Effects of biogas and raw slurries on grass growth and soil microbial indices.

Biogas slurry is increasingly used as fertilizer. Earlier research was focused on plant growth and soil chemical properties, with only little information available regarding the effects of biogas slurry on soil and root microbial indices. For this reason, a 70 d pot experiment was conducted in which biogas and raw slurries obtained from six biodynamic farms were added to a soil. Italian ryegrass (Lolium multiflorum Lam.) was cultivated to investigate the effects on plant yield, N uptake (two harvests), soil microbial biomass, soil fungi, and root-colonizing microorganisms. Biogas slurries increased the mean total above-ground plant biomass by 66% and raw slurries by 35% in comparison to the control. The mean plant N-uptake increased under biogas and raw slurry application by 166% and 65%, respectively, compared with the unfertilized pots. The effects of biogas and raw slurry application on soil microbial indices were similar except for the lower fungal biomass after biogas slurry amendment. In contrast to biogas slurries, the raw slurries significantly increased microbial biomass C and N by roughly 25% in comparison to the control. The application of biogas slurries significantly decreased the soil ergosterol content in comparison with raw slurry and control treatment, leading to a significantly lower ergosterol : microbial biomass C ratio. In the roots, biogas and raw slurry application significantly decreased the concentrations of the amino sugars galactosamine and glucosamine by 39 and 27%, respectively, but not that of ergosterol in comparison with the control. This was most likely due to a reduced colonization with arbuscular mycorrhizal fungi in the presence of highly available plant nutrients.

[1]  Monica Odlare,et al.  The fertilizing effect of compost and biogas residues from source separated household waste , 2004, The Journal of Agricultural Science.

[2]  B. Eichler-Löbermann,et al.  Codigested dairy slurry as a phosphorus and nitrogen source for Zea mays L. and Amaranthus cruentus L. , 2011 .

[3]  D. Douds,et al.  Phosphorus amendment inhibits hyphal branching of the VAM fungus Gigaspora margarita directly and indirectly through its effect on root exudation , 1996, Mycorrhiza.

[4]  Lingli Liu,et al.  A global perspective on belowground carbon dynamics under nitrogen enrichment. , 2010, Ecology letters.

[5]  B. Ma,et al.  Acquisition of Cu, Zn, Mn and Fe by mycorrhizal maize (Zea mays L.) grown in soil at different P and micronutrient levels , 2000, Mycorrhiza.

[6]  R. Joergensen,et al.  Changes in soil-biological quality indices after long-term addition of shredded shrubs and biogenic waste compost , 2006 .

[7]  R. Joergensen,et al.  The automated determination of glucosamine, galactosamine, muramic acid, and mannosamine in soil and root hydrolysates by HPLC , 2004 .

[8]  B. Frey,et al.  Chitin and ergosterol content of extraradical and intraradical mycelium of the vesicular-arbuscular mycorrhizal fungus Glomus intraradices , 1994 .

[9]  A. P. Williams,et al.  Fungal and bacterial growth following the application of slurry and anaerobic digestate of livestock manure to temperate pasture soils , 2012, Biology and Fertility of Soils.

[10]  M Odlare,et al.  Changes in soil chemical and microbiological properties during 4 years of application of various organic residues. , 2008, Waste management.

[11]  Jinshui Wu,et al.  Measurement of soil microbial biomass C by fumigation-extraction—an automated procedure , 1990 .

[12]  A. Sundrum,et al.  Effect of cattle faeces with different microbial biomass content on soil properties, gaseous emissions and plant growth , 2012, Biology and Fertility of Soils.

[13]  Manfred Trimborn,et al.  Mitigation of greenhouse gas emissions by anaerobic digestion of cattle slurry , 2006 .

[14]  C. Liang,et al.  Microbial production of recalcitrant organic matter in global soils: implications for productivity and climate policy , 2011, Nature Reviews Microbiology.

[15]  A. Yeo,et al.  Ion Distribution in Salt-stressed Mature Zea mays Roots in Relation to Ultrastructure and Retention of Sodium , 1977 .

[16]  P. Brookes,et al.  AN EXTRACTION METHOD FOR MEASURING SOIL MICROBIAL BIOMASS C , 1987 .

[17]  R. Joergensen,et al.  Ergosterol and microbial biomass relationship in soil , 1996, Biology and Fertility of Soils.

[18]  L. Larsson,et al.  Ergosterol and fatty acids for biomass estimation of mycorrhizal fungi. , 2003, The New phytologist.

[19]  C. Emmerling,et al.  C and N turnover of fermented residues from biogas plants in soil in the presence of three different earthworm species (Lumbricus terrestris, Aporrectodea longa, Aporrectodea caliginosa) , 2008 .

[20]  H. Flessa,et al.  Shifts in amino sugar and ergosterol contents after addition of sucrose and cellulose to soil , 2007 .

[21]  H. Piepho,et al.  Response of soil fertility indices to long-term application of biogas and raw slurry under organic farming , 2015 .

[22]  U. Schmidhalter,et al.  Nitrogen availability of various biogas residues applied to ryegrass. , 2013 .

[23]  R. B. Lee.  Effects of Organic Acids on the Loss of Ions from Barley Roots , 1977 .

[24]  R. Joergensen,et al.  Quantitative assessment of the fungal contribution to microbial tissue in soil , 2008 .

[25]  P. Brookes,et al.  Chloroform fumigation and the release of soil nitrogen: A rapid direct extraction method to measure microbial biomass nitrogen in soil , 1985 .

[26]  K. Haahtela,et al.  Distribution of Antagonistic Streptomyces griseoviridis in Rhizosphere and Nonrhizosphere Sand , 1997 .

[27]  P. Brookes,et al.  Microbial biomass nitrogen measurements in soils containing large amounts of inorganic nitrogen , 1989 .

[28]  D. Powlson,et al.  A comparison of the organic matter, biomass, adenosine triphosphate and mineralizable nitrogen contents of ploughed and direct-drilled soils , 1981, The Journal of Agricultural Science.

[29]  Peter S. Curtis,et al.  NITROGEN ADDITIONS AND LITTER DECOMPOSITION: A META-ANALYSIS , 2005 .

[30]  D. Geisseler,et al.  Effects of moisture and temperature on greenhouse gas emissions and C and N leaching losses in soil treated with biogas slurry , 2011, Biology and Fertility of Soils.

[31]  E Salminen,et al.  Anaerobically digested poultry slaughterhouse wastes as fertiliser in agriculture. , 2001, Bioresource technology.

[32]  R. Joergensen,et al.  Relationships between P fractions and the microbial biomass in soils under different land use management , 2012 .

[33]  Veronica Arthurson,et al.  Closing the Global Energy and Nutrient Cycles through Application of Biogas Residue to Agricultural Land – Potential Benefits and Drawback , 2009 .

[34]  R. Joergensen,et al.  Comparison of methods for measuring heavy metals and total phosphorus in soils contaminated by different sources , 2008 .

[35]  K. Möller,et al.  Effects of anaerobic digestion on digestate nutrient availability and crop growth: A review , 2012 .

[36]  Günter Leithold,et al.  Effects of biogas digestion of clover/grass-leys, cover crops and crop residues on nitrogen cycle and crop yield in organic stockless farming systems , 2008 .

[37]  R. Joergensen,et al.  CO2 evolution and N mineralization after biogas slurry application in the field and its yield effects on spring barley , 2009 .

[38]  T. H. Christensen,et al.  Anaerobic digestion and digestate use: accounting of greenhouse gases and global warming contribution , 2009, Waste management & research : the journal of the International Solid Wastes and Public Cleansing Association, ISWA.

[39]  H. Kahiluoto,et al.  Creation of a non-mycorrhizal control for a bioassay of AM effectiveness , 2000, Mycorrhiza.

[40]  M. Wachendorf,et al.  Effects of digestates from different biogas production systems on above and belowground grass growth and the nitrogen status of the plant‐soil‐system , 2013 .

[41]  K. Möller.  Inner farm nutrient flows between arable land and permanent grassland via the stable in organic cropping systems , 2009 .

[42]  P. Ambus,et al.  Effects of digestate from anaerobically digested cattle slurry and plant materials on soil microbial community and emission of CO2 and N2O , 2013 .

[43]  R. Joergensen,et al.  Microbial colonisation of roots as a function of plant species , 2006 .