Land Use and Agriculture

Since the very early moments of human civilisation, we have been farming the land. From basic hunter gatherers to massive agricultural producers, humans are reliant on land and how this land is used. There have been various approaches as to how land is used, what is farmed and how it is farmed. Early farmers were getting big returns from their crops, however unsustainable land use sparked a change in the way things were done, especially from the mid 1960's and onwards. This article will discuss the early days of farming, through to modern practices and also how farmers and agricultural producers have dealt with and are dealing with pests.

Hunter Gatherers

Many of us are used to modern agricultural techniques and consider it to be the superior way of life. But in reality hunter-gatherers do not find themselves in the ongoing battle with famine, droughts, pests or weather events as the modern agriculturalists do. There have been many examples in Africa where farmers and people reliant of farming have starved, whereas the simple hunter-gatherers, or in this case the Kalahari Bushmen, survived remarkably well. It is believed that one of the reasons for this case of survival is that hunter-gatherers keep their community or tribal sizes fairly small in comparison with other ways of life, and they do not over burden the territory from which their food comes from. This small population does not come as an accident or due to famines or disease, it is just a case of making a concerted effort to keep their population in check. Most Kalahari Bushmen tribes do not marry early, prolong breast feeding of their infants and even practice forms of abortion in order to do this.

The Bushmen actually tend to have a better balanced diet than their farming dependant counterparts, and their rates of chronic and other diseases are lower in comparison, with life expectancies that can match any parts of the western world. They also only spend an average of fifteen hours a week dedicated to hunting and collecting food, even though they live in harsh locations. Generally the children won't need to work until they are married, and they have a very good tradition of looking after the sick and elderly. In comparison, people who live in urbanised or agricultural societies need to work an average of 60 hours a week, with most of their incomes directed to the purchase of food and drink 1).

When comparative palaeontological studies were done between humans from post and pre agricultural times, results showed that the average mature stature of people fell by 5%, as life expectancy, and things such as infectious diseases, bone deformities, developmental abnormalities and mortality went up. The first signs of arthritic deterioration of joints was seen in post agricultural times. Whilst agriculture provided more food for a greater number of people, there was a big trade off in the amount of time that was required in order to keep the people fed. This is turn has led to people spending a large portion of their time working, and also making children work, which was not seen in the hunter gatherers. Agriculture is not only by far the most resource intensive activity that is undertaken by man in this planet it also causes the greatest amount of environmental impacts. Of the 80,000 plant species on earth, only around 30 are edible and they are mainly the big four – corn, rice wheat and potato. Over 50% of grain that is harvested and 35% of fish harvested are fed to grazing animals 2).

History Of Agriculture

Early societies were hunter gatherers that relied completely on natural plant and animal products. A very early invention was weapons which could be used by hand, which gave the hunter the ability to capture and kill animals which a defenceless creature like us could never hope to kill without such a weapon and started what is now a tradition of violence and warfare against other humans. Approximately 15,000 years ago some people in the Middle East noted that emmer (wild wheat) grains which had dropped around the camp would grow and start to produce grain near to where people were temporarily staying. This was the first idea of the possibility of agriculture. Armed with superior hunting skills, a very basic agricultural concept people were able to settle somewhat permanently in the one place, and hence the first villages started to appear, which was around 10,000 years ago. Life in villages and agriculture go hand-in-hand, as the area near any regions of settlement cannot support hunter gatherers permanently and yet there is no advantage in planting a crop if there is no one around to be able to harvest it 3).

Like plants, some animals were also brought under the control of humans, and almost all domesticated animals are originally from the north of Africa, the Middle East and south eastern Mediterranean. People have not domesticated a plant or animal which is of major importance in approximately the last 9000 years. Advances in agriculture occurred in the 15th to 18th centuries, when different foods from around the globe were spread to new lands and new markets. There was another advance in the 18th and 19th centuries with understanding of plant and animal nutrition and mechanisations of agriculture. It is most likely that historians will record yet another leap in agriculture in the 20th century with further progress in the fields, quickly followed by agrochemical technology and, in the 21st century, the emergence of genetic engineering. There are several different types of agricultural systems in used worldwide at the moment, some sustainable, some maybe outdated, others new but ultimately unsustainable 4).

Agricultural Energy

For a long period of time, agriculture in western countries has been reliant on and subsidised by fossil fuels. One of the most energy inefficient agricultural practices in open sea fishing. The amount of energy that is used for the construction and maintenance of the fishing vessels far outweighs the amount of fish and other marine animals that are caught. During the better times, the catch to energy usage ratio was 1 to 6, and in modern times this is much worse, which is 1 in 36. The energy usage of storage, preparation and distribution is not even calculated in this figure. In most western countries the amount of energy used overall for food production, growing and all other facets is around 1 unit of food to 10 units of energy. This ration is inverse for most less developed countries, and approximately 80% of all fossil fuels burnt on the planet are used for the production of food. As fossil fuels become more scarce and in turn more expensive, this will ultimately affect the prices of food worldwide 5).


Commercial Fishing Trawler 6)

The Green Revolution

Some farmers and agriculturalists have decided to take a different approach to growing crops and food production, and that is by adopting techniques and different crop varieties from lesser developed countries. This started in the 1960's and was thought to have originated in Mexico and was called the gree revolution. The crops that are grown, such as wheat and rice, are shorter which gives them less growing time, grow at a uniform rate and also grow faster whilst producing at least two crops per year where there would normally be only one crop per year. Between the years 1950 and 1970 Mexico showed a 800% increase in crop yields using these techniques. India also did well by doubling it's crop yields and even had enough surplus to be able to export rice and wheat. As most things however, there is always a cost. The green revolution crops require high levels of water and fertiliser and are not very resistant to insects and pests. In order to maintain these high yield crops the capital investment needs to be significant, and this is not always possible. This has created a situation where most of the farmers needed to borrow money from banks in order to be able to compete with large commercial agricultural producers which resulted in many farmers being unable to pay their debts and losing their farms.


Canola Field 7)

The green revolution also made it to less developed countries, which in turn resulted in a increase in the use of fossil fuels in order to harvest and maintain the high yield crops. This also resulted in high levels of debt for governments and farmers, and also damage to farming soils. The sowing of these crops gives the soil less time to recover and creates major loss in natural nutrition. The increase in irrigation also raises the levels of salinization which can render the land useless in several short years. Many countries have had to increase the levels of pesticides that are being used on these crops as they do not have a good natural resistance to them, and this also increases costs and does damage to the local environments. As a result many green revolution crops have started to fail, and this is most evident in the tropics where there are a greater amount of pests. It has become so widespread that the crops are now yielding less than the original non green revolution crops.

Unfortunately most farmers are now reliant on green revolution crops, so even despite low yields, they keep on harvesting these crops at low rates of return and high energy usages. This is a symptom of arrogant western scientists assuming that such crops could be grown in all types of weather and climate conditions and blindly believing that this sudden high yield crop will come with no negative impacts or costs. The adoption and continual use of green revolution crops is constantly draining the land of nutrients, increasing the demand for fertilisers and water, so in basic terms is looking at short term gain which will cause long time problems 8).


Pests can be defined as any type of organism which causes harm, nuisance or loss to humans. This can range from stray dogs to noxious weeds and everything in between. When it comes to agriculture, pests are divided into three main groups. Weeds can cause great damage to crops and can take over, strangle or starve other types of vegetation from growing. A weed is generally called a pest when it is growing where we don't want it, or example most grasses are a type of weed and we are happy if they grow in our front yard, but are undesirable in our vegetable patch. Fungi or fungus is another type of pest, which can be in the form of mushrooms which compete with crops or in the form of mildew and rust. Fungi can also cause harm to humans and animals if the spores are inhaled into the lungs or just by contact on the skin. The third type of pest is insects, and these are by far the most damaging out of all. It is estimated that 35% of all crops grown worldwide are consumed by insects before humans even get to them, and can have many different effect on crops such as simply eating the leaves, boring into stems and fruit and also spreading disease from plant to plant. Over the years there have been different methods of combating pests, from the simple scarecrow to complex pesticides 9).


Although most pesticides came into mass use post World War II, the Chinese have been using forms of pesticides for over 2000 years, such as Pyrethrum, which is a naturally occuring pesticide within the crysanthenum flower. Many modern pesticides have had good short term effects however there are very few that can have ongoing success. In order for a pesticide to be effective it needs to meet certain criteria such as only killing the target pest and not be harmful to pollinators, being able to chemically break down in a short period of time, prevent the genetic resistance by the target species, ensure that the cost of the pesticide does not exceed the amount of crop saved and have a cost benefit in comparison to non chemical means.


Crop Spraying 10)

Being able to control pests effectively has several benefits and can reduce food costs and increase availability. Pesticides have also had positive health effects on humans, such as DDT which controlled vector borne diseases such as malaria during and shortly after World War II. Like most things the use of pesticides is not a huge problem when done so in a controlled manner. When the use is on a larger scale problems start to occur, such as:

  • The target species is poisoned but the poisoned animal or weed is eaten by a different animal, poisoning it also
  • Insects that are not targeted are also killed
  • Insects that are predators of disease spreading insects are killed, increasing spread of disease
  • The chemicals build up in the soil and waterways
  • Possible contamination of crops

When DDT was used on mass post World War II, it created a multitude of problems. The human effects have been well documented but many animals also suffered. The chemical caused a reduction in the thickness of eggshells in many birds, almost causing the extinction of the American Bald Eagle. DDT was unfortunately a chemical that built up and did not break down organically, and caused it to move through the food chain. This means that it fails as a effective pesticide as per the requirements outlined above. Despite all efforts to reduce the use of harmful chemicals, more than 300 tonnes of herbicides and pesticides still flow into the Mississippi River and out to the Gulf of Mexico every year 11). Most organochlorine based pesticides have very long lasting effects, and every vertebrate on the planet contains some sort of chemical in their systems, even the penguins in Antarctice. Sandy soils allow chemicals to drain out quickly from the area but does not break them down at all. Clay holds the chemicals in the soil for longer, but also helps the process of breaking them down. If the soil is too alkaline or too acidic, this can also hinder the breakdown process. 12).

The secondary problem with pesticides is ineffectiveness or a building up of tolerance by the target species. Most pesticides can be extremely effective in the short term but currently there are no products that tick all the boxes as a succesful control method. Even some weeds that can be targeted and killed exclusively can regenerate from the seeds that are left behind. Another negative effect can be the creation of pests. In midwest region of the United States, coyotes were a problem because they were stealing lambs and other baby animals. The authorities decided to bait the coyotes to reduce their numbers however whilst this was effective, there was a population explosion in ground squirrels, who are the natural prey of the coyote also. This lead the squirrels to require greater amounts of food and the crops started to become affected.


Whilst the population of the earth is growing at an extremely high rate, it is increasingly important that we select the correct and sustainable methods for farming and agriculture. There is an increasing number of large scale agricultural projects that are extremely energy intensive and water thirsty. Unfortunately we are living on a planet with finite resources, and the line needs to be drawn somewhere. The use of green revolution crops and many pesticides whilst extremely succesful in the short term have proven to be unsustainable in longer time frames. We need to be able to work smarter but not harder in order to maintain enough food for everyone on the planet. Unfortunately this may not be possible at the current rates of population, with the global population tipped to go past the 7 billion mark in 2014. Most will argue that we are far beyond the carrying capacity of the planet and at some stage in the near future we will see some potentially devastating effects.


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