Determination of heavy metal profiles in Neem leaves (Azadirachta indica A) along some major streets in Minna metropolis Nigeria

Neem (Azadirachta indica) leaves collected from some major streets in Minna metropolis were determined for their heavy metal contamination using Atomic Absorption spectrophotometer (AAS). The results showed that the concentrations of analysed heavy metals along all the sampling route ranged from 14.5±1.15- 71.0 ± 6.17 µg/g Mn; 303.0±12.23-765.0 ± 19.27 µg/g Fe; 5.8± 0.55-40.0± 3.35 µg/g Cu; 59.4±3.50-361.0±12.53 µg/g Zn, with Fe > Zn > Mn > Cu along the various routes, while Cr, Cd and Pb were below detectable limit in all the samples. The result from this study indicate that the metal ion concentration in neem leaves along the various route studied were within the permissible level as recommended by WHO for plants to be used as food or for medicinal purposes and therefore will not contribute any toxicity or harmful effect to human health when taken orally or in the form of tea or for medicinal purposes or as part of diet. Keywords: Neem, Azadirachta indica, contamination, spectrophotometer, concentration toxicit

Global Agriculture as an Energy Transfer System and the Energy Yield of World Agriculture 1961–2013

The global agricultural system is an energy transfer system converting solar radiation to stored chemical energy in the biosphere through photosynthesis and animal metabolism. Stored energy in the agricultural system is principally in the form of carbohydrates, proteins, fats, and oils that humanity appropriates for food, fiber, and fuel. The total annual production of global agriculture was tabulated using data from the Food and Agriculture Organization from 1961 to 2013. Annual agricultural production for each agricultural item (T y−1) was converted to energy yield (kJ y−1) utilizing published proximate analyses (% moisture, % protein, % carbohydrate, % fat/lipid, and % ash). Global agricultural energy yield grew linearly over the 1961–2002 interval. From 2002 onward, global agricultural energy yield also grew linearly, but at a rate 2 times the 1961–2002 rate. Overall, agricultural energy yield more than tripled from 1961 to 2013. Unsurprisingly, energy output of global crops dominated, averaging 85.5 ± 0.4% of total energy output. Livestock and poultry production averaged 13.6 ± 0.4% of annual agricultural energy output, while world fisheries and aquaculture averaged 0.8 ± 0.1% of global energy output. From 1961 to 2013, the feeding potential of global agricultural energy yield exceeded the human metabolic energy requirement by an average multiple of 2.1 ± 0.18. Thus, agricultural production is more than sufficient to feed “The Global Mouth” into the future, and feeding world population is not a production problem per se. Instead, the inability of global agriculture to meet worldwide food requirements results from systemic energy losses associated with significant global food waste, diversion of food energy as feed to livestock and poultry, and appropriation of primary agricultural output for biofuels synthesis