Yield and quality of winter wheat (Triticum aestivum L.) growing in ecological and low-input farming systems

The aim of the study is to compare yield height and quality of winter wheat in two different farming systems (ecological and low-input) and at two levels of nitrogen fertilization (N1, N2 - 40 or 80 kg N/ha). In the years 1999-2001 the stationary field experiment was established on degraded Chernozem on loess (Luvi-haplic Chernozem) in a maize-barley growing region in south-western Slovakia (near the town Piestany) with good content of available potassium, normal content of available phosphorus and high content of available magnesium, with the humus content 1.8 - 2.0 %. The areas has a continental climate with the average annual temperature 9.2 deg C and mean annual precipitation 593 mm. The experimental plots are situated in the protected zone of water resources. The experimental field crop was spring barley (Hordeum vulgare L.) which was integrated into six-field crop rotation: meadow lover (variety Margot), winter wheat (variety Torysa) + intercrop, field pea (variety Olivin), winter wheat (variety Astella), potato (variety Eta) fertilizing with farm-yard manure + intercrop, spring barley (variety Atribut) with underseeding meadow clover (variety Margot). Farming systems: ES - ecological system (all cultural practices were realized in accordance with the law NR SR No. 224/ 1998 about ecological agriculture and biofoodstuff production), LIS - integrated system (system when industrial fertilizers, pesticides and conventional soil cultivation were used, straw and crop residues were ploughed in the soil and consumed nutrients were supplemented by industrial fertilizers). Variants of nitrogen fertilization: N1 - rate of nitrogen fertilizer presented 50 % of permissible nitrogen dose in the protected zone of water resources (40 kg N/ha), the rate was divided into 20+20 kg N/ha. N2 - rate of nitrogen fertilizer presented maximum of permissible nitrogen dose in the protected zone of water resources (80 kg N/ha), the rate was divided into 30+30+20 kg N/ha. In ecological system winter wheat was dressed by commercial compost (commercial name Vitahum, producer EBA Bratislava, Slovakia), in low input system winter wheat was dressed by nitre form of nitrogen. The rates of phosphorus and potassium were determined on the planned grain yield 7 tons of winter wheat, 6 tons of spring barley, 4 tons of field pea, 20 tons of potatoes and 10 tons of clover per hectare. Besides the yield height we observed protein content, wet gluten content, and levels of sedimentation test defined on the NIR Systems 6500, grain hardness and proportion of grain over the sieve 2.5 mm. Obtained results were evaluated by variance analysis. The results show that yield height and practically all studied parameters were strongly affected by the year. The higher grain yield of winter wheat at average of three years was in low input farming system, but the difference was not statistically significant in comparison with ecological system. Significantly higher values of proteins, wet gluten content and grain hardness contained the winter wheat in low input farming system. The nitrogen dosages, determined on the basis of regulations valid in the protective zone of underground water resources, influenced the protein content, wet gluten content, grain hardness, and significant on the values of sedimentation test. From the results follow that in term of grain yield height, both farming systems are equivalent in efficiency, but in term of evaluation of the qualitative characteristic in this soil-ecological conditions and very different climatic conditions, more favorable quality values were recorded at the winter wheat growing in low input farming system.