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| February 15, 2003 | Saturday | Zul Hijjah 13, 1423 |
Excessive use of pesticides affects soil, water quality: report
ISLAMABAD, Feb 14: As a result of over-exploitation and degradation of soil and water in the Punjab province, the growth rate of crops output declined by 0.8 per cent reaching three per cent per annum during 1974-1995, says a study.
According to the report presented by Khalid Mustafa and Zulfiqar Ahmad Gill, the decline in productivity is an outcome of the green revolution approach, which paradoxically still sustains the high population growth rate of the country.
As the demographic numbers continue to multiply, albeit at reduced rate, the agriculture of Punjab might not be able to fulfil food and industrial needs of the country indefinitely, the report added.
The report said Punjab was going through “second generation problems” associated with green revolution of which a major characteristic was mono-cropping.
High use of fertilizers, often inappropriate for given soil conditions and crop requirements, and poisons has led to increased resistance by the pests and spread of diseases among farmers, particularly women cotton pickers, it added.
The Punjab province showed spectacular progress in farm sector over the three decades under review. The yield of all crops increased at an average rate of 1.8 per cent per annum led by wheat and cotton.
Increased availability of water following construction of Mangla and Tarbela reservoirs triggered double-crop cultivation on the same land. Overall, the cropping intensity increased by about 30 per cent.
However, the jump in agricultural outputs was achieved at a huge price in terms of the quality of water and land.
The use of fertilizers in Punjab jumped from an average of 14kg of nutrients per hectare in mid-70’s to an average of 86kg per hectare during mid-80’s.
Pesticide use also increased rapidly, especially for cotton, after mid-80’s.
Another important factor in this regard was the mushroom growth of private tubewells, a process propelled by energy subsidised by self-serving policies of feudal and bureaucratic system.
Therefore, only few large landowners controlling majority of land and monopolising the agricultural inputs market largely appropriated the benefits channelled through rural institutions.
Due to these reasons, the successive governments largely ignored the warnings by environmentalists and perceptive scientists against the strain of indiscriminate pumping of ground water and use to chemicals on basic resources.
The soil and water quality in the Punjab deteriorated over time. Average soil organic matter, which was already lower than one per cent during early 1970’s, deteriorated further at an average annual rate of 2.3 per cent. By 1990’s, it declined by over 33 per cent.
The deterioration of tubewell water quality advanced at a sufficiently high rate to cause serious concern among scientists. This was reflected in the increase in carbonate and electro-conductivity. Residual carbonates almost doubled over the years.
The total storage capacity of the major water reservoirs too has declined over time, mainly due to silting. The problem has been compounded by severe drought conditions leading to ever greater reliance on tubewells.
The number of tubewells jumped almost three-fold to 473,667 in Punjab and the quantity of water pumped by these increased from 31.25 million acre feet (MAF) in 1980-81 to 44.55 MAF in 2000-01.
About 70 per cent of tubewells were found to be pumping hazardous water. Irrigation with this water has aggravated soil salinity/sodication, worsening the produce quality/shelf life.
High population growth in Pakistan takes heavy toll of agricultural resources in the form of pollution.
The effluent from cities is ultimately discharged into sewage system and from there into rivers due to the shortsighted expediency of farmers as well as the government.
The sewage water has contaminated the soils and crops with heavy metals and high salt content.
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