The use of contaminated fertilizers with nutrient deficiencies over the years affected soil’s fertility and caused losses to farmers in Bangladesh, soil scientists told New Age.
They call them ‘substandard fertilizers’.
They called it a matter of concern that most of the farmers were not even aware that nutrient deficiencies and heavy metal contamination in fertilizers, sold to them, is quite widespread.
Soil scientists said that it was the mandatory responsibility of the Department of Agricultural Extension to enforce fertilizer standards and make the farmers aware about the quality of fertilizers available in the market.
They said that the DAE had been failing to discharge its mandatory responsibilities on all these and other counts including monitoring the fertilizer market and publishing the findings.
They said that they failed to understand why the DAE never publishes its findings relating to the quality of fertilizers sold to non-suspecting farmers.
Ultimately, they said, that the responsibility falls on the government which continuously sets higher crop production targets for the farmers.
Farmers find it quite puzzling having to use the fertilizers in increasing quantities to meet the targets of production, they said.
‘The use of substandard fertilizers affects the farmers and their land in several ways,’ Bangladesh Agricultural Research Institute’s senior scientific officer Nazim Uddin told New Age.
The first impact is economic, he said, as fertilizers with low nutrient contents force farmers to buy more fertilizers to get enough crop nutrients.
Substandard fertilizers would also reduce crop productions, affect the food quality and make it elusive for the government to attain its ambitious goal of national food security, Nazim said.
The 3rd impact of substandard fertilizers, he said would be on soil health.
Sher-e-Bangla Agricultural University agricultural chemistry professor Abdur Razzaque said the use of substandard fertilizers would cause ‘soil poisoning.’
‘Nobody seems to care about the challenging situation our future generations would face to produce crops from poisoned soil,’ said Razzaque.
According to DAE’s fertilizer management wing, the tests it had done in 10 months until April showed that 40 out of 200 fertilizer samples, collected from 20 districts, were substandard.
DAE’s tests only checks
for key nutrients in fertilizer samples.
DAE never tried to find out toxicity and the presence of chemicals in fertilizers and in what proportions.
DAE is also unwilling to share the levels of nutrient deficiencies in fertilizer samples they had tested.
One came to learn about the level and extent of nutrient deficiencies in fertilizers from the test report of 434 samples of seven types of fertilizers done by the Bangladesh Institute of Nuclear Agriculture in two years until June.
The samples were sent to BINA by DAE field officers at Mymensngih, Jamalpur, Tangail, Sherpur, Gopalpur, Madhupur and Kalihati.
BINA found 76 to 89 per cent samples of tri superphosphate (TSP), Di Ammonium Phosphate, Boron and Gypsum fertilizers to be substandard.
Hundred per cent samples of muriate of potash (MOP), zinc sulfate and magnesium sulfate were found to be substandard.
BINA scientists involved in analyzing samples said that phosphate was present in the range between 43.33 per cent and 45.92 per cent in 53 of 67 TSP fertilizer samples.
Pure TSP fertilizer contains 46 per cent phosphate.
In 53 of 66 samples of boron fertilizers boron content was found in the range from 0.22 per cent to 16.79 per cent, said the scientists. Boron fertilizer is not considered pure unless it contains 17.5 per cent boron in it.
In all the 68 MOP fertilizer samples potash content ranged between 51.08 per cent and 58.28 per cent whereas pure MOP fertilizer should have 60 per cent of potash in it.
Tests at the BINA laboratory also found all the 58 samples of two variations of zinc sulfate fertilizer substandard. In zinc sulfate monohydrate zinc content was present in the range between 8.94 per cent and 32.12 per cent. Pure zinc sulfate should contain 36 per cent zinc in it.
In samples of zinc sulfate heptahydrate zinc content was present in the range from 0.1 per cent to 20.37 per cent. Pure sample of the fertilizer should have 23 per cent zinc content in it.
‘Lack of purity means presence of bad stuff,’ said SAU professor Razzaque.
He said that there was a high chance of TSP being contaminated with toxic element like chromium because of from where it is sourced: Rock phosphate.
Razzaque is also worried about TSP being imported from China, a country having a record of supplying substandard products, especially to countries like Bangladesh where monitoring is very poor.
With regard to MOP fertilizer, Razzaque said, improperly refined MOP may contain salt which may contribute to raising salinity in soils.
Former BARI director general Shahidul Islam found contamination in 75 per cent of zinc sulfate fertilizers tested as part of a three-year-long USAID funded project that ended last year.
Many of the samples were contaminated with heavy metals like arsenic, lead, cadmium, mercury and nickel, Shahid said.
In 2010 an SRDI survey revealed that about 40 per cent of urea and non-urea fertilizers were adulterated and contained with highest levels of heavy metals.
In 2013, the SRDI revealed similar findings with 40 per cent of fertilizers it had tested and noted an increase in adulteration in samples of urea fertilizer, the most used fertilizer in the country.
Dhaka University soil, water and environment professor Sirajul Hoque said that he found high concentration of cadmium and lead in zinc sulfate fertilizers manufactured locally in 2009.
In one of the samples of Zinc sulfate imported from China, Siraj found 43,000 ppm cadmium whereas the permissible limit of it is 10 ppm.
BARI scientist Nazim said researches regularly find urea fertilizer adulterated with salt, phosphate fertilizers with cement-coated-pebbles, and MOP fertilizers with brick crusts.
‘Inert material ratio in soil would spike from use of such fertilizers, gradually affecting biological activities in soil,’ Nazim said.
Use of fertilizer in Bangladesh increased many fold since the country began using it in the 1950s. Fertilizer use tripled from 220 kg per hectare in 1990 to about 600 kg at the moment, excluding the use of fertilizers smuggled from India.
DU soil science professor Sirajul Hoque emphasized on integrated fertilizer management to bring the rapidly growing dependence on chemical fertilizers under control.
‘We need to feed our soil instead of feeding crops for achieving a sustainable growth in agricultural production,’ Sirajul said.
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