Carbon and nitrogen accumulation by agricultural crop residue under three cropping systems

S. Rancāne¹*, A. Lazdiņš², G. Petaja², D. Purviņa², S. Zute³, I. Jansone³, M. Damškalne³ and G. Putniece⁴

¹Latvia University of Life Sciences and Technologies, Research Institute of Agronomy, 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, Stende Research Centre, LV-3200 Dizstende, Talsi district, Latvia
⁴Latvia University of Life Sciences and Technologies, Liela street 2, LV-3001 Jelgava, Latvia
*Correspondence: sarmite.rancane@lbtu.lv

Abstract:

Agricultural crops produce different biomass during their growth, including varying amounts of residue which accumulate a significant amount of carbon (C) and nitrogen (N). Assimilation capacity depends largely on species, variety and growing condition. Carbon accumulation in soil contributes to both – the agricultural production and maintenance of environmental quality reducing atmospheric C and greenhouse gas emissions. In this study, the amount of plant residue left on the field by above-ground and below-ground residue and the amount of C and N accumulated in them in three different cropping systems: organic (Bio); integrated with a low input of N fertiliser (Int-low-N) and; integrated with a high input of N fertiliser (Int-high-N) were evaluated. The most commonly grown cereal crops in Latvia were tested: winter wheat (WW); summer wheat (SW); winter rye (WR); winter triticale (WT); summer barley (SB); summer oat (SO); and buckwheat (BW) as pseudo-cereal crop. The highest biomass of dry matter of total harvest residue in all cropping systems was recorded in WR: 853.3 ± 40.76 g m^-2; 1,482.0 ± 105.06 g m^-2; 1,628.3 ± 115.49 g m^-2 – in Bio; Int-low-N; Int-high-N cropping systems, respectively. The highest amount of carbon (g C m^-2) using organic cropping system was accumulated by residue of: WR (268.6 ± 28.68), BW (239.4 ± 10.50) and WW (234.5 ± 27.41). The highest amount of carbon (g C m^-2) using integrated cropping system was accumulated by residue of: WR – 473.8 ± 64.9; 496.6 ± 62.54 and WT – 458.2 ± 32.57; 521.1 ± 46.26 in Int-low-N and Int-high-N, respectively. Higher proportion of root biomass cereals formed using organic cropping system.

Key words:

: above-ground and below-ground residue, cereal crops, integrated cropping system, organic cropping system