Revision Urban Farm

Effects of Industrial Agriculture of Crops on Water and Soil

How industrial farming can interact with water and soil

An overview of water and soil ecosystems and some effects of monoculture, pesticides, nitrogen fertilizer and irrigation, practices of industrial or conventional agriculture, on these fundamental resources.

Introduction

Industrial agriculture is a form of modern farming that refers to the industrialized production of livestock, poultry, fish, and crops. "Industrial agriculture's methods are techno-scientific, economic, and political. They include innovation in agricultural machinery, farming methods, genetic technology, techniques for achieving economies of scale in production, the creation of new markets for consumption, patent protection of genetic information, and global trade."[1] For the purpose of this essay, industrial agriculture of crops is the focus and is referred to as industrial agriculture.

Its beginnings came with the Industrial Revolution, and more specifically the Green Revolution; starting mid twentieth century in the United States. Industrial agriculture is the systematic application of science to agriculture. One method of increasing crop yields through genetic engineering, mainly of three grains, maize, wheat, and rice, generally referred to as high-yielding varieties, and the accompanying technologies of pesticides, synthetic nitrogen fertilizer, and irrigation projects.[2]

A brief of Indias experience with the Green Revolution:

For two decades after the Second World War, hunger was tackled directly through the export of the US food surplus. When the economics of that system began to falter, a new system was ready to take its place, one which broke the links between trade and aid, in which private sector had an expanded role and, crucially, where breakthroughs in agricultural research made possible the vastly increased staples of wheat, corn and rice in key areas of the Global South. This research created hybrid seed varieties that yielded more than traditional ones. In order to work, the seeds required almost laboratory-perfect growing conditions, which demanded irrigation, fertilizers and pesticides. These, in their turn depend on fossil fuels for their production. And the entire enterprise required the expunging of native biodiversity, so that rows of new seed might take its place. It was a transformation of agricultural practice that well deserved the title Green Revolution. In some places, due in part to Green Revolution technologies, widespread hunger was kept in check. But the social and ecological consequences were high. Recently, in places like India, hunger has returned. In response, the companies who were central to the first Green Revolution have proposed a second generation of crops, ones that depend on genetic modification to allow for increased production, under the banner of a new green revolution. [3]

The way the food system functions has many affects on ecosystems. Further, as the dynamics of agrarian change are bound to larger social concerns all aspects are beyond the scope of this essay.

Four key features of industrial agriculture, and the synergies among them, will be discussed with effects on water and soil.

1. Monoculture of crops.
   
2. Pesticides.
3. Nitrogen-based fertilizers.
4. Irrigation.

Water

On Earth water exists as a solid (ice), liquid, or gas (water vapor). Water's state frequently changes and distribution is quite varied; many locations have a lot while others have very little.[4] Water cycles and flows through ecosystems, between bodies of water, the sky, and the earth. It's a full cycle through the biosphere; there is no beginning or end. From this constant movement water usually cleanses itself [5] and is recycled on a global scale. This complex circulation of the Earths water thorough oceans, land, and atmosphere is called the hydrologic or water cycle.

To begin the water cycle and condensation,

Condensation occurs as the temperature of the air or earth changes. Water changes stateswhen temperatures fluctuate. So when the air cools enough, water vapor has to condense on particles in the air to form clouds.

As clouds form, winds move them across the globe, spreading out the water vapor. When eventually the clouds can't hold the moisture, they release it in the form of precipitation, which can be snow, rain, hail, etc.

The next three stages: infiltration, runoff, and evaporation occur simultaneously. Infiltration occurs when precipitation seeps into the ground. This depends a lot on the permeability of theground.

Permeability is the measure of how easily something flows through a substance. The more permeable, the more precipitation seeps into the ground. If precipitation occurs faster than it can infiltrate the ground, it becomes runoff. Runoff remains on the surface and flows into streams, rivers, and eventually large bodies such as lakes or the ocean. Infiltrated groundwater moves similarly as it recharges rivers and heads towards large bodies of water.

Groundwater [9]

Soil

• Soil texture, the amount of sand, silt, or clay.
• Soil structure, the arrangement of the solid parts and the pore space between them; a result of soil organism's interactions with soil texture.
• Soil organic matter or humus.
  

Organic Compounds of Soil [11]

Soils are a non-renewable resource, formed at a rate of 1 inch every 250 to 1, 200 years under most conditions. To make agriculturally productive land it usually takes 3, 000 to 12, 000 years. Once soil is destroyed it is basically gone forever. However, soils can be cared for and their fertility maintained.[13]

Soils provide both physical support for roots and the necessary porosity for their growth; they accumulate organic matter and mineralize its constituents in order to recycle plant macronutrients; they retain and supply water and mineral micronutrients; and their microbial fauna has an irreplaceable role in biogeochemical cycling, particularly in that of three doubly mobile elements, carbon, nitrogen, and sulfur.[14]

Nitrogen can become available for plant roots to absorb by means of nitrogen-fixing bacteria and algae in soils or by external application of fertilizer; organic, based on carbon compounds, or inorganic, artificially produced. For most plants to absorb nitrogen, it must first be converted, with other chemicals into a compound they can absorb.[15]

Naturally, nitrogen-fixing bacteria in soils form a symbiotic relationship with legumes. These types of plants are very useful because they fix nitrogen from the air which enriches soils and acts as a 'natural' fertilizer. The nitrogen-fixing bacteria produce ammonia that provides a source of nitrogen for the legume to grow. Legumes not only supply their own nitrogen but also help with the nitrogen needs of crops that are inter-planted. The nitrogen-fixing crop of legumes will also leave nitrogen available in soils for nitrifying bacteria to fix for subsequent crops.[16]

Key processes transforming nitrogenous compounds within soils include assimilation (incorporating the nutrient into crops), and microbially mediated decomposition, mineralization, immobilization, enzymatic oxidation, nitrite reduction, nitrification, denitrification. Fixed nitrogen is stored in soils either as ammonium or, after oxidation by nitrifying bacteria, as a much more water-soluble nitrate.[17]

As water and soil are part of the whole Earth system they are quite complex. Complex systems are more than the sum of their identified parts. Industrial agriculture simplifies the complexity and diversity ecosystems thrive on.[18] One method of simplification is through monculture of crops.

Monoculture of Crops

Monoculture is the term for growing one plant variety at a time.[19] It is "the deliberate choice of uniformity and the continuous production of a single crop." In industrial agriculture this is practiced by focusing on a select few crops of maize, wheat, or rice.

As the three grains of maize, wheat, and rice became the focus of crops, research was done to increase the amount of grain these specific crop types produced. To do this the seeds are engineered to focus on grain creation-- diverting growth from another area, typically stalk height to create a dwarf like plant.[20] These are generally referred to as high-yielding varieties. As a consequence of their increased growth rate, high-yielding variety crops lack an important plant defense mechanisms and are more prone to persistent insects and diseases than traditional cultivars. High-yielding varieties will likely need high levels of pesticides and are modified to have heightened resistance to certain pesticides.[21]

"High-yielding plant varieties used to expand the worlds food basket have to be combined with fertilizers and pest control, and rely on irrigation at just the right moment to promote optimum growth."[22]

World Grain Production[23]

Ecosystems naturally have checks and balances. Diversity of species allows ecosystems to be more resilient to stress.[24] It is a "complex outcome of orderly competitive displacement and disruptive disturbances."[25] By subverting the balance of clearing land to grow one type of crop the natural checks and strength of diversity are eliminated. As well, inter-planting with other plants that provide the necessary habitat for natural enemies of persistent organisms is not practiced. This is why along with monoculture a high level of poisonous pesticides may be needed to keep the crop from succumbing to persistent insects or disease.

Monoculture may have temporary economic advantages for farmers, evaluations based solely on yield may show its superiority, but, genetic concerns aside, it is not an agronomic optimum because it tends to produce soil erosion and intensify weed and insect problems.[26] Soils are more prone to nutrient deficiencies as high-yielding varieties direct more growth to grain. These nutrients are harvested from the land with the grain and less plant material is being left for recycling nutrients back to the soil. Also, industrial agricultures practice of high-yielding monoculture does not make use of nitrogen fixing plants and will likely use high amounts of nitrogen-based fertilizer.

"The success of high-yielding varieties of the three main grains, along with attendant technologies of chemical fertilizers, pesticides, and sophisticated machinery, exploded the production of these crops at the expense of all others."[27]

Pesticides

As introduced with monoculture the need for pesticides is likely higher when land and ecosystem habitats are cleared for growth of only one species. High-yielding varieties may be engineered to better withstand pesticides making pesticide usage coupled with a high-yielding crop. As well, where hands on labour is subverted for agrochemical use it will be a main means of insect and disease control.

Jane Goodall describes some effects of pesticides in her book Harvest for Hope:

When chemical pesticides are first introduced into an area, insect predators will quickly be poisoned and die. But gradually, after repeated applications, some insects will build up resistance. Just as overuse of antibiotics creates antibiotic resistance in the bacteria that cause sickness in animals and humans, heavy doses of pesticides create pesticide resistance in insects. After more than fifty years of farming with pesticides, there are whole populations of pest insects that have evolved to become increasingly impervious to pesticides. The response of the farmer is to spray more often, and with increasingly toxic pesticides. Nowadays, its not uncommon for farmers to use three times as many chemicals as they needed forty years ago to kill the same insects.

And all these chemicals, of course, dont just stay on the farm: They escape into the environment. They evaporate; they sink into the soil and leach into our groundwater, reservoirs and wells; they find their way into our lakes, rivers, and oceans; and, of course, they can end up in the bodies of animals and people.[28]

World Pesticide Use

World pesticide amount used exceeded 5.0 billion pounds in 2000 and 2001. Herbicides accounted for the largest portion of total use, followed by other pesticide use, and fungicide use. Total world pesticide amount used decreased in 2001 for all pesticide types.

Nitrogen-based fertilizer

Nitrogen is an element that is interconnected with the Earth and life system. While it is not anymore critical than other parts, like phosphorus or carbon, an examination is given to its significance and industrial agricultures focus on this specific element.

There are currently nine identified major plant macronutrients required for fertility, nitrogen, phosphorus, potassium, magnesium, calcium, sulphur, oxygen, carbon, and hydrogen. They are major elements meaning not that they are more important than other nutrients, they are required in large quantities.[29]

As nitrogen is important for the growth of plants science focused on this fertilizer element with high-yield seed engineering. High-yielding varieties are engineered to increase their nitrogen-absorbing potential compared to other varieties. [30] In addition to possible excess usage this may cause, these crops take up a high amount of nitrogen and effectively remove it from the soil upon harvest. As a result, the soil will likely need high amount of nitrogen-based fertilizer on the following crop, depending on specific crop needs.

The theoretical based discovery by European researchers in 1884 of how to combine hydrogen with atmospheric nitrogen industrially, to form ammonia the compound used in most inorganic fertilizers today, marked the beginning for the manufacture of industrial fertilizers.[31]

World Fertilizer Use[32]

The growth in the world fertilizer industry after World War II was spectacular. Between 1950 and 1989, fertilizer use climbed from 14 million to 146 million tons. The period of remarkable worldwide growth came to and end when fertilizer use in the former Soviet Union fell precipitously after heavy subsidies were removed in 1988 and fertilizer prices there moved to world market levels. After 1990, the breakup of the Soviet Union and the effort of its former states to convert to market economies led to a severe economic depression in these transmission economies. The combined effect of these shifts was a four-fifths drop in fertilizer use in the former Soviet Union between 1988 and 1995. After 1995 the decline bottomed out, and increases in other countries, particularly China and India, restored growth in world fertilizer use.

When large amounts of nitrogen collect in a water body, eutrophication can result. This is an accumulation of excess nutrients which causes an algae bloom. The algae rapidly deplete all of the oxygen in the water, making it unlivable for fish and other aquatic organisms. Moreover, when crops are saturated with nitrogen, the soil can become acidified. This makes the soil inhospitable and can lead to water pollution from leaching-- the removal of elements as they are dissolved away from the soil.

Marq de Villiers, author of Water, explains the effect of pollution on water composition:

Basically, natural water is not pure but a dilute solution of elements dissolved from the earths surface, or precipitated from the air. The rain that falls to earth seeps into the soil and percolates through organic material, roots, decaying leaves, and decaying organic material (humus). As it passes, it dissolves minerals from rocks and soils, and reacts with living things, ranging from microbes and bacteria to humans. The science of groundwater can become technical, and involves process like hydrolysis, precipitation reactions, absorption and ion exchange, oxidation and reduction, gas exchanges, and biological processes such as microbial metabolism, organic productions, and respiration. Water is both a solvent and a sponge: its composition depends very largely on the environment in which it is found.

It is this absorptive nature, the fact that water derives it composition from the leaching of surface material, that makes groundwater so vulnerable to pollution. Groundwater is usually more concentrated than river water, and much harder to fix when it goes wrong.[35]

Nitrogen-based fertilizers are being added to the Earth system on a scale comparable to the largest natural flows.[36] For example, the nitrite content of fresh water is rising steadily because more and more farmers are using nitrogen-based fertilizers and there are higher levels of industrial and urban waste. Assessments though of long-term changes from nutrient load or landscape changes are complex.

Irrigation

Irrigation is the artificial application of water, from rivers, lakes, and underground aquifers, to the soil usually for assisting in growing crops.[37] Agriculture that relies on direct rainfall is referred to as rain-fed farming and in some cases both methods are used as water distribution is varied. Differences of soil and crop types also vary the amount of water needed. A main source of irrigation water is from dams.

Large dams provide water to around 30 per cent of the worlds irrigated area. Water from underground supplies most of the rest. Few countries have a full picture of their groundwater reserves, some of which lie so deep that they are inaccessible for all practical purposes. Meanwhile, pumps powered by cheap diesel and electricity are being used to extract groundwater for irrigation at a far faster rate than rainfall can renew it.[38]

Besides extracting water faster then it can be replaced "without great care and skillful management, irrigation almost inevitably causes water logging, depletion and pollution of the water supply and rising salinity in the soil. Left unchecked, these problems can eventually kill the soil altogether, explains Marq de Villiers in his book Water.[39]

For example, "elevated water tables in heavily irrigated areas of arid regions have been the leading cause of salinization"[40] as soluble salts in the earth rise with the water table. When the water evaporates, the salts are left in the soil layer. Moreover, irrigation leads to increasing concentration of toxic substances in water.

A summary sheet put out by the US Salinity Laboratory outlines the problems succinctly. Application of irrigation waters results in the addition of soluble salts such as sodium, calcium, magnesium, potassium, sulfate, and chloride dissolved from geologic materials with which the waters have been in contact. Evaporation and transpiration (plant uptake) of irrigation water eventually cause excessive amount of salt to accumulate in soils unless adequate leaching and drainage are provided. Excessive soil salinity reduces yields by lowering plant stand and growth rate. Also, excess sodium under conditions of low salinity and especially high pH can promote slaking of aggregates, swelling and dispersion of soil clays, degrading soil structure, and impeding water and root penetration. Some trace constituents, such as boron, are directly toxic to plants.[41]

Growth in irrigation facilitated a rise in fertilizer use. With enough water plants can effectively use much more fertilizer.[42] As low soil moisture limits nutrient uptake, without irrigation in arid and semiarid regions, yields would suffer. The adoption of high-yielding varieties and growing crops in drier environments have resulted in steadily rising shares of food production coming from irrigated lands.[43]

World Irrigated Area[44]

Paralleling the tenfold increase in fertilizer use during the last half of the last century was the near tripling of irrigated area.

Conclusion

Water affects soil quality and soil is part of the water cycle-- its structure has a major influence on water movement. If the water in a given ecosystem is altered significantly in quantity or quality, the hydrological cycle is affected and the ecosystem itself will change.[45] How water and soil are treated now influences their sustainability. To help increase sustainability, being more effective is important. For example, through agroecology, permaculture, organic agriculture, and increasing biodiversity.

Appendix 1: Conceptualization of Earth systems

Water Cycle[46]

Nitrogen Cycle[47]

Biospheric nitrogen cycle centered on crops[48]

Appendix 2: Grain Production

World Corn Production[49]

World Wheat Production[50]

World Rice Production[51]

Appendix 3: Fertilizer Use by Country[52]

Among the big-three grain producers, China is the leading user of fertilizer, with the United States a distant second. India is now closing the gap with the United States and may overtake it within the next several years.