Effect of different farming systems and nitrogen fertilization on the yield, selected yield traits and some qualitative characters of spring barley

The aim of the experiment was to determine the effect of different farming systems (integrated and low-input) and two levels of nitrogen fertilization on yield height, selected yield formation traits and on some qualitative characters of spring barley variety Atribut. In the 1999-2001 years the stationary field experiment was established on degraded Chernozem on loess (Luvihaplic Chernozem) in maize-barley growing region in south-western part of the Slovak Republic (near Piestany city) with good content of available potassium, medium content of phosphorus and high content of magnesium, with the humus content 1.8 - 2.0 %. The areas have a continental climate with the average annual temperature 9.2 deg C and mean annual precipitation 593 mm. The experimental field crop was spring barley (Hordeum vulgare L.) which was integrated into four - field crop rotation: pea (variety Olivin) - winter wheat (variety Astella) plus intercrop - grain maize (variety Stira) plus compost (30 t/ha) - spring barley (variety Atribut) plus intercrop. Farming systems: LIS - low-input system (system with classical tillage and with application of pesticides and industrial fertilizers, straw and crop residues were delocalized from the field and consumed nutrients were supplemented only by industrial fertilizers, chemical plant protection and weed control with herbicides). IS - integrated system (system without livestock production, preferential utilization of self-regulated mechanisms: crop rotation with intercrops, selection of tolerant varieties, no-tillage technologies, integrated fertilization and nutrition). Treatments of nitrogen fertilization (experimental plots are situated in the protected zone of water resources): N1 - mineral fertilization in dose 30 kg N/ha was applied. N2 - mineral fertilization in maximum of permissible nitrogen dose in the protected zone of water resources (50 kg N/ha) was applied. The rate of phosphorus and potassium was determined on the planned grain yield: for winter wheat 7 t/ha, for spring barley 6 t/ha, for pea 4 t/ha and for grain maize 8 t/ha. Besides the yield, the selected yield traits (number of plants per square meter, one- thousand grain weight, grain weight in a spike, length of a spike, proportion of grain over sieve 2.5 mm) and some qualitative characters (grain volume weight and extract content) were observed. Obtained results were evaluated by variance analysis. The results showed that practically all studied parameters were strongly affected by a year. The significantly higher grain yield of spring barley in low-input farming system (4.70 t/ha) in comparison the grain yield in integrated system (3.73 t/ha) was reached. In term of reached qualitative parameters spring barley from integrated system was considered the more qualitative. Any studied parameters with the exception of proportion of grain over sieve 2.5 mm and extract content were not influenced the different rates of nitrogen fertilization. Statistically lower proportion of grain over sieve 2.5 mm at higher rate of nitrogen fertilization was reached. Statistically significantly higher extract content at N1 (lower rate of nitrogen fertilization) was found out.