Tuesday, November 6, 2007 - 3:45 PM
147-7

N Release from a Nitrogen 15 Labeled Cover Crop in Relation to Soil Fauna Activities between No-till and Conventional Tilled Upland Rice Production.

Masakazu Komatsuzaki1, Rika Kusumoto1, Chiharu Okiba1, Naomi Asaki2, Hideto Ueno3, Masaaki Araki4, Hajime Araki5, and Shoji Matsumura6. (1) Ibaraki University, 320-1 Asahi-Cho Tomobe-Machi, Nishiibaraki-Gun, Ibaraki, 309-1717, JAPAN, (2) Ehime University, Ehime, Japan, (3) University Farm, Ehime University, Matsuyama Ehime, 799-2424, Japan, (4) National Institute for Agro-Environmental Science, Ibaraki, Japan, (5) Field Center for Northern Biosphere, Hokkaido University, Sapporo, 060-0811, Japan, (6) Field science center, Tokyo university of agriculture and technology, Tokyo, Japan

Cover crops and no-tillage practices may be effective tools for ensuring sustainable agriculture and eco-system service; because these soil management strategies increase soil organic matter and improve soil biological diversities and activities in intensively managed summer field cropping system.However, there are little information on contribution of soil fauna activities to establish optimum N management in between no-till and rotary tilled fields. Using a 15N tracer method, we examined the influence of tillage treatments ( no-till and rotary) on cover crop residue decompose rate,  15N distribution in each soil fauna and 15N uptake by field rice growths. The results suggested that a doubling of cover crop N contribution to the subsequent crop was observed in no-till with cover crop treatment compare with in rotary with fallow. Especially, earth warms in no-till significantly contributed to decompose of cover crop residues. A combined with no-tillage system with cover cropping will be a new soil management strategy in Japan, because they can scavenge soil residual nitrogen , improve carbon balance and their ecological functions can be utilized to establish an optimal nitrogen cycle.

Back to Rice, Wheat and Barley: I/Div. A06 Business Meeting
Back to A06 International Agronomy

Back to The ASA-CSSA-SSSA International Annual Meetings (November 4-8, 2007)