Status: this discussion paper is a preprint. It has been under review for the journal SOIL (SOIL). The manuscript was not accepted for further review after discussion.
Ecological sanitation products reuse for agriculture in Sahel: effects on soil properties
D. Sangare2,1,B. Sawadogo1,M. Sou/Dakoure1,D. M. S. Ouedraogo1,N. Hijikata3,H. Yacouba1,M. Bonzi4,and L. Coulibaly2D. Sangare et al.D. Sangare2,1,B. Sawadogo1,M. Sou/Dakoure1,D. M. S. Ouedraogo1,N. Hijikata3,H. Yacouba1,M. Bonzi4,and L. Coulibaly2
Received: 26 Feb 2015 – Discussion started: 31 Mar 2015
Abstract. The sanitary products (i.e toilet compost, urine, and greywater) from resource oriented sanitation are a low-cost alternative to chemical fertilizers and irrigation water for poor communities in dry areas. However, if these products are not managed carefully, increased soil salinity and sodium accumulation could occur. The aim of this study was to assess the effects of these products at different combinations on the properties of cultivated soil and on okra plant productivity. The treatments were: (1) fresh dam water (FDW) as a negative control, (2) FDW plus chemical fertilizer (i.e.NPK) (FDW + NPK) as a positive control, (3) treated greywater (TGW), (4) FDW plus Urine/Toilet Compost (UTC) (FDW + UTC), (5) TGW + UTC, (6) TGW + NPK. Effects on okra productivity were assessed by measuring the fresh fruit yield whereas effects on soil were evaluated through measurements of electrical conductivity (EC), sodium adsorption ratio (SAR) and total organic carbon (TOC) at various depths. Results showed that the yields obtained with TGW (0.71 t ha−1) and TGW + UTC (0.67 t ha−1) were significantly higher than the yields obtained with the positive control FDW + NPK (0.22 t ha−1) meaning that the fertilizer value of the sanitary products was higher than that of chemical fertilizer. Concerning effects on soil, SAR values increased significantly in plots treated by TGW (8.86 ± 1.52) and TGW + UTC (10.55 ± 1.85) compared to plots fertilized with FDW (5.61 ± 1.45) and FDW + NPK (2.71 ± 0.67). The TOC of plots treated with TGW + UTC (6.09 ± 0.99 g kg−1) was significantly higher than those of FDW + NPK (4.46 ± 0.22 g kg−1). Combined sanitary products from resource oriented sanitation can be reused as a nutrient source and water for food production, provided that soil salinity is monitored and the soil has high drainage capacity.
How to cite. Sangare, D., Sawadogo, B., Sou/Dakoure, M., Ouedraogo, D. M. S., Hijikata, N., Yacouba, H., Bonzi, M., and Coulibaly, L.: Ecological sanitation products reuse for agriculture in Sahel: effects on soil properties, SOIL Discuss., 2, 291–322, https://doi.org/10.5194/soild-2-291-2015, 2015.
Closed-loop sanitation systems provide a way to reduce health risks while also recovering useful nutrients for agriculture in Sahelian areas. However, the soil salinity issue is significant because urine and/or greywater, which are potential salt sources. There is very limited information on soil salinity and sodicity from greywater in conjunction with urine/compost. These products can be reused as a nutrient source and water for food production, provided that soil salinity is monitored.
Closed-loop sanitation systems provide a way to reduce health risks while also recovering useful...