Heavy metal content in the leaves of Crassocephalum crepidioides due to the application of various types of manure

In Indonesia, vegetable farmers use manure to increase production. In fact, one of the sources of heavy metal pollution on agricultural land is the use of manure. This study, therefore, aims to determine the content of heavy metals in the leaves of Crassocephalum crepidioides , due to fertilization, involving the use of several types of manure. Furthermore, it is possible to apply the results in the establishment of dose limiting policies for vegetable crops, in an attempt to prevent dangers to the consumer. The tested sources consisted of chicken, goat, and cow manure, as well as a control (without manure), and each was applied at a dose of 20 tons/Ha. Meanwhile, the third leaf of the upper part of the plant was analyzed using Atomic Absorption Spectrophotometer (AAS), to determine Cu, Pb, Zn and Cd. The results showed the leaves of Crassocephalum crepidioides fertilized with 20 tons/Ha of chicken manure, goat manure and cattle manure had low heavy metal (below the set threshold of 50, 100-400, and 5-30 ppm for Pb, Zn and Cd, respectively). However, at a dose of 20 tons/Ha, the leaves pastored with goat and cow manure had a high content of Cu (209.78 and 530.90 ppm) than control and chicken manure (67,92 and 92,68 ppm), which are higher than the established threshold. Meanwhile, those fertilized with chicken compost, had better area and plant height value, compared to the goat and cow sources.