|
|
||||||||
Department of Land Resource Science, Univ. of Guelph, Guelph, ON, Canada N1G 2W1.
* Corresponding author.
ABSTRACT
Cover crops, although they may reduce the leaching of NO3-N to groundwater, may increase nutrient concentration in runoff because of biomass leaching during rainfall events. A simulated rainfall study was conducted in the laboratory to determine the effects of freezing alone and freezing plus drying treatments, loading rate, and rainfall intensity on the leaching of NH4-N, NO3-N, and inorganic P from the biomass of red clover (Trifolium pratense L.), annual ryegrass (Lolium multiflorum L.), and oilseed radish [Raphanus sativus (L.) var. oleifera Dc Metzg]. Concentration of P increased during early stages of leaching, then decreased slowly but remained greater than 50% of the maximum, even after the equivalent of 6.0 cm of simulated rainfall. Concentrations of NO3-N were similar to P but changed less during leaching. Weighted mean concentrations of P ranged from less than 2.0 to more than 15 mg L–1. Concentrations were greatest with oilseed radish and least with red clover. Drying the sample in addition to freezing increased the P concentration, particularly in the initial leaching. About 30% of the biomass P was leached from oilseed radish and annual ryegrass, but only about 20% from red clover. Because oilseed radish had a greater biomass P concentration, the total P leached was much greater than for the other two species. Between 5 and 9% of the biomass N was leached as either NO3-N or NH4-N from ryegrass and red clover while over 10% was leached from oilseed radish. The results indicate that cover crop species differed markedly in their potential impact on nutrient concentration, particularly P, in runoff. Of the three cover crops tested, oilseed radish has the greatest potential impact and red clover the least.
Contribution from Dep. of Land Resource Science, Univ. of Guelph.
Received for publication February 4, 1993.
This article has been cited by other articles:
![]() |
I. Sturite, T. M. Henriksen, and T. A. Breland Longevity of White Clover (Trifolium repens) Leaves, Stolons and Roots, and Consequences for Nitrogen Dynamics under Northern Temperate Climatic Conditions Ann. Bot., July 1, 2007; 100(1): 33 - 40. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Torstensson, H. Aronsson, and L. Bergstrom Nutrient Use Efficiencies and Leaching of Organic and Conventional Cropping Systems in Sweden Agron. J., April 11, 2006; 98(3): 603 - 615. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. F. Bergstrom and F. Djodjic Soil as an important interface between agricultural activities and groundwater: leaching of nutrients and pesticides in the vadose zone Geological Society, London, Special Publications, January 1, 2006; 266(1): 45 - 52. [Abstract] [PDF] |
||||
![]() |
M. E. Bechmann, P. J. A. Kleinman, A. N. Sharpley, and L. S. Saporito Freeze-Thaw Effects on Phosphorus Loss in Runoff from Manured and Catch-Cropped Soils J. Environ. Qual., November 7, 2005; 34(6): 2301 - 2309. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| The SCI Journals | Agronomy Journal | Crop Science | |||
| Journal of Natural Resources and Life Sciences Education |
Vadose Zone Journal | ||||
| Soil Science Society of America Journal | Journal of Plant Registrations | The Plant Genome | |||