Concentrations of Trace Elements in Organic Fertilizers and Animal Manures and Feeds and Cadmium Contamination in Herbal Tea (Gynostemma pentaphyllum Makino).
Thailand is predominantly an agriculture-based country. Organic farming is enlisted as an important national agenda to promote food safety and international export. The present study aimed to determine the concentrations of trace elements in commercial organic fertilizers (fermented and nonfermented) composed of pig and cattle manures available in Thailand. Pig and cattle manures as well as animal feeds were also collected from either animal farms or markets. The results were compared to the literature data from other countries. Fermented fertilizer composed of pig manure contained higher concentrations of nitrogen (N) and phosphorus (P) than fertilizer composed of cattle manure. High concentrations of copper (Cu) and zinc (Zn) were also found in fertilizers and manures. Some organic fertilizers had high concentrations of arsenic (As), cadmium (Cd), and lead (Pb). The range of As concentration in these fertilizers was 0.50-24.4 mg/kg, whereas the ranges of Cd and Pb were 0.10-11.4 and 1.13-126 mg/kg, respectively. Moreover, pig manure contained As and Cd (15.7 and 4.59 mg/kg, respectively), higher than their levels in cattle manure (1.95 and 0.16 mg/kg, respectively). The use of pig manure as soil supplement also resulted in high Cd contamination in herbal tea (Gynostemma pentaphyllum Makino; GP). The Cd concentration in GP plants positively correlated with the Cd concentration in the soil. Therefore, the application of some organic fertilizers or animal manures to agricultural soil could increase some potentially toxic elements in soil, which may be absorbed by plants and, thus, increase the risk of contamination in agricultural products.
Immobilizing Arsenic and Copper Ions in Manure Using a Nanocomposite.
Livestock manure (Man) commonly contains a certain quantity of heavy metal ions, such as arsenic (As) and copper (Cu) ions, resulting in a high risk on soil contamination. To solve this problem, heavy metal of manure was immobilized into sodium carbonate/biosilica/attapulgite composite (Na2CO3/BioSi/Attp), which was developed using a nanocomposite consisting of anhydrous sodium carbonate (Na2CO3), straw ash-based biochar and biosilica (BioSi), and attapulgite (Attp). When Na2CO3/BioSi/Attp was mixed with Man/AsCu, the obtained nanocomposite (Na2CO3/BioSi/Attp/Man/AsCu) with a porous nano-network structure could effectively control the release of As and Cu ions from manure through adsorption and chemical reaction. Meanwhile, a pot experiment indicated that Na2CO3/BioSi/Attp/Man/AsCu could increase the pH value of acid soil, promote the growth of rice, and significantly decrease the uptake of As and Cu ions by rice. Therefore, this work provides a promising approach to immobilize heavy metal ions in manure and, thus, lower the contamination risk to the environment. Na2CO3, BioSi, and Attp powders were mixed evenly with a weight ratio of WNa2CO3/WBioSi/WAttp = 3:1:2.
Carnival of Shame: Doctorow and the Rosenbergs
“Literature can turn language, for the moment at least, against the sentence of death.” Considering the national and international furor provoked by the sensational early 1950's “atom spy” trial and execution of Julius and Ethel Rosenberg, one may be surprised that these dramatic and traumatic events have not inspired more literary artistry than they have. But a prominent playwright, Arthur Miller, did write The Crucible (produced in 1953) in part as a response to the rabid McCarthyism of that era, and two highly regarded novelists in a later decade composed ambitious novels drawing directly on the Rosenberg affair: E. L. Doctorow in The Book of Daniel (1971) and Robert Coover in The Public Burning (1977). In 1987, Sidney Lumet produced the little noticed film Daniel, based on Doctorow's novel, and still more recently Tony Kushner's Pulitzer Prize-winning play, Angels in America, with Ethel Rosenberg as one of the characters, has been playing on Broadway.