Get Ready for RAPs:Nutrient Management Planning for Vegetable Farms

Becky Maden, UVM Extension

VVGBA Annual Meeting

January 25, 2016

UVM Extension

2015-16 Soil Fertility Project

• Proactive approach to RAPs• VVGBA listserv survey in spring of 2015

– Based on results, began to develop tools for outreach

• Working with 11 commercial vegetable farms– Soil tested nearly 1000 acres– Making recommendations and tracking inputs for

2016

• Goal is to understand—– Are soil test recommendations followed?– How to improve fertility management?– Practical approaches for RAPs compliance

Why Soil Fertility Matters

•Improved crop quality•Increased yields•Save money on unnecessary fertilizer•Accurate year to year record keeping•Better environmental stewardship•Comply with water quality regulations (RAPs)

Why Manage Soil Fertility?

Another Regulation??• Vermont Water

Quality Bill passed in June 2015 by the VT legislature

• Draft RAPs released October 2015

• Next draft of RAPs to be released soon

• Second comment period to follow

Be sure to comment!

Draft RAPs:Key Points for Veg Farms

• Must soil sample every 3 years

– Fertilization must be according to soil test recommendations

• Must keep records of all inputs

• No manure or compost on any fields >20 ppm soil P

• Cover crop seeding dates on flood plains

• Compost/ manure storage requirements

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<2 2-5 5-10 10-15 15-20 20-25 25-30 30-35 35-40 40-50 50-100 100-200 200+

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UVM soil test ppm

"commercial vegetable" soil tests 10/14-11/15Soil Test Phosphorus Levels

Commercial Vegetable Soil Tests 10/14-11/15

UVM Soil Test ppm

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26% of Samples Are Above 20 ppm

Preparing for RAPs

• Test your soil.

• Plan your amendments for next season based on soil tests.– Reduce or eliminate P applications where

necessary.

• Create a simple record keeping system for soil fertility if you don’t already have one (or ask us for a template).

• Continue good soil health practices.– Cover cropping, reduced tillage, etc.

• RAPs will require soils to be tested with Modified Morgan Extract– UVM, UMAINE, UMASS labs

– UVM standard soil test is $14

• Logan and Waypoint (A&L) use Melich III– Different extraction method

produces different results

– Difficult for UVM Ext to interpret and offer recommendations.

Which Soil Lab to Use?

Soils Lab Comparison

Lab-----> Waypoint Logan UVM

pH 7.3 7.4 7.8

OM% 7.1 8.78 8.2

Sulfur 19 ppm 19 ppm 10 ppm

Phosphorous 220 ppm 398 ppm 65.7 ppm

Calcium 4859 ppm 2675 ppm 13795 ppm

Magnesium 158 ppm 153 ppm 224 ppm

Potassium 196 ppm 302 ppm 202 ppm

Sodium 20 ppm 64 ppm 16 ppm

– Standard Fertility Test--pH, organic matter, macro and micro nutrients, % Base Saturation, CEC. Best for overall crop planning and first year high tunnels. UVM, UMAINE, UMASS.

– PSNT (Pre Sidedress Nitrogen Test). Use during season to determine how much N to sidedress. Best for N intensive crops like potatoes or corn. UVM, UMAINE, UMASS.

– Tissue Sampling. Use to determine deficiencies on longer season crops. UMAINE, UMASS.

– SME (Saturated Media Extract). Tests for levels of available nutrients. Best for potting media or high tunnel soils. UMAINE, UMASS.

Which soil test to take?

If Your Soil is High in P…

Under Draft RAPs:

• Limits management tools for organic growers

– No compost or manure additions

– No use of fertilizers with animal based manures

• No more Giroux or Kreher’s or other poultry fertilizer

• Especially challenging on sandy soils—how to build up organic matter without compost?

• Curbs ability of diversified farms to produce on-farm fertility with compost/ manure.

• Reduces use of local resources for soil amendments.

If Your Soil is High in P…

• Cover crop!– Legumes for on farm N

– High biomass cover crops for organic matter

• Reduce erosion potential by planting or maintaining buffers.

• Create a soil fertility plan with no P additions– Select N fertilizers that are not

manure based.• Seed meals, feather meal.

If Your Soil is High in P…

Cover Crops

Cover Crops

• Best source of organic matter and nitrogen without adding any phosphorus

• Gain between 50-130 lbs N/ acre from legume cover crop

– Depends on crop, density, and timing

• Very affordable source of N

• Difficult if land base is tight

Questions?