Evaluation of the potential for biosolids obtained from wastewater treatment for agricultural use and their effect on cultivation of red radish (Raphanus sativus L)

This study was conducted in waste water treatment plant The Salitre, in Bogota, to evaluate the potential of the waste water treatment subproduct biosolids for application in agriculture by means of quantifying growth, development and production of cultivation of red radish, and to establish a possible alternative to the problem of final disposition of 3900 tons of this material generated monthly in the waste water treatment plant. The experimental design employed was a random blocks design, with five treatments and three replications, arranged in 2 m x 2 m plots. the treatments corresponded to mixtures of biosolids with soil in the following proportions: 100 % biosolid (equivalent to 294 ton ha-1), 75 % biosolid (220 ton ha-1), 50 % biosolid (147 ton ha-1), 25 % biosolid (73 ton ha-1) and. 100 % soil. Red radish raphanus sativus l. was planted. the variables evaluated were: germination percentage, dry weight of leaves and. roots, plant length, foliar area and production. Also, the accumulation of trace was measured in the harvested radishes, to determine risks of consumption. The results showed that the 50 % biosolid and 25 % biosolid, treatments were those that most favored growth, development and. production of cultivation radish, while the 75 % biosolid and 100 % biosolid treatments, showed lower development growth and production of the cultivar. The 100 % biosolid treatment resulted in low germination and also did not show root accumulation, that is the harvested product. The levels of accumulation of heavy metals surpassed the maximum levels with the 75 % biosolid and 100 % biosolid treatment. It was shown that the use of the biosolids in agriculture can produce a great risk, because despite having high nutrient (C,N, P, Ca, Na, Fe y Zn) and organic matter content, it also may slow growth and production of radish plants