Pulses use half the non-renewable energy inputs of other crops
What’s the ‘Pulse’ impact?
- A study by Zentner et al. (2004), based on 12 years of data (1987-1998), showed that:
- Growing peas (Pisum sativum) required roughly half the energy inputs than growing spring wheat. In terms of efficiency, peas produce almost twice the amount of grain per unit of energy input than spring wheat1.
- Spring wheat grown after peas requires 8% less energy than spring wheat grown after a cereal (wheat, barley, oats, etc.)1.
- When one year of peas are included in a 4-year crop rotation, the total energy use of the entire system is reduced by 13%1.
- A life cycle analysis by the Saskatchewan Research Council (2011), shows that replacing one year of spring wheat in a four year crop rotation (canola-spring wheat-spring wheat-spring wheat) with pea or lentil, reduces the non-renewable energy use of the entire rotation by 24 and 22%, respectively. This is again due to the reduced energy requirement of the nitrogen-fixing pulses, and the reduced fertilizer requirement of the wheat grown after the pulse crop2.
- A replication of Keystone Field to Market sustainability indicators in Western Canada shows 20% improvement in the energy index for peas from 1981 to 2006 and a 33% improvement for lentils from 1986 to 20063.
||Zentner, R. P., Lafond, G. P., Derksen, D. A., Nagy, C. N., Wall, D. D., and May, W.E. 2004. Effects of tillage method and crop rotation on non-renewable energy use efficiency for a thin Black Chernozem in the Canadian Prairies. Soil & Tillage Research. 77: 125-136.
||Life Cycle and Socio-Economic Analysis of Pulse Crop Production and Pulse Grain Use in Western Canada. Saskatchewan Research Council Publication No. 12135-1E11, March 2011. (not published as of February 2012)
||Application of Sustainable Agriculture Metrics to Selected Western Canadian Field Crops. 2011. Serecon Management Consulting.
Effects of tillage method and crop rotation on non-renewable energy use efficiency for a thin Black Chernozem in the Canadian Prairies
This study compared different crop rotations and tillage practices to see how they affect non-renewable energy use. It was published in the peer-reviewed journal Soil and Tillage Research in 2004.
The experiment included three different crop rotations and three different tillage practices. The three crop rotations were: 1) monoculture wheat; 2) wheat and flax; and 3) wheat, flax and peas. Each rotation was grown with conventional, minimum, or zero tillage practices. Energy use was determined by adding all the non-renewable energy used to manufacture, package, transport, maintain, and apply all inputs (such as fertilizer, fuel, and pesticide). Energy use efficiency was measured in three different ways: 1) the amount of grain produced per unit of energy input; 2) the ratio of energy output to energy input; and 3) the net energy produced (i.e. the energy produced in the harvested crop, minus the energy required to produce it).
After 12 years, the study showed that energy use efficiency was highest for the rotation that included peas. Non-renewable energy inputs required by peas were lower than flax or wheat. The addition of both peas and flax to the wheat-based crop rotation reduced total energy use by 13% compared to the rotation that added flax only. Growing wheat after another wheat crop required 8% more energy than if wheat was grown after peas. Improved energy use efficiency was attributed to the nitrogen supplied by the pea crop, reducing the need for added nitrogen fertilizer. Energy use efficiency was also improved when minimum or zero tillage practices were used to produce rotations that included peas or flax; however, tillage practices had no effect on energy use in monoculture wheat rotations.
This study confirms that adding peas to crop rotations can increase the efficiency of energy used in agriculture on the Canadian Prairies.
Life Cycle and Socio-Economic Analysis of Pulse Crop Production and Pulse Grain Use in Western Canada
Not published as of February 2012. Link and summary to be added once available
Application of Sustainable Agriculture Metrics to Selected Western Canadian Field Crops