Go green with plastics
Plastic is labeled as environmentally harmful but it has many advantages in agriculture, describes Ashok K Gupta

Plastic products in the form of films, sheets, tubings, nets, moulded products and in many other forms are deployed in plasticulture applications. Plastics applications which are being used commercially, playing a significant role in agriculture and allied sectors are nursery bags, pots, baskets, pond & reservoir lining, drip & sprinkler irrigation systems, plastic mulching, greenhouse, plastic tunnel, shadenet house, bird nets, insect proof nets, fencing nets, trays, boxes, crates, flexible bags etc.

Plastics applications offer a multitude of benefits and are considered the most important indirect agricultural input, which result in moisture conservation, water saving, reduction in fertiliser consumption, helps in concise application of water and nutrients. It has been widely accepted that environmentally-controlled agriculture is economically viable. Plant protection through the use of nets and innovative packaging solutions helps in increasing shelf-life during collection, storage and transportation of fruits vegetables.

PLASTIC IN NURSERY
To produce quality seedlings, grafts and plants, plastic bags, pots, plug trays, sprayers, seed trays, pro-trays and hanging baskets are used. These applications help in easy handling and during transportation.

POND/ RESERVOIR LINING
Plastic film lining has proved to be effective against seepage in canals, ponds and reservoirs. Pond lining has been effective in avoiding depletion of stored water used for drinking and irrigation purpose. It is an effective and economic method to harvest rain water and store it for supplementary irrigation, fisheries, livestock and domestic purposes. It provides several advantages like:

• Prevents soil erosion
  
• Highly useful in porous soil, where water retention in ponds and water harvesting tanks is low.
  
• Lining of plastic film in ponds, canals and reservoirs improves water availability for a longer time, thus reducing seepage.
  
• Eliminates water logging and prevents upward intrusion of salts into stored water.

DRIP IRRIGATION SYSTEM
Drip irrigation system helps in ‘precise and regulated application of water along with plant nutrients at low pressure and frequent intervals, with a close network of pipe through drippers/ emitters directly into the root zone of the plant’ that helps in water saving and enhance crop productivity. In India, presently more than 21 lakh ha area is under the drip irrigation system. It has several advantages, which include:

• Water saving by 40-70 per cent
  
• Improves quality, quantity and allows early maturity of produce
  
• Controls weed growth, saves fertiliser up to 30 per cent and labour cost by 10 per cent, as compared to the conventional method
  
• Reduces soil erosion
  
• Controls diseases
  
• Prolongs crop maturity duration

SPRINKLER IRRIGATION SYSTEM
Sprinkler irrigation system allows application of water under high pressure with the help of a pump. It releases water similar to the rainfall through a small diameter nozzles placed in the pipes. This system is adopted in all types of irrigable soil due to wide range of discharge capacity. The advantages of this system include:

• Water savings up to 30-50 per cent
  
• Reduction in soil erosion
  
• No compaction of soil
  
• Land leveling is not required
  
• Level frost protection
  
• Provides cooling of crops as water is sprayed over the crops
  
• Reduces labour cost
  
• Alteration of micro climate
  
• Penetration of fertiliser into the soil can be regulated by time of application

PLASTIC MULCHING
Covering the soil around the plant with plastic film to conserve soil moisture, prevent weeds and modify soil temperature is called mulching. This method is predominant in large-scale vegetable growing, with millions of acres cultivated under plastic mulch worldwide each year. Disposal of plastic mulch is cited as an environmental problem; however, technologies exist to provide for the recycling of used/ disposed plastic mulch into viable plastic resins for re-use in the plastics manufacturing industry. It has the following advantages:

• Reduces evapo-transpiration, thereby maintaining optimum soil moisture and temperature for plant growth
  
• Prevents weed growth and increases availability of soil nutrients for the plant
  
• Reduces frequent irrigation
  
• Provides ideal environment for soil organisms
  
• Prevents soil erosion and run off
  
• Reduces soil compacting due to heavy rain

GREEN HOUSE
Green houses are frames or inflated structures covered with a transparent/ translucent plastic material, in which crops can be grown under controlled or partially controlled environment. The greenhouse technology has been of considerable importance in better space utilisation, growing crops in extreme climatic conditions and high rainfall areas. Its advantages include the following:

• Provides favourable climatic condition for plants
  
• Higher yield with better quality
  
• Reduces cost of production
  
• Controls pest and diseases
  
• Intensive farming of high value crops
  
• Helps hardening of tissue cultured plants.

PLASTIC TUNNEL
Plastic tunnels are miniature structures producing greenhouse-like effect. These tunnels facilitate the entrapment of carbon dioxide, thereby enhancing the photosynthetic activity of the plants and hence the yield. These structures also protect the plants from high winds, rain and snow. Besides these are less expensive, easy to construct and dismantle. It has several advantages like:

• Provides favourable condition for better nutrient uptake by the plants
  
• Provides microclimate for seedlings and grafts
  

PLANT PROTECTION NETS
Plant protection nets are used to protect vegetable and fruit crops against solar radiation, insects, birds, hail, wind, snow or heavy rainfall.

SHADENET HOUSES
Shadenet houses come in different shade factor and density, ranging from 35 to 90 per cent. Presently shadenets are available in white, black, red, blue, yellow and green colours. These is used in nursery, green house, terrace garden and fencing. Specific nets are used as a remedial action to protect the plant and fruits from insects, birds, animals and extreme weather conditions. Depending upon the use, these nets are available in different mesh size or strength to withstand weather conditions. Their use has the following main advantages:

• Used in cultivation of flowers, foliage & medicinal plants, vegetables and spices
  
• Used for growing off-season vegetables
  
• Helps to enhance yield during summer season

SUB-SURFACE DRAINAGE
Sub-surface drainage is a method of draining excess water from the root zone of the plants, either naturally or by artificial means, such as using a network of pipes below the ground surface. Sub-surface drainage is designed at a lower water table level that allows optimum root development. It prevents capillary movement of salts into the root zone of the plant. It has many advantages, which include the following:

• Designed to remove excess water from soil to prevent water logging
  
• Regulates water table and ground water flows
  
• Most effective measure to control soil salinity
  
• Reclaims and conserves agricultural land to optimise crop yield
  
• Improves soil environment for vegetable growth, water quality and reduce erosion
  
• Decreases the amount of surface run off, thus reducing loss of nutrients generally caused due to runoff

INNOVATIVE PACKAGING SOLUTIONS
Packaging is one of the most critical areas in the distribution and marketing of agricultural produce. Over the years, the concept of packaging has evolved from that of serving as a mere container to sophisticated package incorporating sales appeal, convenience, long-term protection, portability, shelf-life and cost-effectiveness etc. Traditional packaging using materials such as wooden crates and gunny bags have many disadvantages. The properties of plastics such as flexibility, light weight, hygiene, safety and transparency provide invaluable contribution for the processing, storing, preserving and transporting of produces.

Innovative packaging products are used with many advantages. More than 30 per cent of agricultural produce is lost between the farm and consumer. The packaging must stand up to long distance transportation, climate, storage condition and multiple handling during distribution and marketing. In designing a good packaging solution, one must consider physiological characteristics of the produce and its distribution network. Therefore, plastics play a very important role in transportation of fruits & vegetables from one place to another.
— Ashok K Gupta is Director, Diplast Plastics Ltd

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