Carbon and nitrogen uptake in above- and below-ground biomass of cereal crops in the integrated farming system
¹Research Institute of Agronomy of Latvia University of Life Sciences and Technologies, J. Purapukes street 28, LV-5125 Skriveri, Latvia
²Latvia State Forest Research Institute Silava, Rigas street 111, LV-2169 Salaspils, Latvia
³Institute of Agricultural Resources and Economics, Struktoru street 14, LV-1039 Riga, Latvia
⁴Latvia University of Life Sciences and Technologies, Liela street 2, LV-3001 Jelgava, Latvia
⁵Institute of Bioenergy Crops and Sugar Beet, 25 Klinichna street, UA03110 Kyiv, Ukraine
A significant reduction in greenhouse gas (GHG) emissions, as well as technologies that ensure removal of CO2 from the atmosphere, are necessary to achieve the set goals for the transition to carbon neutrality. During the crop growth cycle, a significant amount of biomass is produced, and carbon (C) and nitrogen (N) are captured both by the harvested crop removed from the field and by residues left on the field. The trials were conducted to find out patterns between crop and residues while trying to figure out the amount of captured C and N. In this study data of the most widely grown cereal crops in Latvia are summarized. The data are representative, obtained in different agroclimatic conditions, they vary both by species and variety, by year and fertilizers applied. The mean amount of biomass from cereal crops left on the field was 1,070.9 g m-2 DM, besides, 906.7 g m-2 of that was made up of above-ground (AG) residues and 164.2 g m-2 of below-ground (BG) residues. On average, 471.8 g m-2 C and 14.3 g m-2 N were captured, including: 411.2 g m-2 C and 12.9 g m-2 N by AG residues; 60.7 g m-2 C and 1.4 g m-2 N by BG residues. Regularities between grain yield and residues were found, however, they were not very strong. The dataset should be enlarged to reduce uncertainty. As the data calculated from crop have a greater uncertainty, the GHG inventory should be calculated according to the average AG and BG biomass, which provide more accurate data.