TY - JOUR
T1 - Nitrate leaching and nitrogen balances for integrated willow-poultry organic systems in Denmark
AU - Manevski, Kiril
AU - Steenfeldt, Sanna
AU - Hellwing, Anne Louise Frydendahl
AU - Andersen, Heidi Mai Lis
AU - Jørgensen, Uffe
N1 - Publisher Copyright:
© 2024 Elsevier Ltd
PY - 2024/12
Y1 - 2024/12
N2 - CONTEXT: Integrating outdoor poultry production with agroforestry promotes both production and animal welfare, but very little data exist on field nitrate leaching and soil nitrogen (N) balances. OBJECTIVE: The objective of the study was to quantify the effect of feed (soybean portion was partly replaced with ‘green’ protein from refined local biomass) and stocking density (low, 6 m2 hen−1, high, 4 m2 hen−1) on nitrate leaching and soil N mass balance (inputs minus outputs) in outdoor poultry systems combined with willow and grass agroforestry on sandy soils. METHODS: The experiment was conducted in “organic” settings in Denmark on coarse sand soil cultivated with perennial grass-clover ley and short-rotation coppice with willow trees. Nitrate leaching was determined from soil nitrate concentrations measured at 1 m depth and water fluxes simulated by the process-based model Daisy for one full hydrological year involving the grazing period of spring-summer-autumn, and the winter and following spring. RESULTS AND CONCLUSIONS: Observed soil nitrate concentrations were considerably lower and less variable in the willow zone compared to the grass zone. Nitrate leaching was significantly lower in the willow (26 ± 14 kg N ha−1) compared to the grass zone (154 ± 28 kg N ha−1). At factor level, nitrate leaching was comparable and marginally lower at low- compared to high stocking density. Feed input and manure output were major N flows in the paddocks, resulting in large surface N balance of 1198–1241 kg N ha−1 at high- and 843–875 kg N ha−1 at low stocking density, the lower end in each range being for the green-protein feed. The soil N balances were 26 % lower than the surface balances and similar between feed factors, yielding 614–634 and 899–906 kg N ha−1 for low and high stocking density, respectively. SIGNIFICANCE: High spatial and temporal variability in nitrate destined for leaching from sandy soils remains challenging to control with short rotation coppiced willow in outdoor poultry paddocks on grass-clover ley. Reducing the stocking density of the hens by 33 % tightens the soil N balance for about 36 % (33–38 %), although further measures are necessary to reduce the N balance to levels environmentally suitable for agricultural soils.
AB - CONTEXT: Integrating outdoor poultry production with agroforestry promotes both production and animal welfare, but very little data exist on field nitrate leaching and soil nitrogen (N) balances. OBJECTIVE: The objective of the study was to quantify the effect of feed (soybean portion was partly replaced with ‘green’ protein from refined local biomass) and stocking density (low, 6 m2 hen−1, high, 4 m2 hen−1) on nitrate leaching and soil N mass balance (inputs minus outputs) in outdoor poultry systems combined with willow and grass agroforestry on sandy soils. METHODS: The experiment was conducted in “organic” settings in Denmark on coarse sand soil cultivated with perennial grass-clover ley and short-rotation coppice with willow trees. Nitrate leaching was determined from soil nitrate concentrations measured at 1 m depth and water fluxes simulated by the process-based model Daisy for one full hydrological year involving the grazing period of spring-summer-autumn, and the winter and following spring. RESULTS AND CONCLUSIONS: Observed soil nitrate concentrations were considerably lower and less variable in the willow zone compared to the grass zone. Nitrate leaching was significantly lower in the willow (26 ± 14 kg N ha−1) compared to the grass zone (154 ± 28 kg N ha−1). At factor level, nitrate leaching was comparable and marginally lower at low- compared to high stocking density. Feed input and manure output were major N flows in the paddocks, resulting in large surface N balance of 1198–1241 kg N ha−1 at high- and 843–875 kg N ha−1 at low stocking density, the lower end in each range being for the green-protein feed. The soil N balances were 26 % lower than the surface balances and similar between feed factors, yielding 614–634 and 899–906 kg N ha−1 for low and high stocking density, respectively. SIGNIFICANCE: High spatial and temporal variability in nitrate destined for leaching from sandy soils remains challenging to control with short rotation coppiced willow in outdoor poultry paddocks on grass-clover ley. Reducing the stocking density of the hens by 33 % tightens the soil N balance for about 36 % (33–38 %), although further measures are necessary to reduce the N balance to levels environmentally suitable for agricultural soils.
KW - Agroforestry
KW - Daisy
KW - Evapotranspiration
KW - Grass-clover
KW - Nonparametric
KW - Soil nitrate
KW - Vegetation cover
UR - http://www.scopus.com/inward/record.url?scp=85206343420&partnerID=8YFLogxK
U2 - 10.1016/j.agsy.2024.104149
DO - 10.1016/j.agsy.2024.104149
M3 - Journal article
AN - SCOPUS:85206343420
SN - 0308-521X
VL - 221
JO - Agricultural Systems
JF - Agricultural Systems
M1 - 104149
ER -