The use of legumes as a biogas substrate - potentials for saving energy and reducing greenhouse gas emissions through symbiotic nitrogen fixation

Table 3 Savings of energy and greenhouse gases by replacing mineral nitrogen

Element of cultivation	SNF	Replacement of mineral fertilizer	Savings of energy [kWh ha ⁻¹ ]	Savings of greenhouse gases [kg CO ₂ eq. ha ⁻¹ ]
Clover grass leys as catch crop (CC, autumn growth after harvest of spring wheat)	65	52	841	275
Clover grass leys (year of main crop)	498	398	6,436	2,101
CC after WW3	77	62	1,003	327
CC after peas	36	29	469	153
CC after WW5	66	53	857	280
$$ \overline{\mathbf{x}} $$ CC	61	49	792	259
Σ arable land (AL, 6 ha)	730	584	9,443	3,084
$$ \overline{\mathbf{x}} $$ AL	122	98	1,578	517

Acronyms: WW3 = winter wheat in third place of crop rotation, WW5 = winter wheat in fifth place of crop rotation.