Crop Yield and Plant Density under Different Tillage Systems

To determine the optimal ploughing depth and to make tillage simpler and less costly, but also taking account of edaphic and climatic conditions as well as biological and agrotechnical requirements of crops grown, long-term investigations (1994-2009) have been carried out on Stagnic Luvisol of sloping terrains in central Croatia near Daruvar. The paper presents the results relating to plant density and yields of maize (Zea mays L.), soybean (Glycine max L.), oilseed rape (Brassica napus L.), winter wheat (Triticum aestivum L.) and spring barley (Hordeum vulgare L.). Investigation results point to the conclusion that high density crops (winter wheat, spring barley and oilseed rape) are suitable for growing under reduced tillage systems. Yields of low density spring crops (maize and soybean) obtained under the no-tillage system are not satisfactory, especially in climatically extreme years

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

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

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

Effect of Soil Physical State on the Earthworms in Hungary

Hungarian authors have long been discussing the role of earthworms in improving soil productivity. Earthworm counts in our higher quality soils are similar to those found in soils where more attention is paid to earthworm activity. Negative impacts that are independent of farming—such as sustained dry spells in the summer—also affect earthworm counts. Negative impacts that definitely depend on farming include land use causing soil moisture loss, deep stubble treatment leaving the soil without cover, and ploughing in the summer without subsequent pressing. The climate change is having both positive and negative impacts. Weather patterns are causing losses but adopting climate mitigating tillage are generating benefits. In the trials results so far show that tillage focusing on preserving soil moisture, structure, and organic materials, covering the surface in the critical months as well as adequate soil loosening are fundamental pre-requisites for making the soil a favourable habitat for earthworms

Threats to Sustainability of Soil Functions in Central and Southeast Europe

A diverse topography along with deforestation, changing climatic conditions, long-term human settlement, overuse of agricultural lands without sustainable planning, cultural difficulties in accepting conservative land management practices, and wrong political decisions have increased the vulnerability of many soils to degradation and resulted in a serious decline in their functional capacity. A progressive reduction in the capacity of soils to support plant productivity is not only a threat in the African continent and its large desert zone, but also in several parts of Central and Southeastern Europe (CASEE). The loss of soil functions throughout CASEE is mainly related to the human activities that have profound influence on soil dynamic characteristics. Improper management of soils has made them more vulnerable to degradation through water and wind erosion, organic matter depletion, salinity, acidification, crusting and sealing, and compaction. Unmitigated degradation has substantial implications for long term sustainability of the soils’ capability to support human communities and resist desertification. If sustainable agricultural and land management practices are not identified, well understood and implemented, the decline in soil quality will continue and probably accelerate. The lack of uniform criteria for the assessment and evaluation of soil quality in CASEE countries prevents scientific assessments to determine if existing management practices are leading to soil quality improvement, or if not, what management practices should be recommended to mitigate and reverse the loss of soil health