What Fertilizer Should I Use? Bob Stevens Extension Soil Scientist WSU- Prosser

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

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 Plant Response

Conventional Vineyards Drip Irrigation  Product solubility  Product compatibility with irrigation water pH Salts Specific ion concentration (Ca ++, HCO 3 - )

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

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 K Bair

Organic Sources Nutrient Availability Distribution Soil contact Soil Microbial activity  Warm soil  Moist soil

Soil NO 3 -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 K Ca B Mg S Cu Mo Mn Zn Fe Cl