Minerālā slāpekļa dinamika augsnē 2015.–2016. gada izmēģinājumos
2017
Karklins, A., Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Agriculture | Lipenite, I., Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Agriculture | Ruza, A., Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Agriculture
Mineral (N–NO3+N–NH4) nitrogen content in soil was monitored during crop vegetation of 2015 and 2016. Research polygons were located in six geographical places of Latvia and consisted of 24 trial plots covering the diversity of soil conditions, crops and nitrogen fertiliser applications. The aim of the study was to investigate the distribution of mineral nitrogen (Nmin.) content within the soil profile (0–30; 30–60 and 60–90 cm depth) monthly, starting from early spring up to late autumn. The crops grown included winter and spring wheat, winter rape, spring barley, potatoes, faba bean, maize and vetch-oat mixture for green forage. Different pattern of nitrogen applications was realized starting from 0 up to 240 kg haE-1 N. The content of mineral nitrogen in soil was variable depending on weather conditions, crop grown, soil and fertiliser applications. During vegetation period at the time of soil tillage and fertiliser application increase of Nmin. content in soil was observed, especially in the topsoil layer. During summer time Nmin. content decreased gradually due to its consumption by crops. The main amount of Nmin. was placed in the layer at 0 – 30 cm depth in the form of nitrates. In most cases after harvesting of crops Nmin, content in soil increased again causing some environmental risks as a result of potential leaching losses.
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