Plant Nutrition Mrs. Gill

Pee-Cycling http://www.npr.org/blogs/thesalt/2014/0 7/31/336564120/should-we-return-the- nutrients-in-our-pee-back-to-the-farm

Major Nutrition 3 Major Elements oxygen (O) hydrogen (H) carbon (C) Considered to be non-fertilizer nutrients and make up 96% of plant’s tissue Acquired through natural processes from air and water

Macro Elements Divided into two groups, macro and micro Macro Nitrogen – N Phosphorus – P Potassium – K Calcium - Ca Magnesium - Mg Sulfur - S

Micro Elements Chlorine – Cl Iron - FE Manganese – Mn Boron – B

Micro Elements Cont.. Zinc – Zn Copper – Cu Nickel – Ni Molybdenum - Mo

Soil tests Determines which nutrients are present and which are deficient for growing a variety of crops

Soil Sampling (Simplified) Take random samples from the area to represent the area you want to test Mix all of the samples together Complete the soil test info sheet Mail the sample and info sheet to a reputable lab Usually a University Extension Program Analyze results and make production decisions

Plant Requirements large amounts of major elements relatively small amounts of minor elements

Fertilizer Any material added to a growing medium that provides nutrients for plants Vary in what they contain, how they are applied, and the function they serve

Commercial fertilizers The fertilizer analysis shows % or pounds per cwt. (100#) of the three major elements in large numbers on the container or bag Nitrogen (N), phosphate (P), and potassium (K) or Potash

Commercial fertilizers 5-10-5 5% N, 10% P, 5% K remaining 80% is filler NP&K are always listed in that order.

Fertilizer Forms Liquids Granules Salty so they dissolve in water Sprayed on root zone or as a foliar application Have high tendency to ‘burn’ plants Are usually short-lived Granules Most common form Heavy pellets don’t drift too far Can be slow-release

Fertilizer Forms Tablets and Spikes Large compressed items that are pushed into the soil or placed in a hole Expensive for the amount of nutrient they contain Release nutrients very slowly over time Several months to more than a year

Nutrient Solutions Nutrients in solution are measured in parts per million or PPM. Fertilizer rates can be taken from tables in reference books or to instructions with their injector system, or growers can calculate the amount of fertilizer needed to reach a desired PPM.

The chosen fertilizer is calcium nitrate with an analysis of 15-0-0. An example problem might call for 200 PPM nitrogen. The chosen fertilizer is calcium nitrate with an analysis of 15-0-0. A rule of thumb in calculating PPM is that 1 ounce of anything in 100 gallons H2O equals 75 PPM.

Problem: Wanted, 200 PPM N 15-0-0 Calcium Nitrate Multiply the percent of the nutrient in the given fertilizer by 75. .15 N × 75 = 11.63 PPM N (if 1 oz added to 100 gallons) 200 divided by 11.63 = 17.2 oz of fertilizer needed in 100 gallons to get 200 PPM.

If the injector system delivers 1:100 (one gallon concentrate mixed with 99 gallons water for a total of 100 gallons), 17.2 ounces of fertilizer is needed for each gallon of concentrate. If the tank holds 30 gallons of concentrate, 516 ounces (32.25 pounds) of fertilizer is needed to deliver 200 PPM

Choosing a Fertilizer Things to consider Nutritional need Application method Price Availability Personal Preference Safety/Environmental Concerns Placement is critical—GPS systems

Nitrogen has most noticeable effect on plants encourages above ground vegetative growth regulates use of other elements Leaches easily

Too much Nitrogen lowers disease resistance weakens stem because it promotes long, soft growth lowers fruit quality delays maturity increased susceptibility to cold

Symptoms of Nitrogen Deficiency yellow or light green color stunted root and top growth

Nitrogen Deficiency in Corn

Phosphorous held tightly by soil particles not easily leached

Phosphorous encourages cell division flowers and seeds don’t form without it hastens maturity, offsetting quick growth caused by nitrogen

Phosphorous encourages root growth makes K more available increases disease resistance improves quality of grain, root and fruit crops

Insufficient Phosphorus susceptibility to cold susceptibility to plant diseases poor quality fruit and seeds

Symptoms of Phosphorus Deficiency purple color on underside of leaves reduced flower fruit and seed production

Potassium Works with Nitrogen and Phosphorus to improve plant growth development of chlorophyll efficient use of CO2

Potassium increases disease resistance encourages healthy root systems essential for starch formation

Insufficient Potassium leaves appear dry and scorched with irregular yellow areas on the surface

Lime CaCO3- Calcium Carbonate acts as a plant food affects soil acidity soil acidity affects availability of plant food elements

Is Soil Alive? ¼ teaspoon of fertile soil contains approximately: - 1 Earthworm - 50 Nematodes - 52,000 Algae - 111,000 Fungi - 2,920,000 Actinomycetes - 25,280,000 Bacteria

Earthworms Decompose organic matter Mix plant litter with soil Tunneling helps with aeration of the soil

Nematodes Examples are: Roundworms, threadworms, hair worms Consume other microbial organisms which help regulate the microbial population Also found in the roots of the plants

Algae Contain chlorophyll (photosynthetic) Soil algae are too small to be seen with the naked eye, but in large numbers can give the surface a green color They favor damp soil that is exposed to the sun Help with the formation of soil structure

Fungi Examples: Grow on dead and decaying tissue Mushrooms, mold, mildew, rusts, yeasts Grow on dead and decaying tissue Primary agent of organic matter decay Make nutrients available by decomposing organic matter.

Actinomycetes Rod-shaped form of bacteria Can live under drier conditions than bacteria, very abundant in sod One of the most important agents in the soil for decomposing and breaking down cellulose Its what gives freshly tilled soil its smell

Bacteria Most numerous and MOST IMPORTANT! Diverse metabolism aides in breaking down organic chemicals like pesticides Can also degrade inorganic materials Fix Nitrogen so it can be used by plants

Why do we need microorganisms in Agriculture? Decay plant residue Fix nitrogen Break down nutrients needed by plants Break down cellulose Finally, much of the soil is not available to the plants until the microbes break it down