Earthworms, soil mineral nitrogen and forage production in grass-based hayfields

• Published in: Soil biology & biochemistry Vol. 40; no. 4; pp. 1004 - 1010
• Main Authors: Eriksen-Hamel, Nikita S., Whalen, Joann K.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.04.2008; New York, NY Elsevier Science
• Subjects: Agronomy. Soil science and plant productions; Biochemistry and biology; Biological and medical sciences; Carbaryl; Chemical, physicochemical, biochemical and biological properties; crop yield; Earthworm activity; earthworms; fertilizer requirements; Forage; forage crops; forage grasses; Fundamental and applied biological sciences. Psychology; grasslands; Manipulation experiment; mineralization; nitrogen; Nitrogen mineralization; nutrient uptake; Physics, chemistry, biochemistry and biology of agricultural and forest soils; plant nutrition; population dynamics; Population reduction; regression analysis; soil fertility; Soil science; Zoology (interactions between soil fauna and agricultural or forest soils); Quebec; Nitrogen mineralization; Forage; Carbaryl; Population reduction; Earthworm activity; Manipulation experiment; Monocotyledones; Insecticide; Oligochaeta; Earthworm; Gramineae; Mineralization; Angiospermae; Population; Soil science; Plant production; Hayfield; Fauna; Pesticides; Annelida; Soils; Animal activity; Carbaryl (pesticide); Inorganic nitrogen; Macrofauna; Spermatophyta; Fodder crop; Invertebrata; Carbamate
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/j.soilbio.2007.11.013

This study was designed to address how earthworm activity influences soil mineral nitrogen (N), plant N uptake and forage yield in grass-based hayfields. Earthworm populations were reduced by applying carbaryl pesticide to the experimental field plots every 2-weeks, effectively eliminating the earthworms for up to 12-weeks from May to August. Grass yields and tissue N concentrations were measured every 2 weeks, and the soil mineral N concentration determined at the final harvest. Reducing earthworm populations for up to 12-weeks did not affect grass yield or N uptake. However, regression analysis showed that plots with undisturbed earthworm populations had higher soil N by 0.8 kg N ha −1 per week, representing mineralization of about 10 kg N ha −1 during the 12-week study. This was a fraction of the fertilizer N recommendation (75 kg N ha −1) for grass-based hayfields in this region. Therefore, the increase in soil mineral N from earthworm activity was small, relative to the N requirements of the hayfield.