Carbon and nitrogen uptake in above- and below-ground biomass of cereal crops in the integrated farming system

S. Rancane¹²*, A. Lazdins², A. Zusevica², S. Zute³, I. Jansone³, M. Damskalne³, L. Zarina³, J. Korolova⁴ and O. Maliarenko⁵

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
*Correspondence: sarmite.rancane@llu.lv

Abstract:

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.

Key words:

cereal crops, crop residues, harvest index, shoot/root ratio

Incidence of Fusarium spp. on several field crops in Estonia and their toxicity towards Bacillus stearothermophilus

H. Lõiveke

Estonian Research Institute of Agriculture, Teaduse 13, EE75501 Saku, Harjumaa, Estonia;e-mail: heino.loiveke@eria.ee

Abstract:

The article provides an overview of the occurrence of Fusarium spp. on grain produced in Estonia from 1973–2004, the occurrence of Fusarium spp. in the common root rot complex of cereals in 1977–1985 and potato tubers with dry rot symptoms in the yield of 1996–2000. The dominating species on grain were (contaminated samples, %) F. avenaceum (Fr.) Sacc. – 28.0–30.3; F. poae (Pk.) Wr. – 7.4–9.5 F. semitectum Berk. et Rav. – 7.0–9.0; F. oxysporum (Schlecht) Snyd. et Hans. – 7.4-8.0; accompanied by F. ventricosum App. et Wr., F. sporotrichioides Sherb. var. minus Wr., F. verticillioides (Sacc.) Nirenberg, F. culmorum (W. G. Sm.) Sacc. and F. sambucinum Fuck. In the common root rot complex of barley, F. culmorum – 16.8; F. sambucinum – 2.5; F. avenaceum – 2.2; F. oxysporum – 1.7; and F. poae – 1.3 (contaminated samples, %) dominated. In potato with dry rot, F. culmorum – 26.7; F. solani (Mart.) Sacc. – 20.0; F. poae – 15.0; F. oxysporum – 13.3 and F. sulphureum Schlecht – 8.3 (contaminated tubers, %) dominated. The occurrence of toxic isolates both on grain and potato was established. Of Fusarium isolates recovered from grain (total 287) 5.6% were highly toxic, and 88.1% mildly or medium toxic to Bacillus stearothermophilus. Of 15 isolates found on potato, 1 was highly toxic and 9 were mildly to medium toxic. Fusarium spp. has been presented according to Gerlach & Nirenberg (1982).

Key words: