Systems of conservation tillage in Europe

Neke znanstvene spoznaje, ali još više praktične opservacije i empirija stvorile su podlogu da se već krajem 19., a osobito u prvim desetljećima 20. stoljeća počne na nov način razmišljati o obradi tla kao tradicionalnom mehaničkom zahvatu u fizikalni kompleks neposredno, te kemijski i biološki posredno. Međutim, tek razvojem nekih prirodnih znanosti nakon drugog svjetskog rata, a osobito u posljednja dva desetljeća ispunile su se i praktične pretpostavke za realizaciju nekih, ranije nezamislivih koncepcija u uzgoju poljoprivrednih kultura. Time je ujedno stvorena osnova za diferencirani pristup u obradi tla. Kao logična posljedica toga javile su se i nove metode obrade tla unutar kojih konzervacijska odnosno reducirana obrada tla zauzima središnje mjesto. Nakon određenog provjeravanja putem egzaktnih znanstvenih istraživanja, ali i posvemašne empirije, nove metode obrade već su duboko zaživjele u praksi mnogih europskih zemalja, no s različitim uspjehom u različitim, često potpuno divergentnim ekološkim uvjetima. Ipak, mora se reći da su se one već duboko usadile i u psihu onih uzgajatelja bilja koji u novim trendovima obrade sagledavaju ne samo njene praktične aspekte, već i one znatno sofisticiranije koje u prvi plan stavljaju brigu za očuvanje ravnoteže stanišnih faktora unutar određenog agroekosustava. Ovaj rad i drugih pet radova koji se iznose bave se problemima konzervacijske obrade tla u najširem smislu riječi na području cijele Europe. U njemu se na osnovi brojnih znanstvenih publikacija prikupljenih od najpozva-nijih znanstvenika u ovom području u Europi daje osvrt na pravac, opseg i rezultate provedenih istraživanja. Uz razmatranje nekih općih pitanja obrade tla, posebno se pojmovno razmatra konzervacijska obrada tla, procjena pogodnosti tla za njezinu primjenu, stanje konzervacijske obrade tla u Europi i razvojne tendencije u minimalnoj obradi tla, uključujući obradu tla čizelom i "paraplugom". Konzervacijska obrada tla razmatra se i s nekih drugih aspekata – s aspekta utroška energije, primjene specijalnih sijačica u ovom sustavu obrade, sa stajališta suzbijanja korova, borbe protiv erozije, te promjena u fizikalnom, kemijskom i biološkom kompleksu tla s posebnim naglaskom na odnos konzervacijske obrade tla prema primjeni dušika i djelomično biljnim bolestima. Na kraju se daje osvrt na reaktivnost nekih važnijih oraničnih kultura na različite oblike konzervacijske obrade tla. Ovaj sustav obrade tla, pod pretpostavkom da se još istraže objektivno i s potrebnom pozornošću neke njegove specifične osobitosti u našim ekološkim uvjetima, trebao bi se sasvim udomaćiti u našoj proizvodnoj praksi ne samo kao zamjena vladajućim sustavima u ekvivalentnim odnosima, već dijelom i kao njihova nadopuna.At the end of the 19th century, but specially in the first decades of the 20th century, some scientific findings and, particularly, practical observation and experience, induced new ways of thinking about soil tillage, the traditional intervention directly into the physical and indirectly into the chemical and biological soil complex. However, it was only after the Second World War, notably in the last two decades, that advances in some natural sciences made it possible to implement some, earlier unconceivable, ideas on growing field crops. This constituted the basis for a different approach to soil tillage. As a consequence, new methods of soil tillage have been, among which conservation, that is reduced tillage is most important. After being tested by exact scientific investigations, as well as by practical experience, new methods have already become common practice in a number of European countries, where they are applied with different success in sometimes quite divergent ecological conditions. Nevertheless, it should be noted that they have became deeply rooted in the minds of those plant growers who do not regard new trends in soil tillage only from their practical aspects, but also from the more sophisticated aspect of preserving the balance of habitat factors within a particular ecosystem. This paper and the other five papers which are presented in this journal deal with the problems of conservation tillage, in the broadest sense of the word, all over Europe. Based on numerous scientific publications, obtained from the most eminent scientists in the field in Europe, a survey is given of the trends, scope and investigation results. In addition to some general considerations relating to soil tillage, conceptual interpretation is made of conservation soil tillage, estimation of soil suitability for its application, standing of conservation tillage in Europe and the development trends of minimum tillage, including treatments with chisel- and para-plough. Furthermore, conservation tillage is also treated from some other aspects, such as energy consumption, application of special seeding machines for the tillage system, weed control, erosion control, as well as changes of the physical, chemical and biological soil properties, with special emphasis on the relation between conservation tillage and nitrogen application, and partly plant diseases. At the end, a survey is given of the responses of some major field crops to different kinds of conservation tillage. On the assumption that this tillage system is further investigated, objectively and thoroughly, in terms of some of its specific characteristics in the ecological conditions of this country, it could find its permanent place in our agricultural production, not only as a substitute for the prevailing systems, in equivalent proportion, but also as a supplement to them

Conservation tillage in the European countries

Iz prikazanog rada vidljivo je da konzervacijska odnosno reducirana obrada tla u različitim europskim zemljama ima svoje specifičnosti. One ponajčešće proizlaze iz različitih ekoloških uvjeta, ali i objektivnih mogućnosti za prihvaćanje novih znanstvenih spoznaja i tehnoloških inovacija, a dijelom i različitih koncepcija u području obrade tla. Ipak, u većini zemalja konzervacijska obrada tla nije poprimila one razmjere koji bi se prema prirodnim uvjetima mogli očekivati. Ne treba smetnuti s uma i subjektivne poteškoće koje traže viši stupanj obrazovanja i veći smisao za znanstveni pristup konzervacijskoj obradi tla. Što se tiče naše zemlje, istraživanja s konzervacijskom obradom tla trebalo bi proširiti na sve tipove tala i one, prvenstveno ratarske kulture u kojih se očekuje pozitivna reakcija na konzervacijsku obradu tla.The presented paper points to the specific features of conservation, or reduced, tillage in different European countries. The specificities are mainly due to different ecological conditions, but also to objective potentials of adopting new scientific findings and technological innovations, and partly also different concepts in the sphere of soil tillage. Still, in most countries conservation tillage has not extended to such an extent as could be expected according to their natural conditions. Subjective difficulties demanding a higher educational level and orientation to the scientific approach to conservation tillage should not be disregarded either. As regards this country, investigations of conservation tillage should be extended to all soil types and to those, primarily field crops which are expected to respond favourably to conservation tillage

Regression Analysis of some Leaf Parameters of Burley Tobacco

Četiri roditeljska kultivara duhana tipa burley i šest njihovih F1 hibrida bila su uključena u četverogodišnja istraživanja načina nasljeđivanja pet parametara lista (dužine, širine, površine, debljine i težine lista), ovisno o njihovu položaju na stabljici, pomoću regresijske analize. Pokus je proveden prema metodi slučajnog bloknog rasporeda u četiri ponavljanja. Grafičkom metodom procijenjena je superdominacija u nasljeđivanju dužine, površine i debljine lista, neovisno o položaju lista na stabljici, kao i u nasljeđivanju širine 12. i 18. lista i težine 18. lista. Za većinu istraživanih svojstava nije prisutna interalelna interakcija testiranjem koeficijenta regresije, izuzev za dužinu 12. i 18. lista. Raspored točaka dijagrama rasapa duž očekivane linije regresije ukazuje na genetičku divergentnost roditelja. Za većinu istraživanih svojstava nositelj najvećeg broja dominantnih gena za 6. list bio je kultivar Poseydon, a za 12. i 18. list kultivar TN 86.Four parent burley tobacco cultivars and their six F1 hybrids were included in four-year trial, the aim of which was to investigate the manner of inheritance of five leaf parameters (lenght, width, area, thickness and weight), depending on their position on stalk, by means of regression analysis. The trial was set up according to the RCBD in four replications. Superdominance in inheritance of leaf length, area and thickness, independently of position on stalk, and in inheritance of width of 12th and 18th leaf and weight of 18th leaf was estimated by the graphic method. No interallelic interaction is present by testing regression coefficient for the most investigation traits, except for length of 12th and 18th leaf. Distribution of parent genotypes on the scatter diagram along the expected regression line points to genetic divergence of the parents. The highest number of dominant genes were found for most studied traits for 6th leaf for the cultivar Poseydon and for 12th and 18th leaf for the cultivar TN 86

CORRELATIONS AMONG ECONOMIC, MORPHOLOGICAL AND CHEMICAL TRAITS IN BURLEY TOBACCO

Cilj je ovih istraživanja bio procijeniti na odabranim genetskim materijalima duhana tipa burley korelacijske veze između gospodarskih (prinosa i grade indexa), morfoloških (visine zalamanja, visine biljke, dužine internodija, broja listova, početka cvatnje, dužine, širine, odnosa dužine i širine, površine, debljine i težine lista) i kemijskih svojstava (nikotina, bjelančevina, ukupnog dušika i pepela). Pokus je proveden prema metodi SBR u četiri ponavljanja na pokušalištu Duhanskog instituta Zagreb u Božjakovini u razdoblju od 1992. do 1995. godine. Za izračunavanje korelacija korišteni su četverogodišnji prosjeci između navedenih svojstava. Prema dobivenim rezultatima većinom su prisutne pozitivne korelacijske veze između istraživanih svojstava. Gospodarska i morfološka svojstva, izuzev početka cvatnje i odnosa dužine i širine lista, međusobno su u pozitivnoj, a većinom i u vrlo jakoj signifikantnoj korelacijskoj vezi. lzmeđu gospodarskih i morfoloških svojstava, s jedne strane, te kemijskih svojstava, s druge strane, većinom je prisutna negativna nesignifikantna korelacijska veza.The goal of these investigations was to estimate, on selected genetic materials, the correlations among economic (yield and grade index), morphological (topping height, plant height, internode length, leaf number, days to flowering, leaf length, leaf width, leaf L/W ratio, leaf area, leaf thickness and leaf weight) and chemical traits (nicotine, proteins, total nitrogen and ash). The trial was set up according to the RCBD in four replications at the experimental field of the Tobacco Institute Zagreb in Božjakovina from 1992 to 1995. Four-year average data among the mentioned traits were used for the calculation of correlations. According to the obtained results the investigated traits were mostly positively associated with each other. The economic and morphological traits, except days to flowering and L/W leaf ratio, were positively and mostly significantly correlated with each other. Mostly, strong to perfect correlations were estimated among these traits. Among economic and morphological traits, on the one hand, and chemical traits, on the other hand, correlations were mostly negative and nonsignificant

The influence of residual fertilizing by phosphorus and potassium upon sugar beat root yield and some soil chemical properties in crop rotation maize-soybean-winter wheat-sugar beat

Na lesiviranom tlu na pretaloženom lesu na lokalitetu Lukač (Virovitica) provedena su višegodišnja istraživanja gnojidbe na zalihu fosforom i kalijem za šećernu repu u sklopu četverogodišnjeg mjembenog plodoreda u dvije rotacije. Uz negnojenu varijantu i standardnu mineralnu gnojidbu, istraživanja su obuhvatila gnojidbu na zalihu u dvije varijante za četverogodišnje razdoblje i jednu varijantu za dvogodišnje razdoblje, dakako s različitim izvorima fosfora, pa donekle i kalija. Što se tiče prinosa korijena, šećerna je repa vrlo povoljno reagirala na gnojidbu na zalihu fosforom i kalijem, pri čemu ne bi trebalo biti dvojbe da je u tome kalij odigrao ključnu ulogu. Izvjesna, ali ipak samo relativna prednost na strani je tripleksa i kalijeve soli pred kompleksnim gnojivom. Povećanje sadržaja biljci pristupačnog fosfora i kalija u tlu prema višegodišnjim prosječnim vrijednostima nije sukladno primijenjenim količinama, iako je značajnije u kalija. Ipak, u pojedinim godinama to je povećanje signifikantno pod utjecajem fosforno-kalijeve gnojidbe. U relativnom se smislu smanjuje uglavnom zasićenost adsorpcijskog kompleksa bazama u odnosu na kontrolu. Vrijednosti u pojedinim godinama vrlo su heterogene pod utjecajem fosforno-kalijeve gnojidbe.Residual fertilization with phosphorus and potassium was investigated on sugar beet grown in two rotations within the four-year field crop rotation. The several years long trial was set up on luvic soil on redeposited loess at the locality Lukač (Virovitica). Besides the unfertilized variant and standard mineral fertilization, the trial also included two variants of residual fertilization for a four-year period and one variant for a two-year period, naturally with different sources of phosphorus, and partly also potassium. As regards its root yields, sugar beet responded favourably to residual fertilization with phosphorus and potassium, in which potassium indisputably played the key role. It was found that triplex and potassium salt had an advantage, though only relative, over complex fertilizer. According to average several-years values, increase of plant available phosphorus and potassium content in the soil was not proportional to their quantities applied, though it was more significant for potassium. Nonetheless, this increase was significant in some years due to phosphorus-potassium fertilization. In a relative sense, mainly the base saturation of the cation exchange capacity was reduced compared to the control. Under the influence of phosphorus-potassium fertilization, very heterogeneous values were recorded in particular trial years

SYSTEMS OF CONSERVATION TILLAGE AND CROPS

Istraživanje različitih oblika konzervacijske obrade tla uzelo je određenog maha za oranične usjeve. Najprije se navodi kraći pregled nekih radova koji tretiraju ovu problematiku općenito za te usjeve, a potom rezultati nekih istraživanja za pšenicu, ječam, kukuruz, šećernu repu i krumpir. Općenito se može reći da su postignuti pozitivni rezultati s uzgojem pšenice, ječma i kukuruza, slabiji sa šećernom repom, a s krumpirom tek je bilo nekih pokušaja, uglavnom u Norveškoj. Kod pšenice i ječma problem pri primjeni konzervacijske obrade predstavljale su sijačice za direktnu sjetvu. No, taj je problem manje više uspješno riješen. Glede kukuruza, istraživanja su još daleko iza sjevernoameričkih, ali s dužnom pažnjom da se i u Europi njima pristupi integralno. Pod utjecajem dugogodišnje empirije šećerna repa smatra se usjevom koji traži duboku obradu. Učinjeni su, međutim, napori da se i tom usjevu pristupi u duhu suvremenih uzgojnih metoda. Najmanje je pokušaja introdukcije različitih oblika konzervacijske obrade tla od navedenih mjera učinjeno s krumpirom. Ti pokušaji pokazuju ipak pozitivan ishod.Investigations into different forms of conservation tillage are in full swing for field crops. First, a short survey is given of some studies that treat these problems for field crops in general, and then the results of some investigations for wheat, barley, maize, sugar beet and potato are presented. A general conclusion is that positive results have been obtained in growing wheat, barley and maize, poorer results for sugar beet, while only some attempts have been made with potato, mainly in Norway. The problem in the application of conservation tillage for wheat and barley were direct drills. However, this problem was more or less successfully solved. Investigations involving maize still lag far behind those in North America, but due attention is paid to applying an integral approach to them also in Europe. Influenced by long-time experience, sugar beet is regarded as a crop demanding deep ploughing. Attempts, however, have been made to treat this crop as well in keeping with modern production methods. The fewest attempts at introducing different forms of conservation tillage have been made with potato, and their results are positive

DEVELOPMENTAL TRENDS IN MINIMUM SOIL TILLAGE, APPLICATION OF CHISEL PLOUGH AND PARAPLOUGH, AND CONSERVATION SOIL TILLAGE AND SOME OF PECULIARITIES

Ovaj rad bavi se razvojnim tendencijama u minimalnoj obradi tla, primjeni čizel pluga i "parapluga" u obradi tla, ulozi posebno konstruiranih sijačica u sustavu konzervacijske obrade tla, utroškom energije, postupcima sa slamom i suzbijanjem korova. Ukratko, minimalna obrada tla duboko se ukorijenila u praksu, što proistječe iz ekologije pojedinih regija, pa o njima ovisi i oblik minimalne obrade koja se primjenjuje. Obrada tla čizelom prihvaćena je ograničeno. To bi se moglo reći i za obradu "paraplugom". Širenje konzervacijske obrade tla ovisi o tehničkim inovacijama, pa će u tom pogledu značajno mjesto zauzeti novokonstruirane sijačice. Utrošak energije smanjuje se također primjenom konzervacijske obrade tla, iako je ovo pitanje još nedovoljno istraženo. Unošenje slame razmatra se s raznih aspekata, premda se ovaj problem svodi na dva učinka. Slama se može naći u ulozi malča ili činiti smetnje konzervacijskoj obradi tla. Pri suzbijanju pak korova pozornost treba posvetiti ekologiji i biologiji korova, te mehanizmima njihovog preživljavanja, odnosno interakciji između usjeva, korova, herbicida i obrade, uvažavajući činjenicu da se već i samom konzervacijskom obradom uništavaju korovi.The paper deals with the development trends in minimum soil tillage, application of chisel plough and paraplough in soil tillage, role of specially constructed drills in the conservation tillage system, energy consumption, straw involving procedures and weed control. Briefly, minimum soil tillage has become strongly established in the practice, depending on the ecology of different regions, which also determines the form of minimum tillage applied. Soil tillage with chisel plough has been accepted to a limited extent, which also holds for the paraplough. As spread of conservation tillage depends on technical innovations, newly constructed drills will have a significant role in this respect. Energy consumption is also reduced by conservation tillage, though this issue has been insufficiently studied to date. Introduction of straw is being considered from various aspects, though the problem is reduced to two effects. Straw may have the role of mulch or it can interfere with conservation tillage. In weed control, attention should be paid to weed ecology and biology, as well as to mechanisms of weed survival, that is, interactions between crops, weeds, herbicides and tillage, taking into account the fact that weeds are destroyed by conservation tillage itself

SYSTEMS OF CONSERVATION TILLAGE AND CROPS

Istraživanje različitih oblika konzervacijske obrade tla uzelo je određenog maha za oranične usjeve. Najprije se navodi kraći pregled nekih radova koji tretiraju ovu problematiku općenito za te usjeve, a potom rezultati nekih istraživanja za pšenicu, ječam, kukuruz, šećernu repu i krumpir. Općenito se može reći da su postignuti pozitivni rezultati s uzgojem pšenice, ječma i kukuruza, slabiji sa šećernom repom, a s krumpirom tek je bilo nekih pokušaja, uglavnom u Norveškoj. Kod pšenice i ječma problem pri primjeni konzervacijske obrade predstavljale su sijačice za direktnu sjetvu. No, taj je problem manje više uspješno riješen. Glede kukuruza, istraživanja su još daleko iza sjevernoameričkih, ali s dužnom pažnjom da se i u Europi njima pristupi integralno. Pod utjecajem dugogodišnje empirije šećerna repa smatra se usjevom koji traži duboku obradu. Učinjeni su, međutim, napori da se i tom usjevu pristupi u duhu suvremenih uzgojnih metoda. Najmanje je pokušaja introdukcije različitih oblika konzervacijske obrade tla od navedenih mjera učinjeno s krumpirom. Ti pokušaji pokazuju ipak pozitivan ishod.Investigations into different forms of conservation tillage are in full swing for field crops. First, a short survey is given of some studies that treat these problems for field crops in general, and then the results of some investigations for wheat, barley, maize, sugar beet and potato are presented. A general conclusion is that positive results have been obtained in growing wheat, barley and maize, poorer results for sugar beet, while only some attempts have been made with potato, mainly in Norway. The problem in the application of conservation tillage for wheat and barley were direct drills. However, this problem was more or less successfully solved. Investigations involving maize still lag far behind those in North America, but due attention is paid to applying an integral approach to them also in Europe. Influenced by long-time experience, sugar beet is regarded as a crop demanding deep ploughing. Attempts, however, have been made to treat this crop as well in keeping with modern production methods. The fewest attempts at introducing different forms of conservation tillage have been made with potato, and their results are positive

DEVELOPMENTAL TRENDS IN MINIMUM SOIL TILLAGE, APPLICATION OF CHISEL PLOUGH AND PARAPLOUGH, AND CONSERVATION SOIL TILLAGE AND SOME OF PECULIARITIES

Ovaj rad bavi se razvojnim tendencijama u minimalnoj obradi tla, primjeni čizel pluga i "parapluga" u obradi tla, ulozi posebno konstruiranih sijačica u sustavu konzervacijske obrade tla, utroškom energije, postupcima sa slamom i suzbijanjem korova. Ukratko, minimalna obrada tla duboko se ukorijenila u praksu, što proistječe iz ekologije pojedinih regija, pa o njima ovisi i oblik minimalne obrade koja se primjenjuje. Obrada tla čizelom prihvaćena je ograničeno. To bi se moglo reći i za obradu "paraplugom". Širenje konzervacijske obrade tla ovisi o tehničkim inovacijama, pa će u tom pogledu značajno mjesto zauzeti novokonstruirane sijačice. Utrošak energije smanjuje se također primjenom konzervacijske obrade tla, iako je ovo pitanje još nedovoljno istraženo. Unošenje slame razmatra se s raznih aspekata, premda se ovaj problem svodi na dva učinka. Slama se može naći u ulozi malča ili činiti smetnje konzervacijskoj obradi tla. Pri suzbijanju pak korova pozornost treba posvetiti ekologiji i biologiji korova, te mehanizmima njihovog preživljavanja, odnosno interakciji između usjeva, korova, herbicida i obrade, uvažavajući činjenicu da se već i samom konzervacijskom obradom uništavaju korovi.The paper deals with the development trends in minimum soil tillage, application of chisel plough and paraplough in soil tillage, role of specially constructed drills in the conservation tillage system, energy consumption, straw involving procedures and weed control. Briefly, minimum soil tillage has become strongly established in the practice, depending on the ecology of different regions, which also determines the form of minimum tillage applied. Soil tillage with chisel plough has been accepted to a limited extent, which also holds for the paraplough. As spread of conservation tillage depends on technical innovations, newly constructed drills will have a significant role in this respect. Energy consumption is also reduced by conservation tillage, though this issue has been insufficiently studied to date. Introduction of straw is being considered from various aspects, though the problem is reduced to two effects. Straw may have the role of mulch or it can interfere with conservation tillage. In weed control, attention should be paid to weed ecology and biology, as well as to mechanisms of weed survival, that is, interactions between crops, weeds, herbicides and tillage, taking into account the fact that weeds are destroyed by conservation tillage itself

THE INFLUENCE OF THE SYSTEM OF CONSERVATION TILLAGE UPON THE CHEMICAL PROPERTIES, NITROGEN APPLICATION, BIOLOGICAL PROPERTIES AND PLANT DISEASES

Rad se bavi utjecajem konzervacijske obrade tla na kemijska svojstva, primjenu dušika, biološka svojstva i biljne bolesti. Kada je riječ o kemijskim svojstvima tla, treba reći da su ona u prvom redu pod utjecajem gnojidbe. Naravno, ovise i o obradi, čiji je utjecaj na raspored hraniva u obrađenom sloju dominantan. To se prvenstveno odnosi na fosfor i kalij, dok je ponašanje dušika specifično s obzirom na njegovu specifičnu dinamiku u tlu. Biološka aktivnost također je povezana s konzervacijskom obradom tla, posebno što se tiče gujavica. Također utječe i na mikrobiološku sliku tla. Pod utjecajem konzervacijske obrade tla mijenja se i broj mikroorganizama, osobito ako ne dolazi do okretanja tla. Gomilanjem pak većih količina biljnih rezidua pri različitim oblicima konzervacijske obrade tla stvaraju se povoljni uvjeti za širenje biljnih bolesti. Integralna zaštita bilja protiv štetočina u velikoj se mjeri oslanja na rezistentne sorte, ali isto tako na kemijske i biološke metode.The paper deals with the influence of conservation tillage upon chemical properties, nitrogen application, biological properties and plant diseases. As regards soil chemical properties, it should be stressed that they are mainly influenced by fertilization. They naturally depend on soil tillage, which has a dominant effect on the distribution of nutrients in the tilled layer. This primarily applies to phosphorus and potassium whereas nitrogen behaves in a specific way due to its specific dynamics in soil. Biological activity is also associated with conservation tillage, notably with regard to earthworms. It also affects the microbiological state of soil. The number of microorganisms changes under the influence of conservation tillage, especially if soil is not turned over. Accumulation of large amounts of plant residues in different forms of conservation tillage creates conditions favouring spread of plant diseases. Integral plant protection against pests greatly relies on resistant cultivars, but also on chemical and biological methods