Annual medics and berseem clover as emergency forages or green manure for canola

مرکز و کتابخانه مطالعات اسلامی به زبان های اروپایی

منو

" Annual medics and berseem clover as emergency forages or green manure for canola "
A. Shrestha

Document Type	:	Latin Dissertation
Language of Document	:	English
Record Number	:	1113414
Doc. No	:	TLpq304251162
Main Entry	:	A. Shrestha
Title & Author	:	Annual medics and berseem clover as emergency forages or green manure for canola\ A. Shrestha
College	:	Michigan State University
Date	:	1996
student score	:	1996
Degree	:	Ph.D.
Page No	:	81
Abstract	:	Development of cropping systems which provide quality emergency forages and reduce the need for chemical fertilizer nitrogen (N) in a subsequent non-legume crop may benefit farmers. This study evaluated the forage dry matter (DM) yield and quality of three annual medic species (barrel medic (Medicago truncatula Gaertn. 'Mogul'), burr medic (M. polymorpha L. 'Santiago'), and snail medic (M. scutellata L. 'Sava')), and berseem clover (Trifolium alexandrinum L.); quantified N accumulated at plowdown by these species; evaluated N fertilizer replacement value (FRV) of legumes on a subsequent canola (Brassica napus L.) crop; and compared the response of canola to fertilizer N under various cropping systems. The annual medics, berseem clover, alfalfa (M. sativa L.), and spring canola were seeded in early May. All the alfalfa, spring canola, and some annual medic and berseem clover plots were harvested at 60 days after planting (DAP), while some of the annual medic and berseem clover plots were grown as green manure for 90 days. All plots were moldboard plowed 90 DAP and winter canola 'Ceres' was planted in mid-August. Plots were split into 4 sub-plots and fertilizer N was applied in March at rates of 0, 50, 100, and 150 kg N ha. Annual medics and berseem clover produced similar or higher yields than did alfalfa when harvested at 60 DAP. Annual medic regrowth (except Mogul) was less than regrowth of alfalfa or berseem clover and contained mostly residue and seed pods. The medics generally had similar crude protein but higher acid detergent and neutral detergent fiber concentrations than did alfalfa at 60 DAP. Berseem clover produced DM yield and forage quality comparable to alfalfa at 60 DAP and 90 DAP. Legumes had little effect on yield of the subsequent canola. Canola responded to added levels of fertilizer N and no interactions were observed between the cropping system and N treatments. Harvesting the legume at 60 DAP and plowing down the regrowth at 90 DAP or plowing down the unharvested legume at 90 DAP produced similar canola grain yields. The amount of above-ground biomass or N content at plowdown was not significantly correlated with canola yield. Fertilizer replacement value of legumes were non-estimable due to lack of significant differences in the yield of canola following a non-legume or a legume at the 0 N level. Among the annual legumes tested, berseem clover has the most potential as an emergency forage.
Subject	:	Biological sciences
	:	Brassica napus
	:	Medicago polymorpha
	:	Medicago scutellata
	:	Medicago truncatula
	:	Trifolium alexandrinum