Need for Promoting Use of Plastics in Horticulture

Introduction:

The advances in technological developments have modified so much the course of controlled

environment, horticulture in the production of fruits, vegetables, flowers, and ornamentals due to the

recent widespread use of plastic films and related materials in horticulture production. The plastic films are used extensively for the design and covering of new greenhouses; the covering of old conventional glass-greenhouses; for air-inflated, self-contained, or supported bubble houses; as interior curtains and external barriers to reduce heat loss in the conventional greenhouses; and for the containment of CO2 -enriched atmospheres. The plastic films also are used in the construction of high and low tunnels or covers for many row crops, protective covering of seed beds, and for soil mulches. Plastic tubes, laterals, and drip lines are important components of drip irrigation systems for high-value horticultural crop production. Drip irrigation is often a component with plastic soil mulches, crop rowcovers, and plastic greenhouses. Recent introductions using plastic films include peat modules, bag cultures, rockwool, the nutrient-film technique, and non-variable root environments for fieldgrown tomatoes. Plastic components contribute to the precise control of top and root environments of the crop plants. In many modern greenhouses, all plant growing structures, other than the root media itself are plastic.

Benefits of plastics:

The use of plastics has proved beneficial to promote the judicious utilization of important natural resources like soil, water, sunlight and temperature. Use of plastics in agriculture or ‘Plasticulture’ provides several benefits like;

• Effective control on pest and disease infestations

• Improves the economic efficiency of production

systems

• User friendly maintenance

• Efficient water and energy management

• Reduced temperature fluctuations

• Reduced moisture fluctuations

• Precise irrigation and nutrient applications and

reduced wastage

• Reduction in soil erosion

Use of plasticulture in micro irrigation:

Micro Irrigation One of the major sectors of application of plastics in horticulture is in the area of water management and conservation. The drip or micro irrigation includes emitting water by drippers, microsprinklers, mini-sprinklers, micro-jets, misters, fan jets, micro-sprayers foggers, emitting pipes, micro-tubes and similar other emitting pipes. Micro irrigation Technology can be used both on the surface as well as sub-surface areas which helps in increasing productivity by 30 to 100 percent with 50 to 70 percent saving of water. There is enhanced water use efficiency (WUE). Micro irrigation saves the energy as compared to sprinkler and conventional methods. Sprinkler irrigation enables water to be sprinkled with the help of a network of pipes and sprinklers (nozzles) on the plant foliage. Sprinkler irrigation system has become popular as a method of irrigation, especially under undulating topography, particularly for light textured soils for a variety of horticultural crops. The fertilizer use efficiency can also be enhanced when it is applied through drip irrigation. Increased productivity with saving of 30 to 40 per cent of fertilizer can be achieved through fertigation.

Initially, the central government launched a scheme on use of plastics in agriculture during the 8th plan, duly earmarking 200 crore for drip irrigation. The scheme was continued during the 9th plan under the title "Development of Horticulture" through Plasticulture Applications with an outlay of INR. 375 crore out of which INR. 300 crore was for drip irrigation. During 2003, the central government constituted a Task Force on Micro Irrigation to assess the scope and potential of the technology and to suggest strategies for its promotion in the country. The Task Force gave several recommendations for promoting Micro- irrigation in the country. Based on the recommendations of the Task Force on Micro irrigation several initiatives have been taken up by the central and state governments which has resulted in brining of lot of area under micro irrigation. The plasticulture programme, which started as a subsidy scheme is now a demand driven program in Karnataka and other states like Maharashtra, Telangana, Andhra Pradesh and Tamil Nadu. As a result of all these efforts, India has now emerged as one of the leading countries in using micro irrigation technology and plasticulture.

Plasticulture for popularizing Fertigation:

Fertigation need to be popularized for intensive and economical crop production, where both water and nutrients are supplied to growing crops through micro irrigation system. Fertigation provides major and micro nutrients directly to the active root zone, thus minimising losses of expensive nutrients, which ultimately helps in improving productivity and quality of farm produce apart from savings in the time and labour. Research studies have shown that fertigation economizes use of fertilizer and water to the tune of 40-60 percent. Farmers are using fertigation in grapes, pomegranate and banana crops in Karnataka and of late are being followed by small and resource poor farmers due to some schemes of Government of Karnataka. Fertigation is ideally suited for hi-tech horticultural production. Though micro irrigation has found widespread use in plantation and horticultural crop production, fertigation is confined to few high value crops.

Plasticulture in promoting protected cultivation:

Optimum growth of plants is governed by the availability and use of soil, water and sunlight. However, climatic variations often tend to have adverse effects on the yield and production of crops. There is a need to focus our efforts on harnessing the natural resources through artificial means for increasing crop productivity. One such technology is protected cultivation or green house cultivation. Greenhouses are framed or inflated structures covered with plastic material or glass in which crops can be grown under partially controlled environment which is large enough to permit normal cultural operation manually. Large greenhouses are usually constructed for export oriented flower production. Greenhouse technology was well adapted in Europe and USA by the end of the nineteenth century. Currently, China and Japan are the leading countries. Other countries where green house technology is being widely used are Netherlands, Israel, Canada, Spain and Egypt besides some Arab countries. Green house technology is currently catching up in India also. Green houses are suitable for growing a variety of vegetables, fruits and flowers. In addition to temperature control, there will be protection from wind, soil warming and in some cases, protection against insects, pest and diseases, thus helping in enhanced maturity of crop, increased yields, improved quality of produce and in some instances it can reduce the use of insecticides and pesticides. The total time for preparation of seedlings and cuttings also gets reduced significantly by the use of green house technology. Greenhouse is also essential for plant propagation through tissue culture. Considering the advantages of greenhouse, there is ample scope for encouraging area under protected cultivation of high value flowers and vegetables out of season, both in the temperate and tropical climate. However, profitability in green house cultivation will depend upon the choice of greenhouse structure, selection of crops and varieties and production technologies adopted. While the conventional greenhouses are simple structures, the hitech greenhouses have facilities for controlling light intensity, temperature, humidity with complete automation of the system. The constraint in adoption of green house is mainly the high investment required on equipments.

Indian horticulture, which was hitherto an individual activity, became corporate driven, which could

sense the potential and scope the modern protected cultivation technology. Refinement in protected

cultivation technology is being carried out in different ICAR institutions, state horticulture and agricultural universities. Different designs of glasshouse and polyhouses are being developed. Besides above-ground greenhouses, underground green houses were also being tried. Polytunnels and poly crop cover has also been tried.

Plasticulture in Mulching:

Plastics are popularly used for mulching in horticultural production. Mulching has been helpful not only in preventing moisture loss through evaporation from the and lowering the temperature, but also in reducing nutrient losses by leaching and weed control where chemical fertilizers and weedicides are used. Mulching also reduces run-off, increase penetration of rainwater, controls erosion, corrects the chemical balance of the soil and reduces damage done by pests and diseases. Soil moisture could be conserved through mulching either with black polyethylene or locally available mulches, growing cover crops or inter-culturing in the orchards to check soil erosion and runoff of rain water.

Plasticulture in promotion of sub-surface drainage system:

Sub-surface drainage is a proven technology in reclaiming saline and water logged land and restoring

the productivity of the land to its full potential. The subsurface drainage is designed to lower the water table to a level, which allows optimum root development and prevents the capillary movement of salts into the root zone. The basic principle of sub-soil drainage is that a set of corrugated/perforated PVC pipes is laid in a systematic order to collect excess from the water logged

soil. The water so collected is led into a collector pipe system, which in turn drains into the main drains. Some of the advantages of sub surface drainage systems are: (a) useful in removing soil salinity and reducing water logging (ii) helps to control run-off and flood waters (iii) It requires less maintenance and long life and most reliable system. This technology needs to be promoted in the areas covered under horticultural crops which are affected by soil salinity and water logging.

Way Forward:

Though the use of plastics in Indian horticulture was late compared to different countries of the world, its promotion should be top on the priority programmes of the both central and state governments. The plasticulture based technologies can help the farmers in better utilization of resources in different geographical locations for production of good quality horticulture produce which can fetch better prices for the farmers. It also opens up avenues in export of quality produce

and processing sectors. The different programmes on use of plastics should be promoted more rigorously. The research institutions need to pay more emphasis on use of plastics in horticulture production.