TY - JOUR

T1 - Nitrogen fertilization and nitrate leaching into groundwater on arable sandy soils

AU - Köhler, Kai

AU - Duynisveld, Wilhelmus H.M.

AU - Böttcher, Jürgen

N1 - Copyright: Copyright 2008 Elsevier B.V., All rights reserved.

PY - 2006/4

Y1 - 2006/4

N2 - Nitrate leaching depending on N fertilization and different crop rotations was studied at two sites with sandy soils in N Germany between 1995 and 2000. The leaching of NO3- was calculated by using a numerical soil-water and N model and regularly measured Nmin values as input data. Also the variability of Nmin values on the sandy soils was determined along transects. They reveal the high variability of the Nmin values and show that it is not possible to confirm a significant Nmin difference between fertilizer treatments using the normal Nmin-sampling intensity. Nitrate-leaching calculations of five leaching periods showed that even strongly reduced N-fertilizer applications did not result in a substantially lower NO3- leaching into the groundwater. Strong yield reductions of even more than 50%, however, were immediately measured. Mean NO3- concentrations in the groundwater recharge are >50 mg L-1 and are mainly due to mineralization from soil organic matter. Obviously, the adjustment of the N cycle in the soil to a new equilibrium and a reduced NO3--leaching rate as a consequence of lower N inputs need a much longer time span. Catch crops are the most efficient way to reduce the NO3- concentrations in the groundwater recharge of sandy soils. Their success, however, strongly depends on the site-specific development possibilities of the catch crop. Even with all possible measures implemented, it will be almost impossible to reach NO3- concentrations <50 mg L-1 in sandy soils. The only way to realize this goal on a regional scale could be by increasing areas with lower nitrate concentrations in the groundwater recharge like grassland and forests.

AB - Nitrate leaching depending on N fertilization and different crop rotations was studied at two sites with sandy soils in N Germany between 1995 and 2000. The leaching of NO3- was calculated by using a numerical soil-water and N model and regularly measured Nmin values as input data. Also the variability of Nmin values on the sandy soils was determined along transects. They reveal the high variability of the Nmin values and show that it is not possible to confirm a significant Nmin difference between fertilizer treatments using the normal Nmin-sampling intensity. Nitrate-leaching calculations of five leaching periods showed that even strongly reduced N-fertilizer applications did not result in a substantially lower NO3- leaching into the groundwater. Strong yield reductions of even more than 50%, however, were immediately measured. Mean NO3- concentrations in the groundwater recharge are >50 mg L-1 and are mainly due to mineralization from soil organic matter. Obviously, the adjustment of the N cycle in the soil to a new equilibrium and a reduced NO3--leaching rate as a consequence of lower N inputs need a much longer time span. Catch crops are the most efficient way to reduce the NO3- concentrations in the groundwater recharge of sandy soils. Their success, however, strongly depends on the site-specific development possibilities of the catch crop. Even with all possible measures implemented, it will be almost impossible to reach NO3- concentrations <50 mg L-1 in sandy soils. The only way to realize this goal on a regional scale could be by increasing areas with lower nitrate concentrations in the groundwater recharge like grassland and forests.

KW - Catch crops

KW - N fertilization

KW - Nitrate concentrations

KW - Nitrate leaching

KW - Soil N

UR - http://www.scopus.com/inward/record.url?scp=33645986477&partnerID=8YFLogxK

U2 - 10.1002/jpln.200521765

DO - 10.1002/jpln.200521765

M3 - Article

AN - SCOPUS:33645986477

VL - 169

SP - 185

EP - 195

JO - Journal of Plant Nutrition and Soil Science

JF - Journal of Plant Nutrition and Soil Science

SN - 1436-8730

IS - 2

ER -