Poljoprivreda (Dec 2012)
INFLUENCE OF REDUCED SOIL TILLAGE AND NITROGEN FERTILIZATION AT WINTER WHEAT AND SOYBEAN GRAIN YIELDS AT BARANYA HIPOGLEY SOIL TYPE
Abstract
During the three years (2006/2007-2008/2009) stationary research of reduced soil tillage had been conducted for winter wheat and soybean, at marsh gley (hipogley) hydromeliorated soil type of Baranya. The research has been conducted with eight soil tillage treatments and three nitrogen fertilization treatments set up in split-plot design in four repetitions. Soil tillage treatments consisted of four continued soil tillage systems for both crops: OR-conventional soil tillage, TR-multiple diskharrowing, RT-chiseling and diskharrowing, NT-no-tillage and four discontinued soil tillage systems: OsTp-OR for soybean TR for w. wheat in the forthcoming season: OpTs-OR for w.wheat TR for soybean in the forthcoming season, NpOs-NT for w. wheat OR for soybean in forthcoming season: NsOp-NT for soybean OR for w. wheat in forthcoming season. Nitrogen fertilization treatment had three levels of applied nitrogen: for w.wheat G-1=120, G-2=150, G-3=180 kg N ha -1 and for soybean G-1=35, G-2=70, G-3=110 kg N ha-1. Weather conditions had significant aberrations during 2006/2007 and 2008/2009 (extremely drought seasons), whereas 2007/2008 season was moderately humid. The high and stabile average winter wheat grain yields had been achieved, with statistical difference among years of the research, whereas yield decreased by applied soil tillage systems in the order as follows: RT (7.78) > NsOp (7.75) > OR (7.74) > OpTs (7.62) > TR (7.63) > OsTp (7.58) > NpOs (6.95) > NT (6.92 t ha-1), with NpOs and NT treatments recorded significantly lower yields in comparison with OR treatment. According to three year averages, normal and relatively stabile soybean grain yield has been achieved, with significant difference among years, whereas soil tillage systems showed the following decrease order: NpOs (2.62) > OR (2.58) > OsTp (2.56) > NsOp (2.49) > TR (2.46) = RT (2.46) > NT (2.42) > OpTs (2.35 t ha-1). In comparison with OR treatment, only OpTs had significantly lower soybean grain yield. The study showed, with the optimum of nitrogen fertilization, a very successful application of reduced soil tillage systems in the winter wheat and soybean production.
