*2.2. Field Trial Description*

The design and methodology of all three trials (in three localities) are equal. The trial consists of four fields, where twelve fertilizer treatments are applied and analysed (twelve treatments per one field) in randomized complete block design. Each fertilizer treatment is replicated four times (12 × 4 = 48 experimental plots per one field). The size of one experimental plot is 64 m<sup>2</sup> (8 × 8 m).

Out of twelve fertilizer treatments, seven treatments are evaluated in this paper: (1) the unfertilized control (control); (2) farmyard manure (FYM); (3–4) farmyard manure applied with mineral nitrogen (FYM+N1; FYM+N2); and (5–7) farmyard manure applied with mineral nitrogen, phosphorus, and potassium (FYM+N1PK; FYM+N2PK; FYM+N3PK). The doses of applied farmyard manure and mineral fertilizers are shown in Table 3. Mineral nitrogen was applied as lime ammonium nitrate, the mineral phosphorus as granulated superphosphate, and potassium as potassium chloride. The FYM and mineral fertilizers were spread by hand. Applied FYM (cattle farmyard manure from local farmers) was incorporated into the soil within 24 h after application. The FYM was in the crop rotation applied to the maize, three years before the wheat was sown (2012—maize, 2013—spring barley, 2014—winter rapeseed, 2015—winter wheat), so winter wheat was the fourth crop following the FYM application. If the FYM and mineral fertilizers were applied together, mineral fertilizers were applied first (the case of maize in the crop rotation, no FYM was applied to spring barley, winter rapeseed, and winter wheat). The dose of FYM, applied to the maize, was 40 t ha−<sup>1</sup> (approximately 200 kg N ha−1, 56 kg P ha−1, and 236 kg K ha−1). Because winter wheat was sown three years after the FYM was applied, we estimate that the total amount of available nutrients from FYM to wheat was 5% (10 kg N ha−1, 3 kg P ha−1, and 12 kg K ha−1) (for further information, see Section 4.4.).


**Table 3.** Doses of N, P, and K (kg ha−1) applied in selected fertilizer treatments. FYM, farmyard manure; N, mineral nitrogen; P, phosphorus; K, potassium.

> Note: values in parentheses represent the amount of nutrients mineralised from manure.

Mineral nitrogen was applied in the autumn before the wheat was sown (40 kg N ha−1, N1, N2, and N3 treatments), during the beginning of the spring for regeneration (40 kg N ha−1, N2 and N3 treatments, late February, beginning of March), and during the May to support the grain production (40 kg N ha−1, N3 treatment). The P and K fertilizers were applied during the autumn, before the wheat was sown.

Winter wheat cultivar, sown between 2014/2015 and 2017/2018, was Julie (Selgen a.s., Sibˇrina, the Czech Republic). It is a short straw cultivar offering high yields in all cropping areas, high frost resistance, offering class "E" (elite) grain quality, and a high volume of bakery products. Wheat was sown in October (according to the climate conditions), the depth of sowing ranged from three to four cm, the row spacing was 12.5 cm, and the sowing rate was 400 seeds per m2. Pesticides were used during the experiments if necessary, while growth regulators havenot been introduced and applied. The harvest was done during the right BBCH stage, and was performed by the HEGE 180 (Hege Maschinen GmbH, Lichtenstein, Germany) in Ivanovice, Sampo Rosenlew 2010 (Sampo Rosenlew Ltd., Pori, Finland) in Caslav, and by Seedmaster Universal, Wintersteiger (Ried im Innkreis, Austria) in Lukavec.
