nitrate leaching

Bijeenkomst: EGF2015
Auteur: Albrecht K.A., Ochsner T.E., Schwab A.R. and Jokela W.E.
ISBN: 978-9090-289-61-8
Jaar van uitgifte: 2015
Producttype: Paper
Maize (Zea mays L.) silage has become an increasingly important forage crop in high output dairy farming systems in Europe and North America because of its high energy density, relatively uniform nutritive value, and efficiency of production. But due to lack of surface residue and organic matter inputs and high nitrogen (N) fertilizer inputs, maize silage production is one of the most demanding cropping systems imposed on our soil and water resources. We investigated intercropping maize with the persistent rhizomatous legume, Caucasian clover (Trifolium ambiguum M. Bieb.), as a means to provide continuous living groundcover to minimize nitrate leaching, nutrient runoff and soil erosion. Maize was sown into existing stands of Caucasian clover that had been suppressed to reduce competition, and into areas with no clover. Total nitrate-N leached was reduced by 74% relative to the control monocrop maize under intercropped maize silage. On loess soils with 8 to 15% slope, during simulated, short, heavy rainstorms, Caucasian clover intercrop reduced water runoff by 50%, soil loss by 77%, and P and N losses by 80% relative to monocrop maize. Intercropping maize with Caucasian clover can eliminate N-fertilizer inputs and greatly reduce negative environmental impacts associated with maize silage production.

Bijeenkomst: EGF2015
Auteur: Verloop J. and Hilhorst J.
ISBN: 978-9090-289-61-8
Jaar van uitgifte: 2015
Producttype: Paper
Crop rotation in which grass and maize are alternated may contribute to efficient production of feeds for dairy production. However, in particular on dry sandy soils, proper transitions from the arable into the grassland phase and vice versa are crucial to control N leaching. From 1993 to 2010 we implemented four different systems on the experimental dairy farm De Marke on the basis of a grass-grass-grass-arablearable-arable rotation scheme. Each consecutive system was implemented to solve problems of the former system. This paper presents results on how various sources of information contributed to developments of crop rotation schemes on De Marke. Fodder beet was replaced by maize as first-year arable crop to avoid storage problems associated with fodder beet. This change tended to result in higher nitrate leaching to groundwater under first- and last-year arable crops. This was solved by leaving out N fertilization in the first-year maize. Smoothing the transition of arable land into new temporary grassland resulted in a more continuous presence of vegetation during winter. However, this had no clear effect on nitrate leaching to groundwater.