 |
|
| AGRICULTURE TRIBUNE |
|
Tubewells, drilling for deep trouble
Avian influenza: scare of the foul fowls Bird flu scare in North-East Study casts doubts over Bt cotton benefits... |
|
|
Tubewells, drilling for deep trouble Merely 57 per cent of the area was covered by tubewell irrigation two decades ago. Post-2000, when 75 per cent of Punjab is tubewell irrigated, deep tubewells have become an agrarian necessity given the way the static water level (SWL) is falling. The water table is hurtling down not by centimetres or inches but, hold your breath, metres! And this is making the municipal councils scared, geologists tense and farmers petrified. Plummeting
water table The water level was 12 m in Jattpur village, Balachaur block, in 1996. It is 20 m now. Similarly the level was 14 m in Takhatgarh village of the same block in 1992. It is 18 m at present. Hassanpur village, Derabassi block, has a current SWL of 60 m. It was 36 m 10 years ago. Mr Gurdarshan Singh of Gurnam Singh and Company, an international-level drilling company, says: “We have been in this trade since long. To ensure good water discharge, we have to dig 300 to 375 m in Derabassi block. Earlier, 120 m of drilling used to be sufficient.” He says that the water level is going down by 3 m in Derabassi and by 2 m in Chandigarh annually. If this alarms you, listen to what Central Ground Water Board (CGWB) experts have to say. According to Mr D.S. Saini, Director, CGWB, Chandigarh, the water level has gone down by 40 m in Lalru, 30 m in Chandigarh and 40 meters in Derabassi. “A detailed report is in the offing,” says a pragmatic Mr Saini. Already, four tubewells in Manimajra, a town under the Chandigarh Administration, have dried up and the level in a number of other wells has gone down. Deep tubewells Rampant drilling of deep tubewells is a menace and installing a deep tubewell where a shallow one may suffice, amounts to compounding the danger. Hydrogeologists rue that more than the rampant drilling, it is the sheer thoughtlessness that is the more scary part. Citing an example from a village in Fatehgarh Sahib district, experts from the Punjab State Tubewell Corporation point out that a shallow tubewell with 20 m of tapped water-bearing zone could have achieved the purpose of drinking water supply. But the agencies drilled till 275 m and tapped 65 m of aquiferous zone to achieve their objective. “This is like using a cannon to kill a fly. Totally absurd,” says a geophysicist. According to a study conducted by a noted PAU agricultural economist, Dr Joginder Singh, as reported in media, only 3.12 million hectare-metre good quality water is available against a requirement of 4.90 million hectare-metre. The study further notes that the water table in the “sweet water” region of the state, which includes Ludhiana, Jalandhar, Kapurthala, Patiala and parts of Sangrur districts, fell at an average rate of 0.2 m per annum between 1979 and 1991. “The water table may go down to such an extent that lifting water to the surface would require heavy capital investment in the form of high-power electric motors or submersible pumps,” says the report. “In the Kandi area, deep tubewells have become a necessity because of non-availability of aquifers. Most of this area has a perched water table. Shallow tubewells dug to tap 15-20 m of water are not-sustainable because of the lensoid nature of aquifers,” says Prof. K.P. Singh, an eminent hydrogeologist who also has an Indo-Swedish project on Punjab groundwater to his credit. (Perched water table is a relatively small groundwater body lying above the general groundwater body.) White, grey & dark The National Environmental Engineering Research Institute (NEERI) has reported that nine Indian states (Punjab and Haryana included) are now running major water deficits. Similarly, a World Bank study warns, “Six of India’s 20 major river basins have less than 1,000 cubic m per year, with localised shortages endemic in all.” The problem is of a dangerous level in Punjab, and the 1 million tubewells in the state are only compounding it. Punjab, which is divided into 138 hydrogeological blocks, already has 61 per cent of them categorised as dark zones that are over-exploited. Out of the rest, 14 blocks (10 per cent of them) fall under the grey-zone category, where the groundwater exploitation is almost equivalent to the recharge. This leaves just 30 per cent of the area categorised in the white zone, where recharge is more than the exploitation. On the face of it, the scenario may not seem to be very alarming, but one has to keep in mind that most of the white zone is areas where water has never been exploited because of its brackish and non-potable nature (south-west Punjab and parts of the Kandi belt). Drilling a deep tubewell where a shallow one may do, faulty drilling, deep drilling by private drillers with a ‘vested’ interest, or drilling for the sake of getting more water — every excuse to drill a tubewell is contributing towards groundwater depletion. And if this water table drop continues at the current rate, soon we might well be adding a new item on our ration card — a drop of water. |
|
Avian influenza: scare of the foul fowls The causal organism is Orthomyxovirus Type A virus — virulent and avirulent strains of viruses with 14 known surface haemagglutinins infect avian species. However, recently the H5N1 strain of the disease is found to be associated with poultry as well as humans. Transmission The virus can be transmitted from infected to healthy birds by inhalation or by direct contact with nasal and oral discharge. WHO confirms that poultry-to-human transmission is also possible by direct contact. Those most prone are: persons associated with raw poultry meat; meat inspection/hatchery personnel; those suffering from human influenza or other respiratory infections; and veterinarians. The disease can also be transmitted by migrating water fowl, imported pet or other birds. Symptoms In poultry: The incubation period of the disease varies from a few days to one week or more. The signs in poultry include decline egg production or fertility along with respiratory signs. In some cases, infection in the brain also occurs. Severely affected birds have greenish diarrhoea, cyanosis and oedema of the head, comb and wattles along with ecchymotic haemorrhage on the shanks and feet. In respiratory signs, blood-tinged discharge is there from oral and nasal mucosa. Sinusitis may also occur. Because of the variation in the strains of virus, the and severity of gross lesions is also variable. It may consist of ecchymotic haemorrhage in the respiratory tract, gastrointestinal tract or urogenital tract. Death is also possible. In humans: Influenza symptoms are fatigue and fever along with respiratory signs such as conjunctivitis, sore throat and cough. There may also be muscle ache in some cases. The disease is more severe if a person is already infected with a human influenza virus. If left untreated, there may be respiratory distress and failure of kidney or haemorrhage in vital organs. Diagnosis The disease may be diagnosed from symptoms and clinical signs. It can also be detected by a haemagglutination test by the isolation of virus in embryonating eggs that agglutinate RBC of poultry. A gel precipitation test using known positive influenza A antiserum can also detect the disease. Treatment, control —Isolation of affected birds and culling and burning or burial of carcasses. —Vaccination of chicks with an oil-emulsion vaccine which contains 14 antigenically distinct haemagglutinatinin serotypes. However, this may not be successful because the virus continuously changes its surface antigens. —Use broad-spectrum antibiotics to control secondary bacterial infection. —Raise the temperature of the poultry house; it may help in reducing mortality. —Amantadine hydrochloride may be used both in poultry and humans but it is useful only at the initial stage, when the virus replicates by uncoating of viralnucleic acids. Prevention —Always cook the meat thoroughly above 70°C — that kills the virus effectively. —Boil eggs properly before eating. —Wash hands frequently while handling raw meat. |
|
Bird flu scare in North-East GUWAHATI: “How safe is your chicken?” is the question that is often being asked in the North-East with consumers already in a state of panic following bird flu in South-Asian countries, with which the region shares a 4000-km long border. More than anywhere in the country, the panic button is being pressed in this region due to its proximity to China, Myanmar, Bhutan and Bangladesh. Almost immediately after the deadly virus struck the neighbouring countries, consumers in the region, 90 per cent of whom are non-vegetarian, stopped purchasing poultry products, causing a whopping Rs 1 crore loss per day. Several governments in the region have sounded a health alert and stopped importing any poultry products from across the border even as experts within the region have made a passionate appeal that there was no such fear. Manipur,
Mizoram, Arunachal Pradesh and Assam have asked the Border Security Force to keep a close watch on the international border to foil any attempt to import poultry at cheaper prices.
— PTI |
||
|
Study casts doubts over Bt cotton benefits...
THERE is some bad news for Indian farmers who have started growing a type of genetically modified cotton containing the Bacillus thuringiensis (Bt) gene. The Bt gene produces a toxin called “Cry1Ac” that kills bollworm—the biggest enemy of cotton. But a study just released by entomologists at the Indian Agricultural Research Institute in New Delhi has cast doubts on the long-term benefits of Bt cotton. It has found that the protection afforded by Bt gene is at best for six years. The study by K. Chandrasekar and G.T.Gujar has found that bollworm develops “31-fold resistance to the toxin Cry1Ac within six generations.” Bollworm also developed cross-resistance to two more toxins called Cry1Aa and Cry1Ab. Cotton farmers in the country spend Rs1200 crore on pesticides to protect their crops from this single pest. What this study means is that they may have to go back to spraying pesticides after six seasons unless scientists come out with Bt cotton hybrids that produce a higher dose of the Cry1Ac toxin. The scientists say their findings “mandate the necessity of Bt resistance management.” One way of doing this is by ensuring that each farmer allots a part of his land for non-Bt crops—a requirement unlikely to be followed by farmers with small land holdings. The development of resistance to Bt cotton is not unknown. In China, the expected life of Bt cotton was found to be seven to 10 years in areas under Bt cotton exceeding 70 per cent. — PTI |
THE recent spurt in the shifting from shallow to deep tubewells by farmers of the region may have been caused by the greed for more water in the eighties, which virtually dried up the upper layer of earth. 
AVIAN influenza is an acute disease of poultry characterised by a decline in egg production along with lesions in brain. However, its respiratory signs are more common. The disease has zoonotic importance as it has also spread to humans in South-East Asia.