Evaluation of Composted Poultry Manure & Potassium as Plant Nutrient Supplements

in Tomatoes

BEN LEACOX, AGRICULTURAL TECHNICIAN, UC, WOODLAND MIKE DAVIS, PLANT PATHOLOGIST, UC DAVIS GENE MIYAO, FARM ADVISOR, UCCE, YOLO, SOLANO & SACRAMENTO COUNTIES

66 days before harvest

Premature vine senescence 18 days before harvest 8 days before harvest

Composted poultry manure, K applications, & chemigations Yolo-Zamora area, 2014 (as supplements)

K = 157 ppm @ 2.5% K on CEC

Composted manure, NPK and K applications, Muller Ranch, Yolo-Zamora area, 2014

composted manure 10 T/A

composted manure

5 T/A Sidedressed

K (as KCl)

manufacturer NPK to mimic compost rates

lbs/ton (%) availability 76 lbs N (3.8%) 20% 48 lbs P205 (2.4%) 80% 58 lbs K2O (2.9%) 80% 7:1 C:N

Potassium Sidedressed KCl

Composted Manure Poultry

J.H. Meek and Sons, Woodland, 2014

Composted poultry manure applications (supplemental)

Yield response expected < 180 ppm soil K

Yield response expected < 2.0% K of the CEC

@ full bloom

2.56 LSD @0.05

From small-scale, test plot results ...

... to grower experimental adaptive use

LIMITED INTEREST: High Cost$ (w/ short supply) Slow operation (high volume) Specialized equipment

KCl fertilizer donated by Agriform & Tremont Group

I. Placement (of compost) II. Materials (compost vs. conventional fertilizer) III. Rates: potassium @ 50 100 200 400 lbs/acre

Research plans for 2015

Cooperators: Steve & Sam Meek & John Pon Colin, Frank & Louie Muller Bob & Bill Payne Dustin & Ron Timothy & Dave Viguie

Compost: UCD Russell Ranch

Research collaborators: Johan Leveau Nilesh Maharaj Karina Perez Hung Doan & many others