engleski

Rational soil tillage for cereals (Winter wheat - Triticum aestivum and Spring Barley - Hordeum vulgare L.) in eastern Croatia

Production of cereals in eastern part of the Republic of Croatia is based on conventional soil tillage comprising of ploughing (20-25 cm) and standard seedbed preparation (diskharrowing, harrowing, seeding). Energetically, economically and organisationally, it is the most expensive tillage, although the most yielding technology. The latest years however, the investigations and the practice in Eastern Croatia show the possibility of reducing the cost of basic soil tillage with acceptable level of cereal yields, depending on soil types, pre-crops, weather conditions and cereal crop species. The scope of this work is to give some new information relating to possibilities of this new technology for winter wheat and two- rowed spring barley in the eastern part of the country. Three basic crops have been investigated in crop rotation – winter wheat or spring barley and maize in stationary investigation, on lessive-pseudogley soil type, on the arable land of “Čačinci” unit (PP “Orahovica” enterprise), during of three years: 1996/97 and 1997/98 – winter wheat, and 1999 spring barley, with the following five soil tillage treatments: 1 – Standard, conventional soil tillage based on ploughing (25-30 cm) and diskharrowing, then classical sowing ; 2A – standard ploughing and diskharrowing, like at variant 1 in one, then only diskharrowing (10- 15 cm) in the second year, and alternately in the following years ; 2B – only diskharrowing (10-15 cm) in one, and standard ploughing and diskharrowing like at var. 1 in the second year, and alternately in the following years (2A and 2B are alternatives) ; 3 – only diskharrowing (10-15 cm) continuously ; and 4 – tillage based on diskharrowing and seed-bed preparation, like at var. 3, but combined by loosening or chisel ploughing of plowlayer only (up to 30 cm) by Shakearator (McConnel, 40 cm spacing between subsoiling chisels) in 1996/97 and 1997/98, or by Pseudo (chisel) plough (pitch 15-21 cm, working depth up to 40 cm) in 1998/99. Fertilisation for the whole experimental field was based on 231 kg N for winter wheat and 120 kg N for spring barley, 150 kg P2O5 and 100 kg K2O/ha. The basic plot area was 720 m2 (18x40 m), the trial was as monofactorial, carried out as randomised plots in blocks, in four replications. Variety “Demetra” (w. wheat) and “Jaran” (s. barley), as creations of the Agricultural Institute Osijek, were sowed on 13th November 1997 and 4th November 1998 (relatively late for w. wheat in Croatia) and 12. March 1999 (s. barley). Plant protection against weeds, diseases (Erisiphe graminis) and pests (Lema melanopus) has been uniformed, and carried out by standard pesticides. Regarding to weather conditions, the vegetation periods were completely different, consequently the yields were rather heterogeneous. The first year (1996/97) was registered as pretty unfavourable for winter wheat production (extremely wet), with consequence of very low grain yields in large farm production as well as in the trial. Therefore the conclusions were not reliable enough. The following grain yields were registered: on variant 1 (standard) the yield was 4.13 ; var. 2A=4.00 ; var. 2B=3.53 ; var. 3=3.36, and var. 4=4.04 t/ha, all without significant differences (LSD P0.05=0.90 ; P0.01=1.25 t/ha). The second year (1997/98) was very favourable and the obtained grain yields were relatively high: var. 1=6.26 ; var. 2A=6.21 ; var. 2B=6.06 ; var. 3=6.00, and var. 4=6.36 t/ha, again without statistically significant differences (LSD P0.05=0.45 ; P0.01=0.63 t/ha). The third year, with spring barley, was again with unfavourable weather conditions for cereals, especially for spring barley, and the yields were commonly low. Variant 1 (standard) gave 3.43 ; var. 2A=3.32 ; var. 2B=3.38 ; var. 3=3.07, and var. 4=3.30 t/ha. Differences among treatments were all statistically non-significant (LSD P0.05=0.77). Regarding to cereals tillage technology conclusions could be that in spite of that the yields obtained by conventional soil tillage were within the highest yields, the other alternative tillage practices were successful, too. Also, diskharrowing combined with loosening of the main root zone of plowlayer deserve a special attention as a sustainable substitute for ploughing.

reduced tillage ; winter wheat ; spring barley ; standard conventional tillage ; diskharrowing ; diskharrowing and chisel ploughing ; ploughing in alternation with diskharrowing

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