May 19, 2015
This blog post was originally published by the Organic Farming Research Foundation, an NSAC member organization. We reprint it here with permission.
A newly-published study comparing organically-managed and conventional farmland in New Zealand found that organic fields consistently provide more value per acre in the production of beans, peas, barley and wheat.
The study, authored by Harpinder Sandhu, Ph.D., and a team of scientists from Australia, New Zealand, England, Denmark and the U.S., calculated and compared the value of both “non-traded ecosystem services” and the market value of crops produced on matched pairs of ten organic and ten conventional farm fields.
The scientists found that organic production methods provided more value using either approach.
“Ecosystem services are the inputs that nature provides,” said Diana Jerkins, Ph.D., research director for OFRF. “In agriculture we don’t usually calculate the value of ecosystem services. But in this analysis, the value of ecosystem services can be compared to the value of a conventional input.”
The Sandhu study assessed two ecosystem services: biological pest control versus conventional pesticide applications, and the nitrogen produced by microbial action versus applications of conventional fertilizers.
The organic systems used fewer external inputs, such as chemical fertilizers and pesticides, under both scenarios.
Compared to conventional yields, organic ones were lower for barley and wheat but similar for beans and peas. However, lower yields in barley and wheat were compensated by higher market prices for organically produced grains.
Biological control is one method of pest management frequently used on organic farms that relies on natural mechanisms, such as predation of problem pests by other organisms, rather than chemical pesticide application. The study found that predation rate of aphids and blowfly eggs was significantly higher in organic fields. Due to the extremely low predation rate in the conventional fields, none of these fields had any economic value for biological control.
There was no significant difference between organic and conventional fields for mineralization rates (i.e. the rate at which nitrogen becomes available to plants), but the range in economic value was higher in the organic systems with a mean value of $230 per hectare per year compared to $157 per hectare per year for conventional.
The combined economic values for the two ecosystem services (biological control and microbial nitrogen production) were greater for the organic system in all four crop types, ranging from $178-528 per hectare per year for organic systems and $60-244 per hectare per year for conventional.
When calculating the combined economic value for each crop, which includes the market value of the crop as well as the non-market value of the two ecosystem services, the study found that organic production systems resulted in significantly higher value per crop. The total economic value ranged from $1,750-4,536 per hectare per year in the organic fields and $1,585-2,560 per hectare per year in the conventional fields.
Why is this research important?
As agricultural intensification becomes more prevalent across the globe in order to provide a sufficient food supply, a future challenge is to understand the value of ecosystem services, and the environmental consequences of intensification.
To better understand the potential value of the two ecosystem services studied, the New Zealand farm studies were extrapolated to temperate arable areas in 15 global regions. Total nitrogen consumed and total pesticide use was also determined in those regions.
This extrapolation resulted in very high potential economic values of ecosystem services for an organic scenario. The value of these two ecosystem services was more than the total direct costs of pesticides and fertilizers in the 15 regions studied. In the long term, ecosystem services enhancement will help to optimize production and sustainability of farms.