III. Fertilizers: Utilization and Types

Introduction  World demand for increased food, feed, and fiber production necessitates us of fertilizers.

Fertilizers  Fertilizers are materials occurring naturally or commercially produced for application to soil for the purpose of adding one or more deficient nutrients

Fertilizers  Research says that optimum ferts use increase yields world wide by 50%

Fertilizer History  Farmers used ferts lavishly before  After 74, fuel and energy cost skyrocketed!  Farmers needed more money, so they selected soil and crops that used ferts the best.  But bottom line, fert does not cost, it pay!

Fertilizer Trends and Economics  Dry bagged fert use decreased with the increase use of dry-mix and liquid fert.

Fertilizer Trends and Economics  Ferts cost represent about 20% of all crop productions  Producers expect a corresponding increase in yield of 50%  This is a return of two to three dollars for every dollar spent

Fert is Profitable When:  1. Based on a soil test  2. Added in an efficient manner  3. Soil is managed

Fert is Unprofitable When:  1. Soil moisture is limited  2. Pest and adverse temps are a problem  3. Increased yield has less market value than cost of ferts.

Fertilizer Efficiency Point of Diminishing Return Point at which cost of applying additional fert is unprofitable in terms of increased production

Determining Fertilizer Needs  Amount and Type depends on: –1. Amount removed by previous crop –2. Amount lost by leaching and other processes –3. Amount and type of nutrients available in soil –4. Climatic conditons –5. Requirements of present crop –6. Crop quality desired

Determining Fertilizer Needs  Just do a soil test analysis! Idiot!

Types of Ferts.  1. Organic  Derived from plant and animal material  2. Inorganic  Contains no C, H, and O’s

Forms of Fertilizer Materials 1. Dry-Mix Made by combining selected elements into a bulk blend comes in a granular form 2. Liquid Material completely dissolved in solution May contain a single nutrient or mixture 3. Gaseous Anhydrous ammonia

Numbers on the Bag

Types of Fertilizers  Nitrogen –N–N  Phosphorus –P–P  Potassium –K–K

Fert Grade and Quality Control  Label must contain: –Weight of material –Manufacturer’s name –Manufacturer’s address

Fert Grade and Quality Control  Example:  Contains 10% Nitrogen, 20% P 2 O 5, and 10% K 2 0  60% of the product is conditioners (to reduce caking), acidity neutralizers (Lime), fillers (extender added to improve uniform distribution of nutrients

Nitrogen Ferts  Material 1. Ammonium nitrate 2. Ammonium sulfate 3. Anhydrous ammonia 4. Aqua ammonia 5. Organic products 6. Urea  Nitrogen Content (N%) 33.5% 20 – 21 % 82% 20-24% 1-12% 45-46%

1. Ammonium Nitrate  NH 4 NO 3  50% is ammonium form and the remainder is in nitrate form.  The two allow nitrogen to be used immediately

2. Ammonium sulfate  (NH 4 ) 2 SO 4  High in cost  Best forms of N for rice crops

3. Anhydrous ammonia  NH3, is the principle nitrogen fert.  Applied by injection into moist soil behind tractor at about 6 inches deep.  Made from atmospheric nitrogen and natural gas in Texas plants.

4. Aqua ammonia  NH 3 + H 2 0  A low pressure nitrogen fert, applied three inches below soil surface.

5. Organic products  Sludge, Manure, Meat Meal, Cottonseed Meal, and fish meal.

6. Urea  A controlled release fert.  Formed by coating granular urea with sulfur, then wax, then clay.

Phosphorus Ferts.  Material 1. Basic Slag 2. Bone Phosphate 3. Rock Phosphate 4. Superphosphate, ordinary 5. Superphosphate, triple Multiple P% by to obtain P 2 O 5 % equivalent.  Phosphorus Content (P%) 3.5 –

1. Basic Slag  Low-phosphorous by-product of iron and steel mills  Used mainly in areas where produced

2. Bone phosphate  Steamed bone meal  Oldest known phosphate fertilizer

3. Rock phosphate  Mainly from Florida

4&5. Superphosphate  Rock phosphate mixed with sulfuric acid = superphosphate  Rock phosphate mixed with phosphoric acid = triple superphosphate

Potassium Ferts  Material 1. Muriate of potash 2. Sulfate of potash 3. Sulfate of potash magnesia 4. Potassium nitrate 5. Potassium polyphosphate Multiply K% by to obtain K 2 O% equivalent  Potassium Content (K%)

Ferts supplying other nutrients Lime Sulfur Boron Molybdenum Iron Zinc Magnesium

The End