Influence of Different Tillage Systems on Yield of Maize on Stagnic Luvisols of Central Croatia

Polazeći od potrebe da se utvrdi optimalna dubina obrade, odnosno da se obrada učini jednostavnijom i jeftinijom, uz puno respektiranje edafskih i klimatskih uvjeta, te bioloških i agrotehničkih potreba uzgajanih usjeva, provode se višegodišnja istraživanja optimalne dubine osnovne obrade na obronačnom pseudogleju središnje Hrvatske. U ovom radu prikazujemo rezultate vezane uz prinos zrna kukuruza. Tijekom 1995. godine najviši prinos od 9,60 t/ha je ostvaren na oranju uz odnosno niz nagib. U godinama s nedostatkom oborina do izražaja dolaze varijante s dubljom obradom, pa je tako u drugoj godini istraživanja (2000. g.) najviši prinos od 7,97 t/ha ostvaren na varijanti s vrlo dubokim oranjem. U obje godine istraživanja signifikantno niži prinos je ostvaren na varijanti s izostavljanjem obrade. Temeljem ostvarenih prinosa može se zaključiti da izostavljanje obrade na pseudogleju ne može imati ravnopravan položaj s klasičnom, standardnom obradom tla. No, uzimajući u obzir ostvarene niže prinose s jednu stranu, ali i uštedu u energiji na izostavljanju obrade s druge strane, ovaj sustav traži da mu se posveti još više pažnje u budućim istraživanjima. S obzirom na aktualnost primjene bilo kog od reduciranih načina obrade tla u nas, a imajući u vidu složenost ove problematike, tj. primjenu novih sustava obrade tla, potreban je daljnji temeljiti, dugogodišnji i kompleksni istraživački multidisciplinarni rad u koji bi bili uključeni znanstvenici koji mogu rasvijetliti ovu problematiku.Aimed at determining the optimal ploughing depth and making tillage simpler and less costly, taking into account edaphic and climatic conditions as well as biological and agrotechnical requirements of crops grown, longterm investigations of the optimal depth of basic tillage are carried out on Stagnic Luvisols of sloping terrains in central Croatia. This paper presents the results relating to the yields of maize grain. Yields achieved by the studied tillage treatments point to the conclusion that the no-tillage variant on the soil type under study (Stagnic Luvisols) cannot match the classical, standard soil tillage. Conventional tillage to different depths in any direction is still a safe warranty for high yields on this soil type. In the first trial year, the highest yield of 9.60 t ha-1 was obtained with ploughing up/down the slope. In precipitation deficient years, treatments with deeper ploughing are more efficient. Thus, in the second trial year, the highest yield of 7.97 t ha-1 was achieved in the variant involving very deep ploughing. With respect to the topical trend of applying any of the reduced tillage treatments in our agriculture, and considering the complexity of this problem, namely, application of a new soil tillage technology, further detailed, longterm and complex multidisciplinary research work is necessary, which should include researchers from all fields relating to these problems