Friday, March 5, 2010

Chapter 29: Environmental, Energetic, and Economic Comparisons of Organic and Conventional Farming Systems

As you can guess from the sections title this chapter compares conventional farming practices with organic ones. The author behind the material for this chapter is a David Pimentel, who will be "introduced" in the ever present opening paragraph of the chapter.

As well all know farming was once only organic, all natural. Yet as population and demand for food grew we turned to chemical to produce higher yields of crops yet this bonus comes with pollution, resistance to pesticides in insects and toxins that can harm and kill animal populations. While the argument that organic farming is healthier and better for the environment is true, it is debatable as to whether organic farming can support the needs of a world of 6 billion people. David Pimentel is a professor in Cornell University's College of Agriculture and Life Sciences and long interested in the issue of sustainable agriculture. In the chapter he and his colleagues explain their conclusions that organic farming techniques have clear benefits and crop yields per hectare and the farmer's profit can be as great or greater than those of conventional agriculture". They also claim that while organic farming may not be able to replace conventional farming its techniques can make conventional methods "more sustainable and ecologically sound".

the key concept of this chapter is: the sustainability of organic farming techniques.

The first section bears no title and give an overview of conventional farming practices. One fact is that "more than 90% of US corn farmers rely on herbicides for weed control, and one of the most widely used of those herbicides, atrazine, is also one of the most commonly found pesticides in streams and groundwater." It is estimated that $12 billion is the environmental health care cost for using pesticides as recommended levels in the US. Runoff has also been associated with the deterioration of large fisheries in North America as well as nitrogen fertilizer from the Corn Belt contributing to the "dead zone" in the Gulf Of Mexico. Reports from the National Research Council (NRC) state that "the cost of excessive fertilizer use - that is, fertilizer inputs that exceed the amount crops can use - is $2.5 billion per year." Annual costs for public and environmental health losses due to soil erosion were estimated to exceed $45 billion.

One suggested solution to this in Integrated pest and nutrient management systems along with certified agriculture. These two combined can "reduce reliance on agrochemical inputs as well as as make agriculture environmentally and economically sound." Various government programs in Canada, Sweden and Indonesia have shown that it is possible to meet a 50-65% reduction i pesticide use without crop yields and quality.

Organic agriculture is aimed at augmenting ecological processes to foster plant nutrition while conserving soil and water resources. This system eliminates the need and use of agrochemicals as well as reduce other external inputs, thus improving the environment and farm economics. The National Organic Program "codifies organic production methods that are based on certified practices that are verified by independent third party viewers." This is to help give consumers assurance on the methods involved in the making of their food and allow them to choose foods based off production methods. Essentially, it educates the masses and gives them freedom of choice, not bad at all.

Organic culture is growing fast in the agricultural section of the United States. Dimitri and Greene have reported the doubling of organic production area from 1992 to 1997 and is currently more than 500,000 hectares. Organic food also has annual sales of of more than $7 billion and are growing at double digit rates.

The next section titled The Rodale Institute Farming System Trial (FST) describes a comparison by the FST of several types of farming methods over a 22 year study. The study covered sustainability, environmental impacts and other performance criteria. The first method was Conventional cropping which was based upon synthetic fertilizer and and herbicide use and used a simple 5 year crop rotation between corn, corn, soybeans, corn, soybeans. All fertilizer and herbicide use followed Pennsylvania State University Cooperative Extension recommendations. Crop residue was left on the surface to conserve soil and water resources. This system had no more exposed soil then the organic method but did not have cover crops during the non-growing season. Second was Organic Animal-Based cropping. Grain crops were grown to for animal feed, not sale. the rotation was more complex and included corn, soybeans, corn silage, wheat and red clover-alfalfa hay and a rye cover crop before corn silage and soybeans. Manure from cattle was applied at a rate of 5.6 metric tons per day, 2 years out of every 5, before plowing for corn. Extra Nitrogen was added through legume-hay crops and the total nitrogen was 40 kilograms per year. No herbicides or weed control were used. mechanical cultivation, weed suppressing crop rotations and relay cropping were instead used, in which one crop was a living mulch for another. Awesome recycling. The third method was Organic Legume based cropping and represented a cash grain operation without livestock. Nitrogen-fixing green manure crops provided nitrogen rather than chemicals. Final crop rotation included hairy vetch (a winter cover crop used as green manure), corn, rye (winter cover crop), soybeans and winter wheat. The initial five year system was modified twice to improve rotation. Total nitrogen added was 49 kg per ha per year.

The results showed that (from 1981 to 1985) under normal rainfall soy bean yields were similar for all three methods, corn yield were significantly higher than the organic systems to begin with but the organic systems caught up after 1985. Under drought conditions (1988 to 1998 with 5 years being drought years) with less than 350mm of rain compared to the regular 500mm, average corn yields were 28-34% higher in the two organic systems while the conventional system yielded less. Even soy bean yield was higher in the organic systems as compared to the conventional one. This was brought about by the higher amounts of water in the soils of the organic fields and the lower amounts in the conventional field.

In the Discussion section states that the management of the soil in the animal, legume, and conventional systems lead to nitrogen increases of 27.9%, 15.1% and 8.6% respectively. 41% other the volume of organic matter in the organic systems was water as compared to the 35% in the organic matter of the conventional system. Increased soil biodiversity was higher in the organic systems which is why they had better yields, to put it shortly. As the organic methods used far less fossil fuel energy to produce crops they were all around better for the environment as less CO2 was being pumped inti the atmosphere.

Crop Yields and Economics is a huge section and since this post is very long I will cut to the chase. In most cases when compared to the rest of the world, the experiment say a more even yield of crop between the organic and conventional methods yet the real world comparison showed the organic methods trail by 30-50% in yield (in Europe) to conventional methods. Organic crops also cost more in the store than conventional. Some challenges for organic agriculture are nitrogen deficiency and weed competition. While in the experiment they are able to overcome this with legume crops others have found it more difficult. This can be due to geographical variances between farming regions. Mechanical weed control is also mostly effective under dry conditions, so wetter areas will have trouble. Pest control is the largest threat as nothing really compare to pesticides for effectiveness.

There are four organic technologies that if adopted, would most likely be beneficial: 1. employing off-season cover crops (why not have your soil ready to be used immediately next growing season?) 2. use more extended crop rotations to help conserve water, educe insects, and weeds (geographical situation not withstanding) 3. increase level of soil organic matter which helps conserve water and mitigates drought effects. 4. employing natural biodiversity to reduce or eliminate use of chemicals (Mother nature knows best so work with her, not against).

Conclusions is just as it sounds, the end summary. Here are listed some benefits of organic technology identified in the experiment:
- Soil organic matter and nitrogen were higher in organic systems providing benefits to the sustainability of organic agriculture.
- Higher levels of organic matter helped conserve soil and water resources which was useful during droughts.
- Since organic crops bring higher market prices the net economic return is often equal to or higher than conventional crops.
- Recycling of livestock waste reduces pollution whilst benefiting the organic culture.

All in all I see why organic farming is still seen as viable today despite the success of conventional methods. Natural methods in the long run are better as they do not alter the state of the land and crops and reduces pollution and contamination via chemicals. I hope we can find a balance between organic and conventional methods so as to ease the burden on farmers to supply our expanding population with much needed food.

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