LECTURE                                 SELECTED TOPICS IN ECOLOGY

In this lecture you will learn about:

Go HERE and read about the GREEN REVOLUTION

There were three basic elements in the method of the Green Revolution:
 1) Continued expansion of farming areas;
 2) Double-cropping existing farmland;
 3) Using seeds with improved genetics.

Why A Green Revolution?
What was the Green Revolution in India?
Statistical results of the Green Revolution?
Economic results of the Green Revolution?
Sociological results of the Green Revolution?
Political results of the Green Revolution?
Limitations of the Green Revolution?
Who's hungry? And how do we know? Food shortage, poverty, and deprivation.   IS THERE A FOOD SHORTAGE?
Go HERE to read about 
    Causes of food poverty
What are the causes of food poverty
Look specifically at "Distribution"
Go HERE to read about
    Conflict as a cause of hunger
 What contributes to widespread hunger? 
"Food shortage

Those most at risk of food shortage tend to be located in conflict zones, where food cannot reach them. Weather and hazardous climatic or environmental conditions are less important than politics influencing food production and distribution. Active and post-conflict zones suffering food shortage predominate in sub-Saharan Africa and, to a lesser degree, in South-East and western Asia. Conflict zones, even if they are receiving food aid, tend to be food poor. Social and climatic disaster usually combine to create situations of resource poverty that set the stage for chronic food poverty for years to come.

Seasonal or periodic hunger constitutes the second general case of food shortage. This persists outside conflict zones in local settings where food production combined with other economic activities is insufficient to support adequate diets year-round or from year to year where single-year productivity is variable and low. Increasingly, these pockets of food shortfall are reached by intervention programmes, that provide relief food, often through "food-for-work" employment programmes, Where markets or food relief penetrate relatively isolated local food systems, as in many parts of Africa and South Asia, food shortage is removed but is replaced by chronic food poverty (Messer 1989)."


So, the Green Revolution did help increase total food output, but the news is not all good. The technologies of the green revolution should be looked at as the plant equivalent of steroid use in human athletes. A jock that uses steroids will gain muscle and strength faster and have a competitive advantage. cartoon image of crop duster plane But the big boost is not sustainable over a long period of time, and the negative side effects are well known and often catastrophic to the athlete.

In the case of Green Revolution farming, the chemicals used pollute our land, air, and water; the switch from heavily rotated multiple crops to mono-cropping or dual-cropping reduces total soil fertility and the nutritional value of our food; and the lower number of seed varieties used reduces the genetic diversity found in crops, thus endangering the stability of farm output in the future. The side effects related to soil fertility and genetic diversity will ultimately take their toll. Indeed, yield increases in today's farm fields have generally leveled off and, in cases such as rice and wheat, yields are beginning to decline in some areas.

Let's be a little more specific about the problems associated with Green Revolution farming:

    * Farmers, farm workers, and all of us are continually exposed to chemical pesticides due to their widespread use, with each of us carrying a body burden of the toxins.
    * Countless numbers of streams, rivers, and drinking water sources are degraded due to pesticide and fertilizer runoff.
    * Major portions of bays and gulfs are oxygen-starved coastal dead zones due to algal blooms that are fed by fertilizer runoff.
    * Wildlife suffer from genetic mutations due to the farming chemicals that contaminate their ponds and swamps. Notable examples: Genetic mutations in frogs and abnormal genitalia in alligators.
    * State advisories for locally caught fish are chock-full of warnings about fish species contaminated with pesticides." CITATION

"The following sections in these notes address implications of the green revolution for:
Diminished "biodiversity" in crops
Inherent soil fertility and water quality
Pesticides and
Land degradation
Prospects for sustainable agriculture are addressed in notes on that topic." CITATION

                                                  "The Myth of High Yields

The term “high-yielding varieties” is a misnomer, because it implies that the new seeds are high yielding of themselves. The distinguishing feature of the seeds, however, is that they are highly responsive to certain key inputs such as fertilizers and irrigation water. The term “high responsive varieties” is thus more appropriate.

In the absence of additional inputs of fertilizers and water, the new seeds perform worse than indigenous varieties. The gain in output is insignificant compared to the increase in inputs. The measurement of output is also biased by restricting it to the marketable elements of crops. But, in a country like India, crops have traditionally been bred to produce not just food for humans, but fodder for animals and organic fertilizer for soils. In the breeding strategy for the Green Revolution, multiple uses of plant biomass seem to have been consciously sacrificed for a single use. An increase in the marketable output of grain has been achieved at the cost of a decrease in the biomass available for animals and soils from, for example, stems and leaves, and a decrease in ecosystem productivity due to the over-use of resources.

Significantly, much of the increased yield obtained by planting the new HYV varieties consists of water. Increasing the nitrogen uptake of plants through using artificial fertilizers upsets their carbon/ nitrogen balance, causing metabolic problems to which the plant reacts primarily by taking up extra water.

India is a centre of genetic diversity of rice. Out of this diversity, Indian peasants and tribals have selected and improved many indigenous high yielding varieties. Comparative studies of 22 rice growing systems have shown that indigenous systems are more efficient when inputs of labour and energy are taken into account.2

                                                   Loss of Diversity
Diversity is a central principle of traditional agriculture in the Punjab, as in the rest of India. Such diversity contributed to ecological stability, and hence to ecosystem productivity. The lower the diversity in an ecosystem, the higher its vulnerability to pests and disease.

The Green Revolution package has reduced genetic diversity at two levels. First, it replaced mixtures and rotations of crops like wheat, maize, millets, pulses and oil seeds with monocultures of wheat and rice. Second, the introduced wheat and rice varieties came from a very narrow genetic base. Of the thousands of dwarf varieties bred by Borlaug, only three were eventually used in the Green Revolution. On this narrow and alien genetic base the food supplies of millions are precariously perched.

                                                  Increasing Pesticide Use
Because of their narrow genetic base, HYVs are inherently vulnerable to major pests and diseases. As the Central Rice Research Institute, in Cuttack, India, notes of rice: “The introduction of high yielding varieties has brought about a marked change in the status of insect pests like gall midge, brown planthopper, leaf-folder, whore maggot, etc. Most of the high-yielding varieties released so far are susceptible to major pests with a crop loss of 30- 100 per cent.”3 Even where new varieties are specially bred for resistance to disease, “breakdown in resistance can occur rapidly and in some instances replacement varieties may be required every three years or so.”4 In the Punjab, the rice variety PR 106, which currently accounts for 80 per cent of the area under rice cultivation, was considered resistant to whitebacked planthopper and stem rot when it was introduced in 1976. It has since become susceptible to both diseases, in addition to succumbing to rice leaf-folder, hispa, stemborer and several other insect pests.

The natural vulnerability of HYVs to pests has been exacerbated by other aspects of the Green Revolution package. Large-scale monoculture provides a large and often permanent niche for pests, turning minor diseases into epidemics; in addition, fertilizers have been found to lower plants’ resistance to pests. The result has been a massive increase in the use of pesticides, in itself creating still further pest problems due to the emergence of pesticide-resistant pests and a reduction in the natural checks on pest populations.

The “miracle” seeds of the Green Revolution have thus become mechanisms for breeding new pests and creating new diseases. Yet the costs of pesticides or of breeding new “resistant” varieties was never counted as part of the “miracle” of the new seeds.

                                                          Soil Erosion
Over the centuries, the fertility of the Indo-Gangetic plains was preserved through treating the soil as a living system, with soil-depleting crops being rotated with soil building legumes. Twenty years of “Farmers’ Training and Education Schemes”, however, have transformed the Punjab fanner into an efficient, if unwilling, “soil bandit”.

Marginal land or forests have been cleared to make way for the expansion of agriculture; rotations have been abandoned; and cropland is now used to grow soil depleting crops year-in, year-out. Since the start of the Green Revolution, the area under wheat, for example, has nearly doubled and the area under rice has increased five-fold. During the same period, the area under legumes has been reduced by half. Today, 84 per cent of the Punjab is under cultivation, as against 42 per cent for India as a whole. Only four per cent of the Punjab is now “forest”, most of this being plantations of Eucalyptus.5

The result of such agricultural intensification has been “a downward spiraling of agricultural land use - from legume to wheat to wasteland.”6 The removal of legumes from cropping patterns, for example, has removed a major source of free nitrogen from the soil. In addition, the new HYVs reduce the supply of fodder and organic fertilizer available to farmers. Traditional varieties of sorghum yield six pounds of straw per acre for every pound of grain. By contrast modem rice varieties produce equivalent amounts of grain and straw. This has contributed to the thirty-fold rise in fertilizer consumption in the state since the inception of the Green Revolution.

Increased fertilizer use, however, has not compensated for the over-use of the soil. High-yielding varieties rapidly deplete micronutrients from soils and chemical fertilizers (unlike organic manures which contain a wide range of trace elements) cannot compensate for the loss. Micronutrient deficiencies of zinc, iron, copper, manganese, magnesium, molybdenum and boron are thus common. In recent surveys, over half of the 8706 soil samples from the Punjab exhibited zinc deficiency, reducing yields of rice, wheat and maize by up to 3.9 tonnes per hectare.

Partly as a result of soil deficiencies, the productivity of wheat and rice has declined in many districts in the Punjab, in spite of increasing levels of fertilizer application.

                                                      Water Shortages
Traditionally, irrigation was only used in the Punjab as an insurance against crop failure in times of severe drought. The new seeds, however, need intensive irrigation as an essential input for crop yields. Although high-yielding varieties of wheat may yield over 40 per cent more than traditional varieties, they need about three times as much water. In terms of water use, therefore, they are less than half as productive.7

One result of the Green Revolution has therefore been to create conflicts over diminishing water resources. Where crops are dependent on groundwater for irrigation, the water table is declining at an estimated rate of one-third to half a metre per year. A recent survey by the Punjab Directorate of Water Resources, has shown that 60 out of the 118 development blocks in the state cannot sustain any further increase in the number of tube wells." CITATION


                                                        THE PEOPLE
'Green Revolution' Trapping India's Farmers In Debt
 Green Revolution blamed for farmers' suicides


1. MONOCULTURE or the planting of mile after mile of the same species of crop like grains or soybeans or rice.  This lack of diversity means that it is highly UNSTABLE.  The primary problem with monoculture is that any pest, virus, bacteria, fungus, insect  can quickly reproduce and wipe out the entire crop. OR, bad climate will wipe out the entire crop.  The potato famine in Ireland was an example of relying on a single crop that was hit with devastating disease that wiped out the main staple of their diet

2.  HYBRID SEED, (like high yield) are genetically identical which means there is no genetic diversity that could have resistance to pests or disease.

Planting unsuitable crops like planting corn in dry areas and irrigating rather than planting crops more suitable and tolerant of drought.  As humans migrated, they brought their "foods" with them and didnt shift entirely to the crops growing naturally in their new habitat. This is enormously compounded by planting "cash crops" to sell rather than a variety of different crops to eat.


Anyone remember the explosion Dec. 3, 1984 when Methyl isocyanate (MIC) gas leaks from a Union Carbide India Limited (UCIL) pesticide plant in Bhopal, India?

"The Bhopal facility was part of India's Green Revolution aimed to increase the productivity of crops.  Considered an essential factor in the effort to achieve self-sufficiency in agricultural production, pesticide production use increased dramatically during the late 1960's and early 1970's.  The decision to manufacture the pesticides in India, as opposed to relying on imports was based on India's goal of preserving foreign exchange and its policy of industrialization (Cassels, p.39).  In 1969, Union Carbide (UCC-the parent company) set up a small plant (Union Carbide India Ltd.- UCIL) in Bhopal, the capital city of Madhya Pradesh, to formulate pesticides."  CITATION

What are the failures of the "green revolution"?
Why is the green revolution not sustainable over the long haul?
What are the "myths of the high yields"?
What does high yield crops do to the land? 
What is the triple whammy of unstable agriculture?  What are the problems seen?
What happens when productivity is enhanced at the cost of diversity?


"Terra preta (“dark earth” in Portuguese) refers to expanses of very dark, fertile anthropogenic soils found in the Amazon Basin. It owes its name to its very high charcoal content. It is also known as “Amazonian dark earth” or “Indian black earth”. In Portuguese its full name is “Terra preta do índio” or “Terra preta de índio”. Terra mulata is lighter or brownish in color. [1]

Terra preta is characterized by the presence of low-temperature charcoal in high concentrations; of high quantities of pottery sherds; of organic matter such as plant residues, animal faeces, fish and animal bones and other material; and of nutrients such as nitrogen (N), phosphorus (P), calcium (Ca), zinc (Zn), manganese (Mn) [2]. It also shows high levels of microorganic activities and other specific characteristics within its particular ecosystem. It is less prone to nutrient leaching, which is a major problem in most rain forest soils. Terra preta zones are generally surrounded by terra comum, or "common soil"; these are infertile soils, mainly acrisols [2], but also ferralsols and arenosols[3].

Terra preta soils are of pre-Columbian nature and were created by humans between 450 BC and AD 950 [4] [5]. The soil's depth can reach 2 metres (6 feet). Thousands of years after its creation it has been reported to regenerate itself at the rate of 1 centimetre per year[6] by the local farmers and caboclos in Brazil's Amazonian basin, and they seek it out for use and for sale as valuable compost."  CITATION

James Lovelock on Biochar: let the Earth remove CO2 for us

"ATHENS, Georgia (CNN) -- Over the railroad tracks, near Agriculture Drive on the University of Georgia campus, sits a unique machine that may hold one of the solutions to big environmental problems like energy, food production and even global climate change.  Biochar's high carbon content and porous nature can help soil retain water, nutrients, protect soil microbes.

"This machine right here is our baby," said UGA research engineer Brian Bibens, who is one of a handful of researchers around the world working on alternative ways to recycle carbon.

Bibens' specialty is "biochar," a highly porous charcoal made from organic waste. The raw material can be any forest, agricultural or animal waste. Some examples are woodchips, corn husks, peanut shells, even chicken manure.

Bibens feeds the waste -- called "biomass" -- into an octagonally shaped metal barrel where it is cooked under intense heat, sometimes above 1,000 degrees Fahrenheit, the organic matter is cooked through a thermochemical process called "pyrolysis".

In a few hours, organic trash is transformed into charcoal-like pellets farmers can turn into fertilizer. Gasses given off during the process can be harnesed to fuel vehicles of power electric generators. 

Biochar is considered by many scientists to be the "black gold" for agriculture.

Its high carbon content and porous nature can help soil retain water, nutrients, protect soil microbes and ultimately increase crop yields while acting as natural carbon sink - sequestering CO2 and locking it into the ground."  CITATION

good luck on the final exam.  Live long and prosper \V/