Nitrogen Dynamics and Wheat Yield in a No-Till Organic Green Manure System Using the Roller Crimper

Iris Vaisman, Martin Entz, Rob Gulden and Don Flaten

Abstract
Use of the roller crimper presents organic farmers with the opportunity to reduce tillage in green manure years. This study investigated the effects of no-till green manure management on soil conservation, wheat yield, and green manure nitrogen utilization.

The study was conducted on organically managed land at the Carman Research Station, Manitoba and on a certified organic farm near Oxbow, Saskatchewan. In the spring, a pea (Pisum sativum L.) and oat (Avena sativa L.) intercrop was seeded as a green manure. Beginning at pea flowering, the green manure was terminated by rolling, tilling, or a combination of the two. In the following spring, Hard Red Spring Wheat (cv. 5602) (Triticum aestivum L.) was seeded into the plots. Soil cover measurements were taken before seeding the wheat. Soil nitrogen and wheat biomass were sampled at stem elongation, anthesis, and soft dough.

Results showed that eliminating tillage in the green manure year a) increased soil cover in spring, b) reduced the rate of nitrogen release, and c) reduced wheat yield in two out of three site years. No till green manure management can therefore provide benefits of soil conservation but may result in decreased wheat yield.


Source
Proceedings of the Joint Conference of the Canadian Society of Soil Science and the Canadian Society of Agronomy, Beyond Organics session. Saskatoon, Saskatchewan. 20-24 June 2010.


Author Locations and Affiliations
Department of Soil Science, University of Manitoba


Posted July 2010