dušika od ispiranja iz tla za sljedeći usjev u plodoredu s visokim zahtjevima za dušikom. Nažalost, izbor postrnih usjeva nije dostatno istražen, posebice za agroekološke uvjete u Hrvatskoj. Stoga je postavljen pokus u Valpovu, Republika Hrvatska, na eutričnom smeđem tlu, tijekom 2005. i 2006. godine, s ciljem da se istraže učinci različitih postrnih usjeva i njihovih kombinacija na komponente prinosa i prinos kukuruza (Zea mais L.) u ekološkoj (organskoj) poljoprivredi, a u plodoredu iza predusjeva soje (Glycine max L.). Pokus je postavljen kao potpuno slučajan blok raspored u četiri repeticije, sa šest tretmana postrnih usjeva: CT – kontrola, bez postrnih usjeva; WW – ozima pšenica (Triticum aestivum L.); RY – ozima raž (Secale cereale L.); FP – stočni grašak (Pisum arvense L.); WP – mješavina WW i FP; te RP – mješavina RY i FP. WW tretman imao je najveću masu postrnih usjeva, dok je FP imao najmanju masu postrnih usjeva. Najgušći sklop zabilježen je na FP tretmanu, značajno viši nego sklop na RP tretmanu, koji je također imao i najnižu visinu stabljika usjeva kukuruza. Ostvareni prinosi kukuruza bili su najviši na RY tretmanu, no nisu bili signifi-kantno različiti od O, RP i WW tretmana. Ipak, prinos zabilježen na RY tretmanu bio je signifikantno viši od prinosa na WP i FP tretma-nima. Apsolutna i hektolitarska masa nije se statistički razlikovala između tretmana

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

Effects of Biochar and Sugar Factory Lime Application on Soil Reaction in Acidic Soils

Soil reaction, expressed as a pH value, is an indicator of acidity or alkalinity. The soil acidic reaction causes increased mobility of aluminium in the soil and can have negative effects on root growth. Plants grow and develop in soils of different soil reactions, but the optimum soil reaction is between slightly alkaline and slightly acidic. The aim of this research was to determine the impacts differences between the effects of biochar and sugar factory waste lime on soil reaction in acid soils. The research was carried out on stationary field trials at two locations on acid soils in Osijek-Baranja and Virovitica-Podravina County, Croatia. The treatments were: C - control, B1 - 5 t ha-1, B2 - 10 t ha-1, B3 - 15 t ha-1 of biochar and L optimal dose of sugar factory waste lime that was calculated for each field trial location. Two steps of sub factors were also applied, F0 - without fertilization and F1 – with recommended fertilization. Soil samples were taken in V3 and silking stages of maize growth from 0-25 cm. The average soil pH value in V3 stage of maize growth was 5.42 and in silking was 5.93. The highest pH values in both stages of maize growth were measured in treatment with liming. The lowest hydrolytic acidity was measured at the liming treatment, while all other treatments had a significantly higher value compared to lime. sugar factory lime is optimal conditioner if we want fast and cheap raise in soil pH values, but it must be noted that together with liming we usually must implement many other soil restauration measures, like humization, especially in degraded soils. Key words: biochar, sugar factory waste lime, acid soil, soil restauration measures, soil reactio

Effects of Biochar and Sugar Factory Lime Application on Soil Reaction in Acidic Soils

Soil reaction, expressed as a pH value, is an indicator of acidity or alkalinity. The soil acidic reaction causes increased mobility of aluminium in the soil and can have negative effects on root growth. Plants grow and develop in soils of different soil reactions, but the optimum soil reaction is between slightly alkaline and slightly acidic. The aim of this research was to determine the impacts differences between the effects of biochar and sugar factory waste lime on soil reaction in acid soils. The research was carried out on stationary field trials at two locations on acid soils in Osijek-Baranja and Virovitica-Podravina County, Croatia. The treatments were: C - control, B1 - 5 t ha-1, B2 - 10 t ha-1, B3 - 15 t ha-1 of biochar and L optimal dose of sugar factory waste lime that was calculated for each field trial location. Two steps of sub factors were also applied, F0 - without fertilization and F1 – with recommended fertilization. Soil samples were taken in V3 and silking stages of maize growth from 0-25 cm. The average soil pH value in V3 stage of maize growth was 5.42 and in silking was 5.93. The highest pH values in both stages of maize growth were measured in treatment with liming. The lowest hydrolytic acidity was measured at the liming treatment, while all other treatments had a significantly higher value compared to lime. sugar factory lime is optimal conditioner if we want fast and cheap raise in soil pH values, but it must be noted that together with liming we usually must implement many other soil restauration measures, like humization, especially in degraded soils. Key words: biochar, sugar factory waste lime, acid soil, soil restauration measures, soil reactio