Nature is dynamic. It causes inheritable changes in all living organisms. For thousands of years, farmer around the world have been selecting and conserving varieties of different crop plants that they cultivated. This process has generated a rich wealth of varieties in each crop plant, seen to be most abundant in countries near the equator and India is no exception. In the world there are Mega centers of biodiversity of which aware present in India. This is because in India, the different soils and agro-climatic situations are present. So Indian farmers grow a large number of crops. Generation of Indian farmers, with their continued selection and conservation, has created a rich wealth of varieties in many crops. Therefore India is the original home of many crops such as rice, little and kodo millets, red gram, moth bean, jute, pepper, cardamom, many vegetables and fruit species. These plants were identified from the wild, selected and cultivated by Indian farmers over hundreds of years. The present wealth of varieties in India includes both crops that originated in the country and those that were introduced from the other countries during the distant and recent paste are soybean, sunflower, oil pail and kiwi fruit.
The Indian economy is predominantly rural and agriculture oriented. In agriculture, 85% of the holdings are less than two hectares and the declining trend in the average size of the farmer holdings, poses a serious problem. Majority of them are dry lands, which depend on erratic monsoon rains. The rest of the area is cultivated with supplemental irrigation. The farmers concentrate mainly on crop production, which is invariably subjected to a high degree of uncertainly income and employment.
In India the cultivable land is 143.8 million hectares and there is very little possibility of extending it further. Therefore, to meet the requirement of food grains for increasing population, the only option open is through time and effective space utilization in agriculture. The time concept relates to increasing the intensity of cropping under assured irrigated conditions, whereas space utilization pertains to building up of vertical dimension through multi-tier cropping and farming system approach. Thus by making use of these time and space concept either in irrigated or in rained areas, the productivity per unit area per unit time can be substantially enhanced. Therefore the only way to increase an agricultural production in the small/marginal units of farming is to increase is to increase the productivity per unit time and area. This may be achieved of quicker maturing varieties with equal yields or by improving techniques of culture, fertilizer use, weed and pest control.
The green revolution in mid sixties stirred by research based new technological developments involving new materials, models and ways of organizing farm inputs (water, fertilizer, chemical etc) and government’s policies transformed the agriculture dramatically. The outcome chewed a many fold increase in production and productivity viz. food grain production of 211 million tones ( which was only 74.23 million tones in 1966-67 ) and food grain productivity of 1697 kg/ha ( which was only 644 kg/ha in 1966-67 ). The country thus became self sufficient in food production despite tremendous pressure to sustain 16% of world human population and 10% of cattle population with just 2.4% of total land.
However modern crop production technology has considerably raised output but has residues in farm produce, gene erosion of fossil fuel based inputs such as fertilizer, pesticide, herbicides and labour spacing but energy intensive farm machinery. Land water and plant (bio diversity) are the natural resources and conservation of these natural resources is vital important. As far as resources degradation is concentrated, India is facing top soil depletion, falling ground water table and contamination of water, ecological imbalance due to deforestation and healthy hazards linked to increase use of toxic agro- chemical because of increase in food consumption. The adverse soil loss is estimated to be over 16 tones/ha/year, which is layer of top soil. Annual top soil loss is 6000 million tones, which carries about 8.4 million tones of nutrients and it is more than what we are using today. Similarly tat energy research institute ( TERI ) reported that more than 10% of GDP is being lost annually on account of environment and around 11-26% of country’s apicultural output is lost on account of soil degradation.
Sustainable agriculture
In India progress in agriculture was through explitation of recourses to serve the interest of rules in the power. In the post- independence era, we were faced with the difficult task of feeding an increasing population and were burned by recurring import of food grains. Attending self- sufficient in food grain production was the challenges and a goal before Agriculture scientist. The element of strategy to achieve self- sufficiency in food production within a short time were to expand the area under cropping, make large investments in development of water resources, develop input supplies and market infrastructure. Developments and promotion of high yielding varities responsive to high inputs was the cornerstone for green revolution of 1970.
We are self sufficient in food grain production. Now the question arises whether to follow the same strategies, which resulted in green revolutions or to redefine them. Consideration of our past achievement new challenges and the related development worldwide can answer this question.
- Although we are now self sufficient in food grain production, the per capital availability has not increased significantly and a large fraction of population are still below poverty line due to lack of purchasing capacity.
- At the present, growth rate of 2 % per annum, we will be about 1.3 billion by 2025 and 1.6 billion by 2060. hence there is need to produce more from shrinking resources base.
- Major gains in productivity and production in the past three ecades have been from areas, which had no serious limitation to production (adequate irrigation productive soils, ideal climate etc.) productivity and production increases was moderate in eastern and central India and Deccan plateau.
- Even in areas with no serious limitation for production, technology adopted for enhancing productivity has also simultaneous weekend the resource base resulting in a series of second – generation problems.
Modern crop production technology has considerably raised output but has created problems of land degradation pesticide residue in farm produce, gene erosion, and atmosphere and water pollution. The natural resources base is degraded and diminished and the quality of the environment sustaining human life is adversely affected. Agricultural production has sustained man and great civilization. The history of the world reveals that great civilization flourished along irrigation sources and mismanagement of these resources saw the extinction of these civilizations. With expanding population and rapid depletion and degradation of the natural resource base. Sustainable agriculture has assumed very great significance. The task of meeting the needs of the present generation without eroding the ecological assets of the future generation is receiving up priority by environmental planners.
Some of the environmental and ecological problems that emerged out of the cultivation of the High Yielding Varieties are depletion of forests, reduction in pastures, salination, water-logging, depletion of underground water-table, soil erosion, change in the soil chemistry, reduction in bio-diversity, decline in soil fertility, silting of rivers, increase in weeds, emergence of numerous new plant diseases, and health hazards.
An overview of these environmental and ecological problems has been given here.
- Salination
The saline and alkaline affected tracts, locally known as kallar or thur in Punjab and kallar or reh in Uttar Pradesh have expanded and increased in area.The problem of salinity and alkalinity can be solved by use of manure (cow dung, compost, and green manure) and by a judicious selection of leguminous crops in the rotation
- Waterlogging
Water logging is the other major problem associated with over-irrigation.The progressive and ambitious cultivators of the irrigated areas of these districts have changed their cropping patterns and have introduced rice and wheat in place of bajra, pulses, cotton, and fodder.Repeated irrigation of these crops in the summer and winter seasons have resulted into waterlogged condition, especially along the canals.
- Soil erosion
- Pollution:
- Lowering of the Underground Water-Table:
- Deforestation
- Noise Pollution:
- Health Hazards:
Green Revolution—Achievements, Problems and Prospects
Green Revolution—Achievements
The main achievements of Green Revolution may be summarized as under:
- The production and productivity of wheat, rice, maize, and bajra has increased substantially.
- India has become almost self-sufficient in the matter of staple foods.
- The double cropped area has increased; thereby intensification of the Indian agriculture has increased.
- In the areas where Green Revolution is a success, the farmers have moved from subsistent to market oriented economy, especially in Punjab, Haryana, western Uttar Pradesh, and the plain districts of Uttarakhand (Hardwar and Udhamsinghnagar).
- The adoption of High Yielding Varieties under the Green Revolution has generated more rural and urban employment.
- Green Revolution has increased the income of farmers and landless labourers, especially that of the big farmers and the semi-skilled rural workers. Thus Green Revolution has increased rural prosperity.
- Green Revolution has created jobs in the areas of biological (seed fertilisers) innovations, and repair of agricultural equipments and machinery.
Green Revolution—Problems and Prospects
- Depletion of soil owing to the continuous cultivation of soil exhaustive crops like rice and wheat.
- Depletion of underground water table due to over-irrigation of more moisture requiring crops like rice and wheat.
- Green Revolution has increased the income disparity amongst the farmers.
- Green Revolution led to polarization of the rural society. It has created three types of conflicts in the rural community, namely, between large and small farmers, between owner and tenant farmers, between the employers and employees on agricultural farms.
- Green Revolution has displaced the agricultural labourers, leading to rural unemployment. The mechanical innovations like tractors have displaced the agricultural labour. 6. Agricultural production in the Green Revolution areas is either stationary or has shown declining trend.
- Some valuable agricultural lands have submerged under water (water-logging) or are adversely affected by salinity and alkalinity.
- Green Revolution is crop specific. It could not perform well in the case pulses and oil-seeds.
- The traditional institution of Jijmani system has broken. Consequently, the barbers, carpenters, iron-smith, and watermen have migrated to the urban areas.
- The soil texture, structure, soil chemistry, and soil fertility have changed.
- About 60 per cent of agricultural land in the country remains unaffected by Green Revolution.
- Green Revolution technologies are scale neutral but not resource neutral.
- Punjab feeds the nation but farmers in the state, especially in the Malwa region fall prey to cancer. The take ‘Cancer Train’ to Bikaner for cheap treatment.
Organic farming is an alternative agricultural system which originated early in the 20th century in reaction to rapidly changing farming practices. Organic farming continues to be developed by various organic agriculture organizations today. It relies on fertilizers of organic origin such as compost manure, green manure, and bone meal and places emphasis on techniques such as crop rotation and companion planting. Biological pest control, mixed cropping and the fostering of insect predators are encouraged. In general, organic standards are designed to allow the use of naturally occurring substances while prohibiting or strictly limiting synthetic substances. For instance, naturally occurring pesticides such as pyrethrin and rotenone are permitted, while synthetic fertilizers and pesticides are generally prohibited. Synthetic substances that are allowed include, for example, copper sulfate, elemental sulfur and Ivermectin. Genetically modified organisms, nanomaterials, human sewage sludge, plant growth regulators, hormones, and antibiotic use in livestock husbandry are prohibited. Reasons for advocation of organic farming include advantages in sustainability, openness, self-sufficiency, autonomy/independence, health, food security, and food safety.
Organic farming methods combine scientific knowledge of ecology and modern technology with traditional farming practices based on naturally occurring biological processes. Organic farming methods are studied in the field of agroecology. While conventional agriculture uses synthetic pesticides and water-soluble synthetically purified fertilizers, organic farmers are restricted by regulations to using natural pesticides and fertilizers. An example of a natural pesticide is pyrethrin, which is found naturally in the Chrysanthemum flower. The principal methods of organic farming include crop rotation, green manures and compost, biological pest control, and mechanical cultivation. These measures use the natural environment to enhance agricultural productivity: legumes are planted to fix nitrogen into the soil, natural insect predators are encouraged, crops are rotated to confuse pests and renew soil, and natural materials such as potassium bicarbonate and mulches are used to control disease and weeds. Genetically modified seeds and animals are excluded.
While organic is fundamentally different from conventional because of the use of carbon based fertilizers compared with highly soluble synthetic based fertilizers and biological pest control instead of synthetic pesticides, organic farming and large-scale conventional farming are not entirely mutually exclusive. Many of the methods developed for organic agriculture have been borrowed by more conventional agriculture. For example, Integrated Pest Management is a multifaceted strategy that uses various organic methods of pest control whenever possible, but in conventional farming could include synthetic pesticides only as a last resort.
Soil managements Organic farming relies heavily on the natural breakdown of organic matter, using techniques like green manure and composting, to replace nutrients taken from the soil by previous crops. This biological process, driven by microorganisms such as mycorrhiza, allows the natural production of nutrients in the soil throughout the growing season, and has been referred to as feeding the soil to feed the plant. Organic farming uses a variety of methods to improve soil fertility, including crop rotation, cover cropping, reduced tillage, and application of compost. By reducing tillage, soil is not inverted and exposed to air; less carbon is lost to the atmosphere resulting in more soil organic carbon. This has an added benefit of carbon sequestration, which can reduce green house gases and help reverse climate change.
Plants need nitrogen, phosphorus, and potassium, as well as micronutrients and symbiotic relationships with fungi and other organisms to flourish, but getting enough nitrogen, and particularly synchronization so that plants get enough nitrogen at the right time (when plants need it most), is a challenge for organic farmers. Crop rotation and green manure (“cover crops”) help to provide nitrogen through legumes (more precisely, the Fabaceae family), which fix nitrogen from the atmosphere through symbiosis with rhizobial bacteria. Intercropping, which is sometimes used for insect and disease control, can also increase soil nutrients, but the competition between the legume and the crop can be problematic and wider spacing between crop rows is required. Crop residues can be ploughed back into the soil, and different plants leave different amounts of nitrogen, potentially aiding synchronization. Organic farmers also use animal manure, certain processed fertilizers such as seed meal and various mineral powders such as rock phosphate and green sand, a naturally occurring form of potash that provides potassium. Together these methods help to control erosion. In some cases pH may need to be amended. Natural pH amendments include lime and sulfur, but in the U.S. some compounds such as iron sulfate, aluminum sulfate, magnesium sulfate, and soluble boron products are allowed in organic farming.
The economics of organic farming, a subfield of agricultural economics, encompasses the entire process and effects of organic farming in terms of human society, including social costs, opportunity costs, unintended consequences, information asymmetries, and economies of scale. Although the scope of economics is broad, agricultural economics tends to focus on maximizing yields and efficiency at the farm level. Economics takes an anthropocentric approach to the value of the natural world: biodiversity, for example, is considered beneficial only to the extent that it is valued by people and increases profits. Some entities such as the European Union subsidize organic farming, in large part because these countries want to account for the externalities of reduced water use, reduced water contamination, reduced soil erosion, reduced carbon emissions, increased biodiversity, and assorted other benefits that result from organic farming. Traditional organic farming is labor and knowledge-intensive whereas conventional farming is capital-intensive, requiring more energy and manufactured inputs. Organic farmers in California have cited marketing as their greatest obstacle.
Productivity
Studies comparing yields have had mixed results. These differences among findings can often be attributed to variations between study designs including differences in the crops studied and the methodology by which results were gathered.
A 2012 meta-analysis found that productivity is typically lower for organic farming than conventional farming, but that the size of the difference depends on context and in some cases may be very small. While organic yields can be lower than conventional yields, another meta-analysis published in Sustainable Agriculture Research in 2015, concluded that certain organic on-farm practices could help narrow this gap. Timely weed management and the application of manure in conjunction with legume forages/cover crops were shown to have positive results in increasing organic corn and soybean productivity.
Organic farming also known as ecological agriculture8 or biodynamic agriculture,9 works in harmony with nature i.e. the agricultural practices followed in organic agriculture do not cause any harm to the environment. Due to eco-friendly nature of the organic farming it is considered as an viable alternative in comparison to chemical based farming, in a scenario where excessive use of chemical based fertilizers and pesticides have raised the concerns for ecotoxicity and health hazards. Nutrient management in organic agriculture is based on agronomic practices like crop rotations, soil fertility building via nitrogen and nutrient recycling using organic material like crop residues, farmyard manure and minimization of use of chemical based fertilizers.Control of pest populations in organic farming relies on use of resistant crops, crop rotation, increase in predators for natural control of the pests and increase in genetic diversity along with the judicious use of water resources and animal husbandry.
While extensive use of pesticides and fertilisers increase crop production, they also create the burning issues relevant to food quality. That’s why, the modern world has begun to focus on food quality not quantity, and is shifting towards organic agriculture.
Organic agriculture is a holistic production management system which promotes and improves health of agro ecosystem including biodiversity, biological cycles, and soil biological activity.Organic fertilisers include animal and green manure, fish and bone meal, and compost.
And the organic pest management focuses on prevention through such method as: growing resistant varieties of crops and in the proper season of the variety; improving soil health to resist soil pathogens and promote plant growth; rotating crops; encouraging natural biological agents for control of disease, insects and weeds; using physical barriers for protection from insects, birds and animals; modifying habitat to encourage pollinators and natural enemies of pests etc.
Today, insect pest management in organic agriculture involves the adoption of scientifically based and ecologically sound strategies as specified by the international and national organic production standards. These include a ban on synthetic insecticides and, more recently, on growing curbs on genetically modified organisms (GMOs).
The General Assembly of the International Federation of Organic Agriculture Movements has approved four principles of organic agriculture: health, ecology, fairness and care.
Principles apply to agriculture in the broadest sense, including the way people tend soils, water, plants and animals in order to produce, prepare and distribute goods. They are concerned the way people interact with living landscapes, relate to one another and shape the legacy of future generations. Each principle is followed by an action oriented explanation.
Various techniques are utilised for farming organically, some extensively, others rarely. Biodynamic farming stress biological methods in regard to humane treatment of animals, food quality and soil health (such as green manures, cover crops and composting).
The other method is natural farming. There is no water, no pesticide, no fertiliser and no herbicide utilisation except seed sowing. It is also known as ecological farming solely established by a Japanese farmer. Another farming practice is principally ‘bio intensive,’ which uses low energy input, fosters healthy soils, and conserves space, while maximising yields and increasing sustainability. Some others are permaculture, no-tilling and holistic management etc.
The issue has also to be seen in the context of gross domestic product (GDP) which is supposed to measure the wealth of nations and has emerged as the dominant concept in our times. However, economic growth hides the poverty it creates through the destruction of nature, which, in turn, tends to deprive communities of the capacity to provide livelihood for themselves.
Organic products are usually more expensive than ‘conventional’ agricultural products because there is an ‘extra cost’, called ‘organic premium’ to be paid in addition to the ‘reference price’. Some of the key factors that make organic products expensive include health and nutritional concerns, superior taste, food-safety concerns, and environmental friendliness. Consumer’s willingness to pay more represents a price premium for environmental quality and health.
However, when a farmer starts organic farming, the land, soil and the environment is not as good as it should be. With the organic farming practices over time, the land and environment becomes poison-free and totally healthy for growing of healthy crops, and farmer also acquires experience of organic farming.
So, on the start of almost fifth year, organic farming gives outcomes comparable with modern synthetic agricultural practices. If we critically compare the inputs, we come to know, as no synthetic fertiliser and pesticide is added, the organic farming requires less cost. On the other hand, due to its premium quality, it is sold at 3-4 times higher prices than other produces and farmers earn 3-4 times more profit.
Sustainability means keeping an effort going continuously. So, sustainable agriculture means successful management of resources for agriculture to satisfy the changing human needs, while maintaining or enhancing the quality of environment and conserving natural resources.
Sustainable agriculture can be achieved by adopting;
- Mixed farming
- Mixed cropping
- Crop rotation
- Crop selection
- Varietal improvement
The practice of cultivating two or more crops simultaneously on the same piece of land is called mixed cropping. During mixed cropping, if one crop faces adverse conditions or pathogen attack then the other crop can be saved.The basic objective in mixed cropping is to minimize the risk and insure against the crop failure due to abnormal weather conditions. Eg wheat + mustard, groundnut+ sunflower etc.
Criteria for the selection of crops during mixed cropping:
- Crops should have different maturation time.
- Both crops should have different water requirements.
- The nutrient requirement of one crop should be lesser than the other.
- If one crop is deep rooted, the other has shallow roots.
- If one crop is tall, other should be dwarf.
Advantages of mixed cropping:
- Increase in yield
- Optimum utilization of soil
- Minimum pest infestation
- No risk of crop failure
- Farmers can harvest varieties of produce at the same time