Agriculture Reference
In-Depth Information
a limited part being derived from peat mineralization and with small losses to the
environment (Sonneveld and Lantinga 2011). The example of this pioneering farmer
acted as a “lighthouse,” inspiring other farmers and scientists. Procedures resulted
in the formation of an anthropogenic A horizon in these Histosols, which may be
regarded as a separate phenoform. Soil security has improved following this form
of innovative management that had a positive effect on several ecosystem functions.
Ecosystem services 1 and 3 have improved. Reducing the N surplus has reduced N
flow into surface waters and has thus improved service 2. The landscape in which
this particular farm is located is the National Landscape “Green Hart” of Holland,
which is highly valued for its historic reclamation patterns and dominance of dairy
farming. Maintaining farming in this area, which is enhanced by the described inno-
vative new approach to management, contributes to services 4 and 7. Yet, a continu-
ous problem is land subsidence because of drainage, resulting in net carbon loss,
giving problems with ecosystem service 6 although the organic matter content of
surface soil has increased following innovative management.
2.3.6 g
leyic
P
odZolS
in
the
n
etherlandS
Gleyic Podzols are the most common sandy soils in the Netherlands. The official fer-
tilizer recommendations for these soils were relatively high at the end of the 1980s,
up to 400 kg N/ha per year. They decreased thereafter; however, a group of 100
dairy farmers in the National Landscape Northern Frisian Woodlands reported in
1995 an average N fertilizer use of 290 kg N/ha, ranging from 150 to 478 kg N/ha
(Verhoeven et al. 2003). As a result, N surpluses at farm level ranged from 162 kg
N/ha per year to 560 kg N/ha per year, with a mean farm N surplus of 326 kg N/ha
per year. These high environmental losses resulted in a poor environmental quality,
for example, reflected in high levels of nitrate in the upper groundwater (Sonneveld
and Bouma 2003).
Ecosystem services 2 and 3 were not satisfied and services 4 and 7 were threat-
ened because rationalization of dairy farming called for large fields and cutting
hedgerows, which are considered to be a key quality of the landscape. Concerned
farmers organized into an environmental cooperative to improve conditions, taking
a proactive approach that also attracted researchers. Thus, a “lighthouse” was cre-
ated that has received continued national and international attention. An intensive
participatory research program from 1997 to 2003, focused on increasing nutrient
use efficiencies, resulted in a reduction of fertilizer input to 136 kg N/ha per year
in 2001/2002 and a corresponding decrease of N surpluses to 172 kg N/ha on aver-
age. More emphasis was placed on organic manuring. Farm N uptake efficiencies
increased from 21% in 1997/1998 to 33% in 2001/2002, and organic matter contents
of surface soils increased significantly forming a recognizable phenoform: old grass-
land (Sonneveld et al. 2002). In addition, this study defined two other phenoforms
of the genoform Gleyic Podzols: reseeded grassland and continuous maize cropping.
After studying 40 fields on different farms, these forms of management could be
related to soil C contents:
%C = 3.40 − (1.54 × Maize) + (0.19 × Old) + (0.55 × GWC)(
r
2
= 0.75)
