Mnkeni P.N.S., Kutu F.R., Muchaonyerwa P., Austin L.M.
Department of Agronomy, Faculty of Science and Agriculture, University of Fort Hare, PB X1314, Alice 5700, South Africa; CSIR Built Environment Unit., Pretoria, South Africa
Mnkeni, P.N.S., Department of Agronomy, Faculty of Science and Agriculture, University of Fort Hare, PB X1314, Alice 5700, South Africa; Kutu, F.R., Department of Agronomy, Faculty of Science and Agriculture, University of Fort Hare, PB X1314, Alice 5700, South Africa; Muchaonyerwa, P., Department of Agronomy, Faculty of Science and Agriculture, University of Fort Hare, PB X1314, Alice 5700, South Africa; Austin, L.M., CSIR Built Environment Unit., Pretoria, South Africa
The introduction of ecological sanitation (ECOSAN) toilets in South Africa has created opportunities for safer sanitation and recycling of human excreta, as fertilizers, in rural and peri-urban areas. A study was carried out to evaluate the fertilizer value of human urine (0 to 400 kg N ha-1) for maize and tomato, compared to urea, in a tunnel house. Dry matter yield of both maize and tomato, harvested at 9 and 10 weeks after planting, respectively, increased with increasing N rate (both as urine or urea) up to 200 kg N ha-1. Urea reduced soil electrical conductivity (EC) whereas urine increased it. Leaf tissue Na, in both crops, also increased with urine application. A follow-up study was carried out with two crops with contrasting sensitivity to salinity and using a wider range of N application (0 to 800 kg N ha-1). The results indicated increased root and leaf dry-matter yield of beetroot (tolerant to salinity) with increased urine rates up to the highest rate of 800 kg N ha-1, whereas the leaf and root dry-matter yield of carrot, which is sensitive to salinity, peaked at the low urine application rate of 50 kg N ha-1. Soil EC increased with urine application up to 4.64 and 13.35 mS cm-1, under beetroot and carrot, respectively. Generally the results showed that human urine compared well with urea as a source of N for crops but optimum rates depend on the sensitivity of the crops to soil salinity, which should be monitored where human urine is regularly used for fertilizing crops. © ISWA 2008.
Crops; Fertilizers; Nutrients; Recycling; Sanitation; Ecological sanitation; Human excreta; Wastes; organic fertilizer; urea; Crops; Fertilizers; Nutrients; Recycling; Sanitation; Wastes; anthropogenic source; dry matter; electrical conductivity; fertilizer; maize; nutrient; recycling; salinity; sanitation; soil property; urine; vegetable; article; beetroot; biomass production; carrot; controlled study; crop production; ecological procedures; electric conductivity; environmental sanitation; fertilizer application; human; maize; male; nutrient availability; nutrient supply; plant leaf; plant root; priority journal; salinity; soil fertilization; soil property; South Africa; tomato; urine; Biomass; Electric Conductivity; Fertilizers; Hydrogen-Ion Concentration; Nitrogen; Plant Roots; Plant Shoots; Sodium; South Africa; Urine; Vegetables; Zea mays; Africa; Eastern Cape; South Africa; Southern Africa; Sub-Saharan Africa; Daucus carota; Lycopersicon esculentum; Zea mays