『Abstract
Amendments with the potential to reduce phosphorus (P) losses
from agricultural grassland arising from the land application
of dairy-soiled water (DSW) were investigated. Optimal application
rates were studied, and associated costs and feasibility were
estimated. First, batch tests were carried out to identify appropriate
chemicals or phosphorus sorbing materials to control P in runoff
from DSW. Then, the best four treatments were examined in an agitator
test. In this test, soil - placed in a beaker - was loaded with
DSW or amended DSW at a rate equivalent to 5 mm ha-1
( the maximum permissible application rate of DSW allowable in
a 42-day period in Ireland). The soil was overlain with continuously
stirred water to simulate runoff on land-applied DSW. Optimum
application rates were selected based on percentage removal of
dissolved reactive phosphorus in over』lying water and the estimated
cost of amendment. The costs of the amendments, per cubic metre
of DSW, increased in the order: bottom ash (1.55 C（＝が重なる：ユーロ、Euro
sign）), alum (1.67 to 1.92 Euro), FeCl2・4H2O (3.55 to 8.15 Euro), and lime (20.31 to 88.65
Euro). The feasibility of the amendments, taking into account
their cost, potential adverse effects, public perception, and
their performance, decreased in the order: alum＞FeCl2・4H2O＞bottom ash＞lime. Amendments to DSW could be
introduced in critical source areas - areas where high soil test
P and direct migration pathways to a receptor overlap.
Keywords: Dairy-soiled water; Iron (II) chloride tetrahydrite;
Lime; Alum; Bottom ash
1. Introduction
1.1. Amendments to sequester P
2. Materials and methods
2.1. Soil preparation and analysis
2.2. DSW sampling and analysis
2.3. Classification and determination of suitable amendments
for use in the agitator test
2.4. Agitator test
2.5. Water sampling and analysis
2.6. Statistical analysis
2.7. Cost analysis
3. Results
3.1. DSW and amendment analysis
3.2. Agitator test
3.3. Statistical analysis
3.4. Cost and feasibility analysis
4. Discussion
5. Conclusions
Acknowledgements
References