Dutch practice for application of slurry in the field Herman van Schooten

Dutch legislation Application on grassland and arable land Efficiency and costs Some new developments Conclusions Introduction

Dutch legislation for slurry application Based on reduction of: - Evironmental acidification - Nutrients leaching into the environment

Dutch legislation for slurry application Emission-reducing techniques must be used  Grassland in bands on the ground - max. width 5 cm - min. distance 15 cm  Arable land bare soil - incorporation overgrown soil – see grassland Limited application period september – february (Clay arable land 2007: november – february) Limited use of organic manure :250/170 kg N from organic manure

Application on grassland Technique Slurry distribution NH3 reduction (%) Tine injection Shallow injection/ closed slits Band spreading by trailing feet > 95 > Shallow injection/ open slits

Application on grassland Tine injection and shallow injection with closed slits

Application on grassland Tine injection and shallow injection with closed slits High draught force requierd Crop damage along the slits under dry conditions Problems with obstacles

Application on grassland Technique Slurry distribution NH3 reduction (%) Tine injection Shallow injection/ closed slits Band spreading by trailing feet > 95 > Shallow injection/ open slits

Application on grassland Shallow injection with open slits Angled disc coulter or thick disc coulter

Application on grassland Shallow injection with open slits Disc (or knife) coulter followed by a vertical (injection) coulter

Application on grassland Technique Slurry distribution NH3 reduction (%) Tine injection Shallow injection/ closed slits Band spreading by trailing feet > 95 > Shallow injection/ open slits

Application on grassland Band spreading by trailing feet Ammonia emmission effected by: - height of the grass - weather conditions

Application on grassland Various application techniques - Mix of shallow injection with open slits and band spreading

Application on arable land Technique NH3 reduction (%) Tine injection > 95 Shallow injection with open slits > 80 Surface incorporation - one operation seperate operation ( until 2008 ) 35-95

Application on arable land Tine injection On bare soil before sowing

Application on arable land Surface incorporation (one and seperate operation) On bare soil – Cultivator - Disc harrow - Plough Potatoes

Application on arable land Shallow injection with open slits On bare soil In wintergrain

Efficiency index Technique Efficiency index 1) Surface spreading 25 Grassland Tine or deep injection 50 Shallow injection with open slits 50 Band spreading by trailing feet 45 Arable land Tine injection 60 Surface incorporation - one operation 55 - seperate operation Shallow injection with open slits 50 1) N-uptake of N from slurry x 100 / N-uptake of CAN-27

Costs (€/m 3 slurry) Technique Gross N-savings Net costs costs Grassland Surface spreading 1,95 - 1,95 Shallow injection/open slits 3,20 0,83 2,37 Band spreading by trailing feet 3,00 0,66 2,34 Arable land Surface spreading 1,80 - 1,80 Tine injection 2,50 1,16 1,34 Incorporation seperate operation 2,80 0,66 2,14

Some recent developments Trailing slurry hose

Some recent developments Trailing slurry hose Dilution with water: max dry matter content of the slurry: 6-7 %  better N-utilization Max. distance between storage and applicator 2,5 km (incl. second pump) Efficient system on large parcels No heavy slurry tanker; mostly used on clay ground and peaty soil Suitable for wintercrops (grain) On bare soil sometimes high draught force required

Some recent developments Slurry hose reel Combination of slurry tanker and trailing slurry hose Low draught force requierd

Some recent developments Banded slurry injection in silage maize

Some recent developments Banded slurry injection in silage maize Advantages Higher efficiency index for N and P, 25 and 100 % resp. Less operations Disadvantages Lower sowing capacity Higher risk of structure damage

Some recent developments Slurry tire Very low soil pressure < 0,5 bar Low draught force requierd Low storage capacity

Conclusions The use of injection techniques result in a significant lower ammonia emmision and a better nitrogen utilization The best application technique depends on soil type, crop type and field size Shallow injection most flexible technique Reduction of emission is mostly associated with addional costs including correction for N-savings Additional advantages in practice - Less fouling and scorching of the grass by manure - flexible application management - constant application rate

Conclusions Methods used in the Netherlands at the moment Grassland sandy soil :50 % shallow injection, 50 % band spreading clay/peaty soil : mostly band spreading by trailing feet Arable land sandy soil : Tine injection and surface incorporation before sowing : 1 % silage maize banded slurry injection clay ground : 75 % in autumn on bare soil : 20 % in spring on wintercorn (wheat) : 5 % in spring on potatoes

Thank you and Good luck ! Herman van Schooten