Efluents from biogas production may be recycled to soil as plant nutrition. However, the proportion of plant-available nitrogen is high and may cause loss due to leaching or gaseous emissions. Hence, such waste stream materials must be applied with care to ensure maximum plant uptake to minimize loss. Spread of weed seeds via application of biogas effluents is only a problem when the digestion is performed at mesophilic conditions and when the seeds are staying less than a week in the plant. At thermophilic conditions, seeds from a range of weed plant were unable to germinate efter just a few days
