Zusammenfassung der Ressource
Nitrogen
- assess SNS
- comprises of...
- SMN
- Soil Mineral Nitrogen
- can vary by 50% across a field
- 15-20samples per 10ha
- need to
maintain
field heat
- get to lab asap
- assure lab is accredited,
worthwhile and specific
- SMN increases
during storage
- 2.5kg/ha/day
- keep cool if stored
freezing increases SMN
- N in crop
- N mineralised from
soil OM/crop debris
- can predict from...
- previous crop
- potatoes high N
sugar beet low
- soil type
- sands retain least N
silts retain most
- potential
leaching
- ALL PREDICTION
- after ploughing
out grass
- releases
a lot of N
- allow for N in manures
- urine/dung patches
- causes hotspots
- urea converts to ammonia
- affected by
heat and acidity
- high pH
- excess N causes lodging
- SNS high in north west,
SNS med in north east,
SNS low in east
- can sample in
winter or spring
- except...
- light soils
- shallow soils
- high winter rainfall
- 0-60cm in winter
- less likely to overestimate
- 0-90cm in spring
- HGCA