what fertilizer should i use? bob stevens extension soil scientist wsu- prosser stevensr@wsu.edu

What Fertilizer Should I Use?

Bob Stevens

Extension Soil Scientist

WSU- Prosser

stevensr@wsu.edu

What Fertilizer Should I Use?

Well that depends!!!!!!!!!!

Starting Points

• You have determined what plant nutrient your vines need.

Starting Points

• You have determined what plant nutrient your vines need.

• Once in the plant where it is needed ions from all sources are “equal”.

Starting Points

• You have determined what plant nutrient your vines need.

• Once in the plant part where needed ions from all sources are “equal”.

• Goal in selection of WHAT is to have nutrients in adequate “concentration” at the “plant part” at the “right” time.

The How & the When Affects the What

The How & the When Affects the What

• How Soil application Water application – drip Foliar spray

The How & the When Affects the What

• When Planning for future crop needs

• Soil test & plant analysis• Crop & management history

Responding to “real & perceived” needs• Growth patterns• Visual symptoms• In-season plant analysis

The How and the When Affects the What

• The bottom line is “time from application to plant availability”.

Organic

Vineyard

Conventional Other

Organic

Vineyard

Conventional Other

Soil Maintenance

PlantResponse

Conventional Vineyards

• Drip Irrigation Product solubility Product compatibility with irrigation water

• pH• Salts• Specific ion concentration (Ca++, HCO3

- )

Conventional Vineyard

• Soil applied inorganic sources Product reaction with soil chemistry Application method

• Broadcast Area covered Incorporation

• Band

Organic Vineyards

“Must meet organic certification criteria”

Organic Sources

• Crop residues (cover crops)

• Manures

• Compost

• Other sources

Organic Sources What’s Available

• Quality Nutrient value C:N ratio Maturity of compost Type of manure

• Transportation costs

5/13/03

5/13/03

52 lbs N/Ac incorporated with clover tops

C:N Ratio of Cover Crops

Cover Crop

Small grain

Vetch

Clover

C:N Ratio

Research Commercial

32 29

13 16

17 20

K Bair

Organic Sources Nutrient Availability

• Distribution

• Soil contact

• Soil Microbial activity Warm soil Moist soil

2005 Soil Test NO3-N Research Vineyard (0-6")

Date

May Jun Jul Aug Sep Oct Nov

mg

kg-1

NO

3-N

0

10

20

30

40 FertilizerControlFall VetchFall CloverF

ull

Blo

om

Ve

rais

on

2005 Soil Test NO3-N Commercial Vineyard (0-6")

Date

Jun Jul Aug Sep Oct Nov

mg

kg-1

NO

3-N

0

10

20

30

40 Spring VetchFall VetchVetch Half/HalfSpring CloverFall CloverBloodmeal

Full

Blo

om

Vera

ison

R2 = 0.9134

0

1

2

3

4

5

6

7

8

9

10

19 20 21 22 23 24

Temperature (oC)

pp

m N

O3-

N

Soil NO3-N vs. Temperature

All Compost is not created

“equal”

Compost Considerations

• Changes in composted material will impact final compost quality

• Compost analysis may change over time

• More mature compost slower N release

Vineyard Nutrient Management Challenges

• Deficit Irrigation Where is the nutrient? Where is the water?

• Dry Spring soil moisture

Nutrient Source Management

• Have a PLAN

• Monitor the results Site specific

• Make adjustments gradually over time

Nutrient Source Management

• Have a PLAN

• Monitor the results Site specific

• Make adjustments gradually over time

• Sustainable practices maintain soil quality and optimize vineyard management goals.

N

P

KCa

B

Mg

S

Cu

Mo

Mn

Zn

Fe

Cl