Download - Nitrogen in Cranberry Agriculture
UMass Cranberry Station
Carolyn DeMoranville, UMass
Nitrogen in Cranberry Agriculture
2UMass Cranberry Station
Why cranberry farmers use nitrogen Important in plant structure
and function• Protein, DNA• Chlorophyll
Each year the plant makes more leaves, stems, and roots and sheds leaves and roots
In the fruit, N is the element in the highest concentration
Nitrogen is arguably the most important fertilizer element applied to cranberries
3UMass Cranberry Station
Nutrient Removed- leaves/
stems*
Removed –
100 bbl crop
Total
Nitrogen 13.6 5.0 18.6
N removed (pounds/acre per year) - Early Black
*Leaves and stems are removed as part of harvest operations
Since Early Black has small leaves and thin stems compared to hybrids, there is an assumption that N removal for those would be greater. This calculation does not include N in roots.
4UMass Cranberry Station
How much N is required?
At least enough to replace what’s lost and to support new growth and fruiting
Cranberry varieties have differing needs for N – larger fruit, larger plants (leaves) and bigger crops mean more N is needed
Most growers developfertilizer programs basedon N.
5UMass Cranberry Station
How cranberries get nitrogen
From soil• Cranberry soil very sandy - holds little• Organic matter - 1-2% only
From recycling in the plant• Some stored in stems and roots
From fertilizer
6UMass Cranberry Station
Compare cranberry to other crops
Plant leaf tissue Avg. applied
Crop Nitrogen (%) Nitrogen (lb)
Cranberry 0.9-1.1 20-60
Blueberry 1.0-1.5 45-65
Apple 2.0-2.5 50-60
Peach 2.5-3.0 80
Corn 2.9-3.5 160-200
Wheat 2.6-4.0 75-110
7UMass Cranberry Station
Nitrogen use in cranberry
If growers get N wrong – they pay a price in plant growth and crop
There is a body of research on N needs and rates
8UMass Cranberry Station
Disadvantage to too much N
Davenport, Stevens in BC
9UMass Cranberry Station
N rate decision tree – from the BMPs
Use less N if:• No or low crop• Native varieties• Deep peat• >3% organic• You sanded• You pruned• Tissue N >1.1%• Uprights long/runners• Frost damage• Insect/disease damage
Use more N if:• Bog renovated or new• Ben Lear or Stevens• Mineral soil• <1% organic• You mowed• Crop was heavy• Tissue N <0.75%• Uprights stunted/thin• Heavy bloom• General yellowing
10UMass Cranberry Station
Nitrogen Form - Ammonium
Several studies show best growth and N uptake with ammonium (compared to nitrate)
Ammonium taken up 10x faster than nitrate
Little conversion of ammonium to nitrate at low pH; ammonium leaches less
Nitrogen – Nitrogen Cycle
Ammonium Soil T Low pH Removal in
crop (~23 lb in 150 bbl)
Fertilizer
12UMass Cranberry Station
When do cranberries need nutritional support? Applications
coincide with growth and fruiting demands of the plants
Late May through early August
13UMass Cranberry Station
Environmental considerations
Biggest concern is movement of N in surface water
Leaching limited • layered soil and barrier layers (why the
bog can hold a flood) • ammonium N forms
Groundwaterpathway – totalextent unknown
14UMass Cranberry Station
Flooding practices
CES/SMAST Field Study Cranberry Bog NET Nitrogen Loss
Bog ID --> EH PV BEN WS M-K ASH
Irrigation 0.4 1.5 0.6 0.2 1.7 2.4Groundwater 0.0 0.0 1.0 0.3 0.0 0.0
Frost Protection 0.8 1.8 1.4 0.5 1.6 2.0Pest Management 0.0 0.2 0.1 0.1 0.1 0.1
Harvest 1.3 3.4 4.5 1.2 4.2 2.9Winter Protection 3.0 3.7 5.2 1.4 4.8 4.0
Total IN 5.5 10.5 12.8 3.6 12.4 11.3
Drainage/Infiltration 5.7 6.7 10.5 4.6 7.7 7.2Harvest 2.1 5.3 9.4 4.3 4.5 2.8Winter 4.0 4.6 6.4 1.7 4.0 5.2
Total OUT 11.9 16.5 26.3 10.5 16.2 15.2
Net Nitrogen Loss (lb/a/yr)= 6.4 6.0 13.5 7.0 3.7 3.8
Pine-Oak Forest 0.4Cranberry Bog Nitrogen Output 6.4 (Flow Through Bog = 8.6) Residential (density 1 per 2.5 acres) 5.7Direct Precipitation on Bay 9.8
Nitrogen Outflow from Bog
Nitrogen Output to Downgradient Systems (lb N/acre/yr)
Nitrogen Inflow to Bog
16UMass Cranberry Station
How can we reduce N output?
Practice BMPs regarding rate, timing, split applications
Look at it more as a water problem• Amount of flow• Direction of flow• Pathway of flow
17UMass Cranberry Station
Amount of flow
Follow recommendations on flooding, drainage, and irrigation
Research on looking at how to limit groundwater upwelling • Compare 2 upwelling sites (10 lb/a/yr) vs.• 4 not upwelling sites (5 lb/a/yr)
18UMass Cranberry Station
Direction of flow
Diversion• Tail water recovery
Can also relate to attenuation
Research on how to limit flow-through situations – by-pass canals?• Compare flow-through (8.6 lb/a/yr)• To all other types (6.4 lb/a/yr)
19UMass Cranberry Station
Pathway of flow
Attenuation function of ponds, steams, and wetlands
Mill Brook watershed (Howes and Millham, 1991)• TDN leaving the bog was 0.99 ppm• Downstream the load had decreased to 0.71 ppm
Vegetative channels or retention ponds between the bog and the final discharge point – how to best accomplish this?
20UMass Cranberry Station
Literature review - attenuation
Denitrification in wetlands is effective at attenuating N• NO3 to N2
Denitrification in ponds and streams • Ponds – 50% attenuation
• 2 studies: 39-95% and 84-96%• Streams – 30% attenuation
• 30-40% observed in riverine systems
Uptake by vegetation less effective
21UMass Cranberry Station