Fertilizing and Watering

Agenda● Watering

● How much water● Techniques

● Fertilization● Fertilizer Components● Types of Nitrogen● Calculating Organic Mixtures● Applying Fertilizer● Fertilizer Problems

●

How Much Water is Needed

● 1 to 1.5 inches per week● Soil appears dark leaves wet outline on

hand.● Between 40 and 70% of soil capacity.● Over watering is as bad as not enough

– The biggest reason non commercial plants die in GA is over watering

● Allow for rain

How Much to Water

●On a DCGO plot one inch of water is about 20 gallons

A cubic ft =7.48 gallons1 inch on a 4x8 ft plot is 2.67 cubic ft or

19.95 gal●Needed between 20 to 30 gallons total per week

●Water flow is 12 gallons per minute maximum●Only 2 minutes at full pressure

How To Water● Possible Methods

– Hose and nozzle aim stream at the ground around the roots

● use appropriate pressure– Sprinkler can water the roots– Soaker hose place under the mulch

● Flow meters and timers are available● If using a timer make sure all connections are

tight and don't drip.● Avoid leaves as much as possible

When to Water

● Best time is morning shortly after due evaporates

● Late afternoon is also good● Try to avoid mid day when water

evaporates quickly● Avoid late in the day when water will

remain on the leaves and encourage fungus growth

Fertilizer Components● Nitrogen

– Urea– Ammonia Nitrate– Nitrate

● Phosphate P2O2● Potassium● Trace Element● Inert Ingredients

Trace Minerals

● Not present in all fertilizers● Include: sulfur, iron, magnesium, copper and

zinc● May need to add separately

Some Organic Fertilizers

Row 1 Row 2 Row 3 Row 40

2

4

6

8

10

12

Column 1

Column 2

Column 3

Ammonium Nitrate

● NH4● Most commonly in the form (NH4)2SO4● Absorbed by soil● Converted by soil bacteria to NO3,Nitrate● In the form NH4NO3 is explosive

Urea

● NH2-CO-NH2● Form of nitrogen in some organic fertilizers● Can be lost to volatilization● Water soluble

Nitrate

NO3

Not absorbed into the soil

Product of microbial action on ammonium fertilizers NH4

Can be lost to leeching

Test Report

Organic Fertilizers to Use

Calculating Fertilizer

● Take fertilizer recommendation and calculate pounds needed of N, P and K

● Example recommendation:● UGA recommends 30lbs 10-10-10 per 1000

sq ft approximately 1 lb 10-10-10 for a 4x8 bed

● 1.6 oz each of N, P and K(32/1000)*48● Use 4-3-4 organic fertilizer from big box

store and bat guano

Calculation Continued

● Need N and K 40 oz (1.6 / .04)● P .03 * 40 = 1.2 oz still need .4 oz of P● Bat Guano 0-7-0 5.7 oz (.4/.07)● Mix 2.5 lbs Holly Tone (40oz) with 5 ¾ oz

bat guano

Dawgs to the Rescue

● http://aesl.ces.uga.edu/soil/fertcalc

When to Fertilize● Sweet Corn

– 12” tall, one month later● Leafy green vegetables

– 3-4 weeks after emergence● Onions

– 3-4 weeks after emergence● Tomatoes, peppers, and eggplants

– First fruits 1” diameter● Cole crops (broccoli, cabbage, cauliflower)

– 2-3 weeks after transplanting then 2 wks later

Nitrogen Deficiency

Yellowing of the leaves,showing first in older leaves and lack of growth

Potassium Deficiency

Older leaves and/or leaf edges are yellow or brown; leaves may be chlorotic (yellow) and curl, and may have necrotic (burned/brown) spots, limited to older leaves.

●Phosphorous Deficiency

older leaves to become dark green and have red or purple patches in them. Growth can be stunted and/or the plant can have late flowering/maturing fruits

Calcium Deficiency

● Stunted● Distorted cupped

shaped leaves● Interveinal chlorosis● Symptoms appear

first on new growth● Blossom end rot on

tomatoes

Magnesium Deficiency● Yellow or white areas

between the veins of older leaves at first

● Yellowed areas may turn into dead spots

● Older leaves in plants may be purple or bronze

● Plants may be stunted and have a yellow appearance

Zinc Deficiency

● First become light green.

● Leaves are deformed, dwarfed and crumpled

● Terminal blossoms set pods that drop off, delaying maturity

Excess Nitrogen● May run off into the

environment● “Leggy” stems● Delayed Maturity● Reduced yields● Reduced quality

– Softer– lower nutritional

content– less sugar

Questions

Thank you