- -  AGRICULTURE CORE CURRICULUM - -


(CLF6000) Advanced Core Cluster: ORNAMENTAL HORTICULTURE

 (CLF6350)  Unit Title: ELEMENTS NECESSARY FOR PLANT GROWTH

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 (CLF6359)  Topic: METHODS OF            Time     Taught in Year(s) 
                     APPLICATION           1 hour         3 and 4   
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        Topic Objectives: Upon completion of this lesson the student will 
        be able to:

        Learning Outcome #:

          (H-14) - Demonstrate at least three common methods of fertilizer 
                    application.

        Special Materials and Equipment: Small test plots to experiment
                    with various fertilizer application methods

        References: Interstate Printers and Publishers, Inc.
                    Western Fertilizer Handbook.
                    Pages 169-183.

        Evaluation: Quiz by instructor

TOPIC PRESENTATION: METHODS OF APPLICATION

A. Fertilizers are used to supply nutrients that are not present in the 
   soil in amounts needed by the crop.

   1. Many crops require multiple applications of fertilizer materials.

   2. Several methods of application may be used.

B. The broadcast method of applying fertilizer involves the uniform 
   distribution of dry or liquid materials over the entire soil surface. 

   1. Many different applicators have been perfected to do this job. 

   2. The fertilizer is spread in a swath ranging from 30 to 60 feet wide. 

   3. Speed of travel and various metering devices determine the amount 
       applied. 

   4. Care needs to be taken to avoid overlaps or gaps of the swaths.

   5. This is an economical and rapid method of spreading most 
       fertilizers.

   6. This method is preferred and much safer. In some situations bonding
       can easily create a toxicity (i.e., boron and molybdenum).

C. Injection (deep application) refers to a method of placing fertilizers 
   below the soil surface.

   1. Mounted knives or shanks are placed on a tool bar. 

   2. Fertilizers that can be broadcast can also be injected. 

   3. This is an excellent method of placing immobile nutrients into the 
       root zoneof the crop.

   4. This method also helps prevent fertilizer losses due to 
       volatilization into the atmosphere, wind blowing it away, or water
       moving the material from where it has been placed. 

   5. For trees, fertilizers can be trenched-in, holed-in, or injected 
       under pressure into the root zone. 

D. Banding is a method of placing fertilizers to the side of and/or below 
   the seed. 

   1. Applicators for banding are usually mounted on the same tool bar as 
       the seeder. 

   2. A tube connects the tank or hopper to a furrow opened by a disc or 
       shoe. 

   3. Depending on soil type and crop, the fertilizer can be placed to the 
       side and below the seed or directly below the seed. 

   4. Bonding is preferred when applying the immobile nutrients, such as
       phosphorus, to a crop having a small root system, such as very young
       seedlings.

E. Fertilizers applied in the irrigation water are often called water-run 
   applications. 

   1. Savings of labor, equipment, time, and fuel costs are advantages of 
       this method. 

   2. Applications may be preplant or postemergence. 

   3. There are some faults to this system. 

       a. When water distribution is not even, the fertilizer districbution 
           is not even.

       b. This type of application is limited to the time when irrigations 
           go on (sometimes late fall and winter applications are 
           preferred). 

F. Some of a crop's nutritional needs can be met by applying nutrients of a 
   compatible fertilizer to the foliage (foliar application).

   1. Foliar application is usually used in situations where a quick
       response is required. 

   2. Micronutrient deficiencies can often be corrected in this manner. 

   3. The applications can be made through over-crop sprinklers, aerial 
       application, or ground rig. 

   4. Experiments show that most crops respond better to foliar feeding 
       when applications are made during the morning hours. 

   5. Some materials will work with one species of crop (or tree) and not 
       for another. 

G. Trunk injection of nutrients is a method that has found some success for 
   deficient fruit trees. 

   1. Elements that are needed in very small amounts have been most 
       successful (i.e., zinc, copper, iron).

   2. Dry powders can be placed in holes bored in the tree trunks. 

   3. Some work is being done experimentally by using high pressure 
       injection into trunks. 

   4. Drawbacks are 

       1. that wounds made using this technique allow entry of heart rots
           and other diseases, 

       2. and it is limited to the use of the minor elements.

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         ACTIVITY: 
                     
         1. Have students use the above mentioned methods on test
             plots of crop plants. Compare results. 

         2. Have students use foliar applications on canned 
             nursery specimens and observe and record their 
             findings.

             a. Use different combinations, both in amounts 
                 of nutrients and types of elements. 

             b. Vary the time of applications, for example, 
                 time of day when applied and stage of growth 
                 of the plants.
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12/14/90 PJK/sg


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