Hexavalent chromium is considered as a priority pollutant. Phytoremediation has been widely pursued for the cleanup of heavy metal from contaminated area. The success of phytoremediation is depending on two factors: metal accumulating capability and biomass production of the plants. This paper reports on the isolation and characterization of rhizobacteria having ability to promote plant growth and increase its chromium uptake. Thirty nine of bacterial isolates were obtained from the rhizosphere of wild plants (Sida sp., Sida acuta, Sida rhombifolia, Eupatorium sp., Acelypha sp, Acelypha indica, Amaranthus caudatus, Borreria sp., Leucas lavandulifolia, Eleusine indica, Pennisetum purpurium, Imperata cylindrical, and Vigna sinensis) grow well on soil contaminated by leather tanning industrial waste. Three isolates, namely I26, I30, and I37, have an ability to enhance biomass production of maize (Zea mays) by 2.3, 2.6, and 4.0 times higher compare to the uninoculated one, respectively. The isolates also have an ability to increase chromium uptake by the maize from 7 to 14 times. All of the isolates increase the accumulation of Cr in the maize root. The 16S rDNA gene sequence of the isolates relates them to Agrobacterium tumefaciens.
Industry sector exerts a negative effect on the environment. Industrial waste is often disposed to the rivers. The industry contributes to the accumulation of heavy metals in the environment. In farming sector, the accumulation of heavy metals can result in water pollution and be washed into the ground. Therefore, the farming product can be contaminated with heavy metals and they can be harmful to human health. The objective of this research was to reduce the Pb heavy metal content in paddy soil. This research was taken place in the Pb contaminated paddy soil using a randomized complete block design with three factors and three replicates. This research employed combination of inorganic fertilizer, ramie and Agrobacterium sp. I 3 or compost as a chelator to improve Pb uptake. The results showed that combination of the three treatments increased Pb uptake. The combination of chemical fertilizers, ramie with compost increased the Pb uptake of 11.93 μg/g or 45.9%. The combination of chemical fertilizers, ramie with Agrobacterium sp. I 3 resulted in the highest Pb uptake of 12.85 μg/g or 49.8%. The combination also decreased the soil Pb level by 7.8 μg/g or 23.5% of the control.
Indonesia is a country with the third largest biodiversity after Brazil and Madagascar. Of the about 325.530 species of flora and fauna globally, an estimated 25% of the world's species are found in Indonesia. Macrofauna, a land animal that plays a role in influencing the soil ecosystem has specific environmental requirements that enables it to be used as biological indicators of ecosystem conditions, mainly rice paddy ecosystem. This research is necessary owing to the demand for an easy and accurate indicator in predicting soil fertility for farmers. In addition, this study conducted in July TO August 2018 can be used as an inventory of macrofauna indigenous species that may still remain in the paddy field, Dukuhseti district. The implementation of observations was done in paddy fields in the Dukuhseti district in Pati regency, Central Java. Macro fauna specimens and soil samples were taken at various points. 121 individual macro faunas were found and divided into three phyla and 10 Order. The results showed that macro fauna diversity was not always positively correlated with soil chemical properties. Total N, available P, organic C and pH is not directly proportional to the increasingly diverse types of macro fauna in a rice field. The soil's chemical nature in the form of base saturation has a positive correlation with macro fauna diversity that makes it serve as an indicator of fertility. Base saturation in the fields can be associated with the presence of different kinds of macrofauna decomposers such as earthworms, millipedes and denitrivor. Indigenous macrofauna species was not found in the paddy fields in the Dukuhseti district due to intensive land management.
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