Naseer Abdul-Jabbar AlSaadie(1) Adnan Shibar falih(1) and Raghaa Mouhamad*(1)
(1). Agriculture Research Directorate, Ministry of Science and Technology, Baghdad, Iraq.
(*Corresponding author: Raghaa Mouhamad. Email: naseeralsaadie61@gmail.com).
Received: 14/04/2019 Accepted: 01/06/2019
Abstract
Several samples were collected from the mineral fertilizers i.e. phosphate, nitrogen and potash that commonly used in Iraq, as well as samples of different soils with different chemical and physical properties, and tomato plants which were grown in it, in two regions i.e. Abu Ghraib and Jadriya. These two regions represent most of the soils of Iraq, with different periods of culture. The results of statistical analysis showed high significant differences present among accumulation of heavy metals rates in soils and tomato fruits according to varying culture dates and soil type. The overall average soil content of elements (Pb, Cd, Co, Ni) for a chemical fertilizer use periods 5, 10 and 25 years, were 7.6, 9.6 and 12.7 mg.kg-1 f respectively. The results showed that the average concentration of heavy metals (Pb, Cd, Co, Ni) for all periods of mineral fertilizer addition in Abu Ghraib (clay) and Jadriya (loam) were 11.0 and 8.9 mg kg-1 respectively. Overall mean of all heavy elements content in tomato fruits for the studied time periods were 0.733, 0.919 and 1.49 mg.kg-1 respectively, while the concentration of these elements in tomato fruits that grown in the two soil regions for all periods of fertilization were 1.18 and 0.909 mg.kg-1 respectively. Results also showed the existence of a positive significant correlation at 1% level of probability between soil content of heavy metals and culture periods, and heavy metals concentration in tomato fruits that grown in those soils. The average percentage of the cumulative increase of heavy metals (Ni, Co, Cd and Pb) as accompaniment impurities in the mineral fertilizers in soils amounted to 65.8, 29.8, 0.35 and 37.4% per year, while the increase percentage in tomato fruits were 15.6, 1.9, 0.15 and 2.4% for each of the above element respectively. Results also showed the presence of a significant effect between the fertilizer type and the content of heavy metals contaminated values. In general, depending fertilizer’s content of contaminated heavy metals, the fertilizer can be arranged as follows: Urea U < MAP fertilizer < NPK fertilizer < DAP fertilizer < Triple Super Phosphate TSP.
Key words: Mineral fertilizers, Heavy metals, Soil properties, Tomato.
Full Paper in Arabic: PDF