Blog 4- Environmental, Energetic, and Economic Comparisons of Organic and Conventional Farming Systems

There was a time when all farming was organic. Fertilizer was compost or manure, fields were left fallowed to recover soil, crops were rotated, and pesticides were nonexistant. The alternatives to these is usually called organic farming. Organic farming techniques is related to sustainable development.

Heavy reliance on synthetic chemical fertilizers and pesticides is having serious impacts on public health and the environment. Herbicides are used by 90% of US corn farmers. Nutrient loading is associated with deterioration of fisheries and the overall health of lakes and oceans. It is modern agricultural practices that contribute to erosion of soil, environmental and human health. We need to reduce our reliance on agro-chemical inputs; Canada and Sweden hace demonstrated that our use can be reduced by 50% to 65%.

The aim of organic agriculture is to augment ecological processes that foster plant nutrition yet conserve soil and water resources. Organic agriculture is a fast-growing agricultural section in the United States. Organic food sales total more than $7 billion per year, therefore the outlook for organic production is bright. The developing agricultural policies are more in tune with the environment while increasing energy efficiency and economic returns.

The Rodale Institute Farming Systems Trial in Pennsylvania, on 6.1 hector has three subplots that are large enough that farm-scale equipment could be used for operations and harvesting.

Conventional Cropping is based on synthetic fertilizer and herbicide use, represents a typical cash grain, row crop farming unit and used a simple 5-year crop rotation that reflects operations in the region.

Organic animal-based cropping grew grain crops that were grown for animal feed, not cash sale. Aged cattle manure was used as a nitrogen source every 2 years out of every 5. The system did not use herbicides for weed control; it relied instead on mechanical cultivation, weed suppressing crop rotations, and relay cropping.

Organic Legume-based cropping system represented a cash grain operation, without livestock. It used no synthetic fertilizers, relying instead on green manure. It also did not use herbicides for weed control.

Crop yields under normal rainfall were similar for all systems.

Crop yields under drought conditions average yields in 5 dry years were significantly higher in the two organic systems. During the extreme droughts organic animal system it had significantly higher corn yields. The measurements showed significantly more water in the soil farmed using the organic legume system than in the conventional system. This accounted for the higher soybean yields in the organic legume system in 1999.

Discussions came to a conclusion that crop yields and economics of organic farming appear to vary based on the crops, regions, and technologies studies. There wwere large amounts of soil organic matter in the organic systems that aided in the tolerance of droughts.

Oil and natural gas inputs In general, the use of less fossil energy by organic agricultural systems reduces the amount of carbon dioxide released to the atmosphere, and therefore the problem of global climate change.

Crop yields Soybeans, and wheat yields were similar in all three systems. There is a higher gross income for conventional than the organic alternative system. The lower yields in organic farming is caused by lower nitrogen-nutrient inputs. In New Zealand, wheat yields are 38% lower than those in the conventional system, but these can be eliminated by raising soil nitrogen throught the use of animal manure or legume cropping systems.
There is a higher gross income for conventional than for the organic however market price for organic food such as corn and soybeans is higher.
Challenges for organic agriculture the two primary problems were nitrogen deficiency and weed competition. The Mechanical weed control is usually more effective than chemical weed control under dry conditions, while the reverse is true under the wet conditions.
Adoptions of organic technologies include 1) off season cover crops 2) extended crop rotation 3) increase level of soil organic matter 4) allow natural biodiversity.
Benefits of Organic Technologies

• soil organic matter were higher
• high levels of soil organic matter serve soil and water prove beneficial during droughts
• fossil energy inputs 30% lower
• labor inputs are evenly distributed over the year
• crop rotation and cover cropping reduce soil erosion, pest problems, and pesticides use
• recycling of livestock waste reduces pollution and benefits organic agriculture
• abundant biomass increases biodiversity