The effects of whey application on the soil biologicalproperties and plant growth

Abstract

Whey is an industrial dairy by-product. Whey proteins present in whey are valuablefunctional ingredients with a variety of applications. Because of high investment andmanagement costs, many medium and small-scale cheese manufacturing plants choosethe way to waste whey by discharging it to land without refining while large companiesprefer to evaluate it. In this experiment were investigated the effects of wheyapplication on some growth parameters of test plant and soil biological properties. Forthis purpose, greenhouse experiment was conducted to determine the effects ofdifferent whey powder solution (6% dry matter) such as no demineralized wheypowder (NDWP), 50% demineralized whey powder (50% DWP) and whey proteinpowder (WPP) on maize growth and biological properties of soils using increasingapplication rates (0, 50, 100, 150 and 200 ml/kg) as three replication. At the end of thestudy generally, all whey treatments influenced the soil microbiological properties incomparison with the control, indicating activation by microorganisms. The addition ofdifferent doses of different whey solutions caused a rapid and significant increase inmicrobial biomass C, soil respiration, dehydrogenase activity and catalase activity insoil; this increase was especially noticeable in soils treated with NDWP and 50% DWP.Similarly, addition of 50% DWP to the soil increased values of plant height, fresh plantweight and fresh root weight compared to the control and other whey. Whey has apositive effect on soil biological properties. In conclusion, we can say that this wasteproduct, which has high nutrient element content, could be used in fertilizationpractices especially as a nitrogen source and multi-perspective studies need to becarried out on this topic.