vs. C4 ), age of SOM, depth in the profile, and the amount of fossil fuel derived CO2 in the atmosphere (Shearer Although it is estimated that salinity stress occurs in 50% of irriand Kohl, 1986). However, since plants derive all their gated agroecosystems around the world, not much is known about its impact on C and N dynamics. This study was conducted to characC from the air, modeling 13C con...

allelopathy is one of the valuable tools in weed management that recently is considered in sustainable agriculture and reduces herbicide rate challenges. in order to study the allelopathic effects of rye (secale cereal l.) on six weed spices seeds including milk thistle (silybum marianum l.) gaertn, wimmer ryegrass (lolium rigidum gaudin), lesser canarygrass (phalaris minor retz.), charlock mus...

The ability of an introduced species to thrive is often influenced by its capacity to cope with disturbance and resource fluctuation, and one way to cope is by being phenotypically plastic. The biomass and resource allocation of the invasive plant species, Phalaris arundinacea (reed canarygrass), to contrasting levels of light, soil-N and moisture was evaluated. We predicted that P. arundinacea...

BACKGROUND Plants depend on their root systems to acquire the water and nutrients necessary for their survival in nature, and for their yield and nutritional quality in agriculture. Root systems are complex and a variety of root phenes have been identified as contributors to adaptation to soils with low fertility and aluminium (Al) toxicity. Phenotypic characterization of root adaptations to in...

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BACKGROUND AND AIMS The study of rapid evolution in invasive species has highlighted the fundamental role played by founder events, emergence of genetic novelties through recombination and rapid response to new selective pressures. However, whether rapid adaptation of introduced species can be driven by punctual changes in genome organization has received little attention. In plants, variation ...

Although cool-season grasses increase DM yield at high N rates, N recovery (kg plant N kg 1 N applied) Nitrogen removal by cool-season grasses may aid in capturing exgenerally declines as N rate increases. Ramage et al. cess N from animal confinement operations or phytoremediation. (1958) reported fertilizer N recovery of 0.59 and 0.59 kg Limited information exists on the N dynamics of these gr...

Published in Agron. J. 103:509–519 (2011) Published online 7 Feb 2011 doi:10.2134/agronj2010.0360 Copyright © 2011 by the American Society of Agronomy, 5585 Guilford Road, Madison, WI 53711. All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retr...

background and objectives. integrated weed management approaches can help to decline costs weed control and improve its condition. critical period of weed control (cpwc) is defined as the best time for weeding. if cpwc is recognized we can accurately use herbicides and prevent environmental pollutions. beginning and duration of cpwc despond on some agents such as crop and weed traits, environme...

Intake of animals grazing grass pasture is in part infl uenced by canopy density. Our objective was to determine the vertical distribution of dry matter and neutral detergent fi ber (NDF) within temperate perennial grass swards. The study was conducted in 2004 and 2005 on a Plano silt loam (fi ne-silty, mixed, superactive, mesic Typic Argiudolls). When leaf height of each grass reached 25 cm in...