Influence of different acid and alkaline cleaning agents on the effects of irrigation of synthetic dairy factory effluent on soil quality, ryegrass growth and nutrient uptake.
The aim of this study was to examine the effects of replacement of phosphoric acid with nitric or acetic acid, and replacement of NaOH with KOH, as cleaning agents in dairy factories, on the effects that irrigation of dairy factory effluent (DFE) has on the soil-plant system. A 16-week greenhouse study was carried out in which the effects of addition of synthetic dairy factory effluent containing (a) milk residues alone or milk residues plus (b) H(3)PO(4)/NaOH, (c) H(3)PO(4)/HNO(3)/NaOH or (d) CH(3)COOH/KOH, on soil's chemical, physical and microbial properties and perennial ryegrass growth and nutrient uptake were investigated. The cumulative effect of DFE addition was to increase exchangeable Na, K, Ca, Mg, exchangeable sodium percentage, microbial biomass C and N and basal respiration in the soil. Dry matter yields of ryegrass were increased by additions of DFE other than that containing CH(3)COOH. Plant uptake of P, Ca and Mg was in the same order as their inputs in DFE but for Na; inputs were an order of magnitude greater than plant uptake. Replacement of NaOH by KOH resulted in increased accumulation of exchangeable K. The effects of added NaOH and KOH on promoting breakdown of soil aggregates during wet sieving (and formation of a < 0.25 mm size class) were similar. Replacement of H(2)PO(4) by HNO(3) is a viable but CH(3)COOH appears to have detrimental effects on plant growth. Replacement of NaOH by KOH lowers the likelihood of phytotoxic effects of Na, but K and Na have similar effects on disaggregation.
School of Agriculture and Food Sciences/CRC CARE, The University of Queensland, St Lucia, 4072 QLD, Australia.
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Liu
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Haynes
D019342:Acetic Acid / Q000032:analysis / Q000737:chemistry; D003612:Dairying; D003902:Detergents / Q000032:analysis / Q000737:chemistry*; D004323:Drainage, Sanitary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D006878:Hydroxides / Q000737:chemistry; D008129:Lolium / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D017942:Nitric Acid / Q000032:analysis / Q000737:chemistry; D009584:Nitrogen / Q000032:analysis / Q000378:metabolism; D010756:Phosphoric Acids / Q000032:analysis / Q000737:chemistry; D010758:Phosphorus / Q000032:analysis / Q000378:metabolism; D017680:Potassium Compounds / Q000737:chemistry; D018570:Risk Assessment; D012972:Sodium Hydroxide / Q000737:chemistry; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism / Q000633:toxicity
D003902:Detergents; D006878:Hydroxides; D010756:Phosphoric Acids; D017680:Potassium Compounds; D012987:Soil; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D017942:Nitric Acid; D012972:Sodium Hydroxide; C030242:phosphoric acid; D009584:Nitrogen; D019342:Acetic Acid; C029943:potassium hydroxide