Volume No. 13 Issue No.: 02 Page No.: 116-124 October-December 2018

 

IMPACT OF BIOCHAR APPLICATION ON SOIL MICRO BIOLOGICAL ATTRIBUTES UNDER CORN PLANT CULTURE SUBJECTED TO WATER DEFICIT STRESS

 

Aliasgharzad N.*, Javani M. and Oustan S.

University of Tabriz, Faculty of Agriculture, Department of Soil Science, Tabriz, (IRAN)

 

Received on : May 29, 2018

 

ABSTRACT

 

Biochar as a stable carbon source can affect soil properties including microbiological attributes. The effects of biochar may also be influenced by plant growth and water deficit stress. In a greenhouse study, the biochar at three levels of 0, 1 and 2% w/w was thoroughly mixed with soil. Half of pots were planted with corn seeds (Zea mays L. Single Cross 704) and the rest were left un-cultured. Soil moisture levels of 80-90% FC (S0), 60-70% FC (S1) and 40-50% Fc (S2) were applied to the pots by daily weighing and watering. After two months, the soil basal and substrate induced respirations (BS and SIR), microbial biomass carbon, nitrogen and phosphorus (MBC, MBN and MBP) were determined. Metabolic and microbial quotients (qCO2 and qmic) were also calculated as microbial eco-physiologic indices. The BS in un-cultured pots was markedly enhanced by increasing biochar level but there was no alteration in cultured pots with increasing biochar level, although the BS was higher in cultured than un-cultured pot at comparable biochar levels. SIR was adversely affected by increasing water deficit stress in un-cultured pots but it was not affected in cultured pots. At soil moisture levels of S0 and S1 the addition of biochar caused an increase in MBC. Biochar levels had no significant effects on MBN at S0 and S1 but a marked increase in MBN was recorded at S2 with 2% biochar amendment. MBP was not affected by water deficit stress or biochar addition. qCO2 tended to increase by increasing water deficit stress but biochar at 1% level alleviated this index at all moisture levels. Both biochar levels of 1 and 2% exhibited positive effects on qmic at S0 and S1, but biochar levels had no pronounced impact on qmic at S2.

 

Keywords : Biochar, Metabolic quotient, Microbial biomass carbon, Soil respiration

 

 

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