Due to increasing population and demand for food grains, declining water resources, increasing cost of inputs, machinery, energy, increasing desertification and deteriorating soil and environments
, a new approach known as the conservation agriculture is gaining ground in the world.
The green revolution model which requires high inputs and expensive technology, could not lead to the sustainable betterment of small and resource poor farmers of the developing world. In other words, it has failed to reduce poverty in the third world and it also faces environment crisis such as increased soil erosion, salinization, pesticide pollution, desertification, loss of bio-diversity and natural resource base.
However, the conservation agriculture seeks to conserve, improve and make more efficient use of natural resources through integrated management of the available soil, water crop and other biological resources in combination with selected external inputs.
It represents a resource-saving and effective agriculture which contributes to environmental conservation and at the same time enhances sustainable production. Its key features are:
No ploughing, disking or soil cultivation (i,e no turning over of soil);it provides a method of soil moisture conservation and saving irrigation; it ensures that there is less run-off of valuable water and more water infilteration compared to the more traditional methods; it ensures crop and cover crop residue stay on the surface crop rotations and cover crops are used to maximize biological control; no burning of crop residues; permanent crop and weed residue mulch protects soil erosion; it helps restore soil organic matter; increases soil microbes that are useful in the biological control of soil born pathogens; it also increases yield because of timely planting, effects on soil structure, water and biological factors; decreases energy and labour costs for farmers resulting in higher profits; it uses specialized equipment; enables continuous crop-land use.
These are just some of the key features of conservation agriculture which may be used according to the requirements of a site specific and socio-economic conditions of farmers.
For instance, it was practised on 45 million hectares in 1996-97 mostly in the USA, Canada, Brazil, Argentina, Mexico, Paraguay, Australia, etc, but now it has spread to over 72 million hectares in 50 countries including China and those in South East Asia.
Conservation agriculture is now applicable to all crops, soil and environmental conditions and encompasses a wide range of agro-ecological zones, from north to south and lowland to hilly lands and highlands; farm sizes and cropping systems from subsistence, hand-hoe based small farms to large broad acre fully mechanized farms in Australia and USA and under both rain-fed and irrigated conditions.
The FAO has also been promoting conservation agriculture for over a decade, particularly in Latin America. As conservation agriculture is becoming a great success story for increasing food security and reducing poverty in this continent, the FAO has officially adopted this concept as one of its major activities and as a result is expanding this programme to Africa, Central and South East Asia. Some of the conservation agriculture also known as conservation tillage. The conditions obtaining in Pakistan are discussed as under:
SURFACE SEEDING: It is the simplest system for wheat but can also be used for other crops including rice. The seeds are broadcast onto the saturated soil without any tillage operation.
This is the only system for low lying poorly drained heavy rice soils that don't allow timely tillage operation for sowing wheat and thus remain fallow in the winter season as in Nepal.
This practice cuts the cost of production by more than a third and requires no implements. Due to these advantages even the resource poor farmers are now increasingly using it in Nepal and Bangladesh.
This method has a good potential for small, subsistent and below subsistent-level farmers. However, sowing on the open soil surface makes it possible for seed to be damaged/eaten by birds. To protect the seed from bird damage it is essential to prepare a thin layer of cowdung on seed surface before seeding.
BED-PLANTING: This system is used in many countries for wheat, rice and other crops. Beds are formed every crop season. The configuration is variable, but in South Asian rice wheat areas, two beds are formed to fit between the two tractor wheels.
Each bed is about 70cm wide and 1 to 3 rows are planted on top of beds depending on the crop. Similarly permanent bed systems are used for a number of crops. This reduces the cost of bed formation and is essentially zero or reduced tillage on beds.
RICE PLANTING: Rice is generally grown as a puddled and transplanted crop to reduce water percolation losses and weed infestation. Paucity of labour in peak rice transplant season, increasing transplanting and puddling costs and inadequate population planted per unit area by the hired labour has necessitated the need for alternate methods for establishing rice crops direct seeding of rice is one of the options, where rice seed can be seeded directly into moist soil using drills or else pre-soaked, pre-germinated seed is broadcast into the puddled soils.
Direct seeded rice has the advantage of faster and easier planting, less labour and drudgery and earlier crop maturity by more than 10 days as compared to transplanted rice. Again, Chinese have developed a parachute rice planting technology in which seedlings are raised in plastic bubble sheets and then blown high in the air to make them land upright in the puddle fields.
This method saves labour and is quick and cost effective. Some other methods like dry seeding of rice as in other crops, bed-planting of rice by transplanting or dry seeding on the top or sides of the bed and seeding on moist soil like zero-till wheat, are also used according to the situation,
REDUCED TILLAGE: Chinese made 12 horse-power two-wheel diesel tractor that prepares the soil and plants in one operation (reduced tillage). It allows timely sowing of wheat after rice even in poorly drained low-lying areas and still lowers the cost of cultivation by one-third and increases yield by one-fourth.
It can command 12 hectares of land and can be locally repaired. This tractor is now being increasingly used by farmers especially small farmers in Nepal, Bangla Desh and Indo-Gangetic Plains.
It has great potential of timely sowing of wheat in the rice-wheat belt and thus increasing production of wheat, The policy makers should seriously consider to introduce this technology at the earliest.
ZERO TILLAGE: This technology consists of a Newland madezero-till seed drill driven by a four wheel tractor but its high cost was one of the limiting factor for its use. However, due to the efforts of Directorate of On Farm Water Management, Lahore, and Agricultural Department, Ludhiana (India).
This drill was locally made at cheaper rates in their respective countries. It places both seed and fertilizer directly into the soil in standing rice stubbles without prior tillage.
It saves cost of cultivation upto Rs2000 in Pakistani Punjab and Rs3000 even after paying rent of hired tractor in Haryana State of India. It saved water up to 20 per cent, reduced cost of diesel and increased yield per hectare by 15-20 per cent.
HAPPY SEEDER: The burning of rice stubbles in several rice growing areas of the world to aid in the seed bed preparation for the subsequent crops causes two major problems.
First it causes environmental pollution problem affecting human health in the rice growing areas and secondly it causes reduction in soil organic matter due to burning of rice stubbles which is a threat to long term soil health.
The happy seeder approach enables direct drilling into heavy stubble and trash in wet or dry conditions by simultaneously removing the stubble/trash and direct drilling into bare soil.
It is able to sow a field immediately the harvester has passed, thus providing an option for timely sowing and using soil moisture before it evaporates. It saves many passes with tillage implements a common practice on the sub-continent, even after burning of stubbles.
This technology reduces the risk of wind and water erosion, improves soil organic matter content, structure and infiltration, and reduces evaporation from the soil surface thus potentially improving water use efficiency.
PLASTIC COVERING: In order to make full use of water in water deficit hilly areas of northern China, its agronomists have invented a plastic covering sheet for conservation agriculture.
This technique significantly increased their water use efficiency on their hilly lands where only one crop a year could be taken, now two or three crops are taken in a year.
The main points of this technique are, applying fertilizer as basal, making raised bed and covering plastic sheet on bed, planting wheat on furrows in the fall; and planting summer crops such as sweet potato, tobacco, peanuts or maize in early summer of coming year.
HYDRO-TURBINE: The Indus plain have several mighty rivers and small perennial streams and drains that flow throughout the year If flow energy of water in these streams and rivulets is harnessed by using the Chinese hydra-ramp turbines it may not only produce five kw of hydra-power but lift water over 30 metre height on the side of a stream bank having a cultivable area at 60-70 liters per second.
Installation of such pumps on seasonal steams may also help to lift and store water in the storage ponds during monsoon season and use it as supplemental irrigation to rain-fed crops during post monsoon season to increase yields of rain-fed crops. This technology is fast spreading in South Asian countries including the Indo-Gangetic plains.
These are just some of the conservation agriculture technologies used worldwide and have great potential to conserve our declining resource base and increase production of food grains to meet the increasing food requirements of our burgeoning population The policy makers should develop a comprehensive programme of developing conservation agriculture in Pakistan with the assistance of the FAO as it has already become its part of development programmes.
