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| AGRICULTURE TRIBUNE | Monday, June 30, 2003, Chandigarh, India |
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A hazard
going unnoticed Green-manuring
is cost effective
Lantana: As noxious as it is beautiful HP warms to wool |
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A hazard going unnoticed The management of biomedical waste is still in its infancy all over the world. There is a lot of confusion among the generators, operators, decision makers and the general community about the safe management of biomedical waste. Biomedical waste is generated from agriculture and food-processing industry, healthcare establishments such as blood banks, laboratories and research institutes, veterinary hospitals, abattoirs, etc. Standards for deep burial of waste Biomedical waste management is a special case wherein the hazards and risks exist not just for the generators and operators but also the general community. Hazardous waste may cause damage due to inadequate storage, transportation, treatment, or disposal operations. Improper waste storage or disposal contaminates surface and groundwater supplies. Moreover, improper disposal of municipal solid waste can create unsanitary conditions. The task of collecting, treating and disposing of solid waste presents complex technical challenges. Agro and food-processing industries are considered the largest contributors to the total production of solid wastes. Animal industries too generate a wide variety of by-products and wastes—generated by abattoirs, butcheries, poultry processing industries, dairies, hatcheries and animal farms.
Waste can be valuable Animal waste seems to be valueless at first instance, but it can be utilised as a valuable product after processing. Livestock waste can be characterised as high strength, low volume waste in contrast to municipal waste, which is low strength and high volume. Animal waste can occur as solids, semisolids or liquids, depending upon the design and operation of the product unit. Waste from ruminants has a different composition than that from mono-gastric animals and poultry. Waste needs to be handled and disposed of scientifically to prevent any outbreak of disease or poisoning in animals as well as human beings. In India, animal waste is generally disposed of with least regard for public health and hygiene. It is commonly seen that carcasses are left on roadsides for municipal garbage lifters to remove. Even animal excreta and other wastes are disposed of on the streets, creating public nuisance and health hazards. Different categories of animal waste need different treatment and handling for disposal. Slaughter houses: Animals slaughtered for meat produce disposable waste like skin, viscera, stomach content, blood, wool, body fluids, hooves, teeth, bones, etc. Except the skin, most of these by-products are not utilised in this part of the country. These need to be disposed of scientifically to prevent contamination and spread of disease. Since there is an absence of modern slaughterhouses in India, butchers must be made responsible for the scientific disposal of the waste products at predetermined spots. Municipal authorities should have facilities for incineration of the waste. In the villages, panchayats may take similar steps for disposal in a burial ground located far from human habitation and livestock farms. These burial grounds should be high barren lands. It must also be ensured that animals do not have access to the burial sites. Though not many meat-processing units are in operation in this region, it is necessary to incinerate rejected meat in mini incinerators located on the premises. Fluid and chemical wastes should be disinfected and released into the drainage system. Utilising animal by-products can add to the income from the meat industry. If these by-products are not effectively utilised, a valuable source of potential revenue is wasted; also, the added cost of disposal of these products is incurred by the industry. Here lies the urgent need for the establishment of organised meat-processing plants in the region. Livestock and poultry:
Livestock and poultry farms are major producers of waste. Dung and urine can be used for the production of biogas for domestic use and the residue is a good bio-fertiliser. Poultry litter mixed with loamy soil also makes good fertiliser and can be used in agriculture. Farms:
Other farm waste like dead foetuses, placenta, dead birds, etc., should be buried deep. Waste feed and fodder should be dumped in pits on farms, to be used later as manure. The milk from diseased cows suffering from mastitis should be disinfected properly with chemicals and released into the drainage system. Milk plants:
Milk plants produce a lot of by-products like whey, curdled milk and used polythene pouches. These need to be disposed of properly to prevent contamination of the plant itself. Since milk and milk products are a good medium for microbial growth, waste materials should be immediately disinfected chemically and released into the drainage system. Used polythene pouches should be autoclaved and shredded for disposal. Veterinary institutions involved in routine pathological work and production of vaccines produce microbiological and biotechnological wastes. These are highly infectious and hazardous for both animals and humans. They need to be autoclaved, microwaved or incinerated as per requirement. Laboratory animals like mice, rabbits and guinea pigs after death must be incinerated or buried deep as per standard norms.
Enforcing rules According to the WHO, the responsibilities of hospital and healthcare establishments include proper disposal of solid, liquid and other aqueous wastes. Waste products like animal tissues, organs, body parts and fluids, blood, experimental animals used in research, veterinary hospital waste, discharge from animals houses, etc., are supposed to be incinerated or buried. All disposables should be chemically disinfected prior to disposal. There should be strict measures for proper implementation of the Biomedical Waste (Management and Handling) Rules, 1998, of the Ministry of Environment and Forests. Adequately trained and empowered inspectors should be appointed for successful implementation of the rules. |
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Green-manuring is cost effective Chemical fertilisers only provide one or two major nutrients, while the soils are becoming deficient in micro-nutrients. Our efforts should be on gradual reduction of chemical use while sustaining productivity. An important way is the use of bulky organic manures, which can improve the organic content of soil, thereby enhancing its physical, chemical and biological properties. Organic manures improve the nutrient balance. Bulky organic manures can be supplied through farmyard manure, farm compost, town compost, night soil, sludge, green manure, etc. Out of these sources only farmyard manure and green manure are widely used. Farmyard manure is prepared from dung, yet about 60 to 70 per cent of dung is used as fuel in rural areas. Also, the dung is not managed properly and the quality of manure is not good. Thus one practical way left for supplying organic matter is green-manuring. Green-manuring is ploughing into soil live plant material for improving the physical structure as well as fertility of the soil. This practice is feasible in the rice-wheat cropping system, because a green manure crop requires large quantities of water for decomposition. Green-manuring can be done in two ways depending on the situation. (1) Green-manuring in situ: this is the growing and burying of a green manure crop in the same field as the one to be manured. (2) Green-leaf manuring: this is turning into soil green material like leaves and twigs collected from shrubs and trees grown on bundhs, wastelands or nearby forest areas. Depending on the conditions, farmers can follow either of the two methods. This practice adds organic matter to the soil, improves the physical properties of soil in terms of aeration, porosity, water-holding capacity, and facilitates penetration of rainwater. Green-manure crops hold plant nutrients that would otherwise be lost by leaching. Leguminous green-manure crops add nitrogen to the soil. This practice increases the availability of nutrients like phosphorus, calcium, potassium, magnesium and iron. In the rice-wheat cropping system the use of chemical fertilisers can be reduced by one-third if green-manuring is done before the rice crop. Researchers have documented that there is no need of applying phosphate fertilisers in the rice crop if the same dose is applied in the green-manure crop. This enhances the growth of the green-manure crop, thereby giving more quantity of organic matter. While green-manuring one has to keep in consideration that there should be sufficient water available for decomposition of the green-manure crop. The practice is economical if the green-manure crop is taken between two consecutive crops. In Punjab and Haryana, wheat is harvested in April and rice is transplanted in June. The fields thus remain vacant for about two months, which can be utilised for green-manuring. Scientists have developed a package of practices for this. The green manure crop dhaincha (Sesbaina aculeata) should be sown in the second half of April using 10 kg of seed per acre. The dose of phosphate fertilisers meant for the rice crop should be applied in dhaincha at the time of sowing. This green-manure crop should be ploughed into the field at 6-7 weeks of age. The transplanting of rice seedlings can be done easily after a week. |
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Fighting
lantana the weed Lantana, according to Encyclopaedia Britannica, is a genus of more than 150 shrubs native to tropical America and Africa and belonging to the verbena family. Common lantana growing up to 10 ft tall is a weed in tropical America. But elsewhere it is also much used as a garden plant. It blooms almost continuously with yellow, orange, pink and white flowers in various colour combinations. Its aromatic leaves are rough and oval. Clusters of poisonous black berries follow the flowers. Lantana is a serious threat as a weed on account of upsetting the bio-diversity of an area. The UT Administration on June 5, 2003, launched a 'war' against lantana, declaring it a 'deadly weed' in the forest areas of Chandigarh and in the Sukhna Wild Life Sanctuary. In the fight the mode adopted is manual removal of the weed and its destruction or disposal by burning. The task is expected to be completed in next three years. Lantana is causing the 'slow death' of many tree species like khair, dhak etc., as it covers the trees, retarding their growth. Lantana is also pushing a wide variety of endemic medicinal herbs, shrubs and babbar grass into extinction and this results in greater soil erosion as the grass acts as a soil binder. In addition to the 'manual' mode, two other methods available are chemical sprays, or weedicides, and biological control.
Biological control Though the effort to control weeds biologically is a recent development, in the case of lantana trials were made as far back as 1902. It was decided to import insects from Mexico to Hawaii to control lantana, which was spreading over thousands of acres of pastoral land. Work has continued since then and additional insects species have been added from time to time. Slowly but surely lantana has been found to be yielding to the insect attack and control is said to have been established. Attention was focussed on lace bugs and seed-destroying flies. Mycoherbicide: Lantana camara has become one of the most notorious weeds and a number of countries have reported about this thicket-forming woody shrub as a serious weed. The weed is poisonous to livestock and has infested millions of acres of natural grazing land. In India it has been responsible for many 'forced relocation' of villages. A research centre has been established at the Imperial College, London, where work is being carried out to assess the potential of mycoherbicides (fungi that kill living things) for bio-control of several tropical weeds, including Lantana camara. This centre has evolved P. Lantana CABI isolate No. 1914, which holds potential as a classical biological control agent in the exotic range of its host. This pathogen has been found to hold greater potential than first thought. Using this mycoherbicide infections were established in Lantana camara, with the first symptoms occurring in 5 to 9 days after inoculation, and sporulation taking place after 11 to 15 days of inoculation. Infection occurred mainly on the leaves and stems and the pathogen grew systemically in the Lantana camara biotype from India. This systemic growth within the host suggests that the pathogen can secure longer-term survival and the ability to form a reservoir of infection and inoculation within the population. Pathogenicity tests carried out indicated a potentially wide application of the pathogen as a mycoherbicide for the lantana biotype from India. In addition, the host specificity of pathogen bode well for its status as an environment-friendly bio-control agent, since none of the other test plants related to Lantana camara exhibited a compatible reaction with rust. In Australia, the first pathogen agent has been released at two locations: The Tamborime mountains located in the southeast of Queensland and Mount Warning in northern New South Wales. The results are encouraging. The rust fungus released was obtained after five years' research by bio-control organisation CABI Bioscience in Ascot and a Brazilian organisation, Universidade Federal de Vicosa. But it must be kept in mind that it would require 10 years for the rust to control the weed. Biological control is more desirable as compared to chemical control in view of time-ecological effects, but biological weed control has some definite limitations as mentioned above. |
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HP warms to wool Sheep rearing is one of the main vocations of most of the farmers in Himachal. About 37 per cent of agricultural families are engaged in this. Most of them live in snowbound and tribal areas. The total sheep population of the state is about 11 lakh. Rampur Bushari and Gaddi breeds have been popular till now, but their wool yield is as low as 1 kg per sheep per year as compared to 2.5 kg, that also of good quality wool, from cross-bred sheep. To improve the quality and quantity of the wool in the state, the state government is arranging to cross local ewes with good quality rams, which are being supplied from departmental farms at Karcham in Kinnaur district, Jeori in Shimla, and Tal in Hamirpur district and from Chamba. Besides, one ram centre has been established at Nagwain in Mandi district, from where rams are supplied to breeders during the breeding season, after which they are brought back to the centre. Ten sheep and wool extension centres at Choori, Lunapur, Bharmour (Chamba), Kothikohar (Kangra), Bagipul (Kulu), Lari, Udaipur (Lahaul and Spiti), Dodrakwar (Shimla), Swar (Mandi), and Sangla (Kinnaur) are also supplying rams for breeding. An intensive sheep development project is being implemented in the Bharmour area. To ensure production of quality wool, analysis laboratories have been set up at Tal in Hamirpur, Jeori in Shimla and Sarol in Chamba district. Angora rabbit breeding has been given priority, as it is a good source of income. An Angora rabbit farm was initially established at Nagwain. Later, another was opened at Palampur, where German Angora rabbits were reared, which produce more than 1 kg of wool per rabbit per year as compared to 400 gm from earlier breeds. With the assistance of the UNDP, a germplasm centre has been established at Nagwain in Mandi district, where pure lines are being bred and trained persons are being provided infrastructure and rabbits for propagation. The state wool federation is implementing various schemes sanctioned by the Central Wool Development Division, Jodhpur. Under this project, more than 1,25,000 sheep in Kangra and Chamba districts have been covered. |
* Dig a pit or trench about 2m deep. Fill it half with waste, and then cover it with a layer of lime, before filling the rest of the pit with soil.
In agriculture, organic matter is considered the backbone of cultivated soils. In the early 1970s the organic matter in the soil was around 0.7 per cent, which has now declined to 0.2 to 0.3 per cent, particularly in the intensive crop cultivation region like northern India. The continuous use of fertilisers and pesticides has altered the biological properties of soil. Microbial activity in soil has decreased. Soil aeration, porosity and water-holding capacity have been affected due to the reduced organic matter.