Location: National Soil Erosion Research Laboratory
Title: Soil surface sealing by liquid dairy manure affects saturated hydraulic conductivity of Brazilian OxisolsAuthor
FERNANDA CHEROBIM, VEREDIANA - UNIVERSIDADE FEDERAL DO PARANA | |
FAVARETTO, NERILDE - UNIVERSIDADE FEDERAL DO PARANA | |
DE FREITAS MELO, VANDER - UNIVERSIDADE FEDERAL DO PARANA | |
BARTH, GABRIEL - UNIVERSIDADE FEDERAL DO PARANA | |
HUANG, CHI HUA |
Submitted to: Agricultural Water Management
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 3/10/2018 Publication Date: 3/15/2018 Citation: Fernanda Cherobim, V., Favaretto, N., De Freitas Melo, V., Barth, G., Huang, C. 2018. Soil surface sealing by liquid dairy manure affects saturated hydraulic conductivity of Brazilian Oxisols. Agricultural Water Management. 203:193-196. https://doi.org/10.1016/j.agwat.2018.03.016. DOI: https://doi.org/10.1016/j.agwat.2018.03.016 Interpretive Summary: Applying liquid manures on the soil surface may create a seal layer that reduces water entry into the soil. Surface sealing can be caused by both physical filling of soil pores and chemical dispersion where soil particles are dispersed into smaller factions. In this research, we evaluated sealing processes on a sandy clay loam and a clayey soil after liquid manure application (LDM). Factors affecting surface sealing, such as LDM dosage, total solids content of LDM, straw cover, and time after LDM application, were studied. We found most of the sealing, i.e., 93%, was by physical filling of pores while chemical dispersion only contributed very minute effect (7%). The degree of surface sealing, as indicated by the reduction in hydraulic conductivity, increased as the application dosage and the solid content in the liquid manure were increased. A straw cover on the soil surface reduced surface sealing and the clayey soil was more susceptible to surface sealing than the sandy soil. The results are useful to those making land application of liquid manures to ensure a proper pre-treatment, scheduling and site selection of liquid manure application to minimize detrimental water quality effects. Technical Abstract: The liquid manure applied on the soil surface may alter its hydraulic conductivity by surface sealing. In this study, we evaluated the chemical and physical mechanisms of surface sealing process acting in sandy clay loam and clayey soils after liquid manure application (LDM). Factors affecting surface sealing such as LDM dosage, total solids content of LDM, straw cover, and time after LDM application, were also studied. The saturated hydraulic conductivity (Ksat) was determined before and 24 hours and 7 days after LDM application, and the sealing index was calculated. The liquid dairy manure application on soil surface promoted the surface sealing in both soils (around 93 % of sealing surface was due to physical mechanism and around 7 % to chemical mechanism). The application of LDM with 9.4 % TS (total solids) promoted greater sealing index (greater surface sealing) compared to LDM with 0 % TS, mainly in the interval of 24 hours after LDM application. Greater surface sealing was also observed with greater LDM dose (60 m3 ha-1). The soil cover with 5 Mg ha-1 of straw resulted the lower sealing index (lower surface sealing) than soil with 0 Mg ha-1 of straw. The sealing index was greater in the interval of 24 hours after LDM application for all treatments (solids content, LDM doses, soil cover) in both soils (clayey and sandy clay loam). The clayey soil was more susceptible to surface sealing after LDM application. The results are useful to those managing LDM on scheduling application to minimize detrimental effects. |