USE OF COMMERCIAL FERTILIZERS 



It is not within the scope of this department to make recommendations regarding the use 

 of commercial fertilizers. The Department of Agronomy and the Department of Biochemistry 

 of the University of New Hampshire Agricultural Experiment Station test soils an'^, conduct 

 experimental work with various fertilizer materials on hay and crop land. The Department 

 of Horticulture investigates fertilizer treatments for fruits and vegetables. Much of this 

 work has "been published, and is available for free distribution to residents of New Hamp- 

 sliire . Address your request to Mail Service, University of New Hampshire, Durham, New Hamp- 

 shire. A list of currently available publications on fertilization follows: 



Growing Apples in New Hampshire. 

 Growing Vegetables at Home. 

 Asparagus in New Hampshire . 

 Growing Potatoes in New Hampshire . 

 Growing Strawberries in New Hampshire . 

 Forage Crop Production in New Hampshire. 

 Growing Peaches in New Hampshire . 

 Culture of Low-B\iSh Blueberries . 

 Growing Grapes in New Hampshire. 

 Cane Fruit Culture. 

 Tomatoes for New Hampshire. 



Soils and Their Crop Adaptation in New Hampshire . 

 Forage Variety Trials in New Hampshire 1951-1956. 

 Folder New Hampshire Recommendations for Seed, Fertilizer and Lime. 



While the word "fertilizer" does not appear in all of the above titles, none is in- 

 cluded which does not discuss the use of fertilizer. 



CONFORMITY TO GUARANTEE 



The chemical analyses reported in this bulletin were made by the methods adopted by 

 the Association of Official Agricultural Chemists. The following list indicates the number 

 of samples equaling or failing to meet guarantee : 



Number of samples analyzed I69 



Equaling or exceeding all guarantees 96 



Deficient in nitrogen only 4l 



(11 subject to penalty) 



Deficient in phosphoric acid only 8 



(3 subject to penalty) 



Deficient in potash only 13 



(8 subject to penalty) 



Deficient in nitrogen and phosphoric acid 1 



(1 subject to penalty in nitrogen) 



Deficient in nitrogen and potash 3 



(1 subject to penalty in potash) 



Deficient in phosphoric acid and potash 3 



(1 subject to penalty in both) 

 (1 subject to penalty in potash) 



Deficient in magnesium oxide 1 



Deficient in magnesium oxide and nitrogen 2 



(1 subject to penalty in MgO) 

 (1 subject to penalty in both) 



Deficient in magnesium oxide and phosphoric acid 1 



(subject to i>enalty in MgO) 



Fifty samples were guaranteed to contain magnesium oxide . Of these eighteen guaranteed 

 in terms of water soluble magnesium oxide. All magnesium oxide guarantees were met with 

 five exceptions. Eight samples were analyzed for boron and all met the guarantee. 



Penalties were assessed on 29 different lots of fertilizers representing 12 grades. 

 Four grades, 0-15-30, 8-I6-I6, I5-IO-IO- and 10-10-10 were involved in 19 of the lots penal- 

 ized. The others were scattering, one or two only in a particular grade. The penalty clause 

 was invoked in twelve cases for nitrogen, four cases for phosphoric acid, eleven cases for 

 potash and in four cases for magnesium oxide. These cases are indicated in the table of 

 analyses by underline of the result found. The manufacturers are listed alphabetically and 

 the brand names by formula and alphabetically under the name of the manufacturer. 



There are far too many small deficiencies as shown by the fact that only 96 out of 169 

 samples met all guarantees . This problem is of serious concern and considerable coopera- 

 tive work is underway to solve the problem. Fertilizers are largely mixtures of chemicals. 

 Segregation of these materials in the bag is difficult to prevent. Modern methods of 

 fertilizer manufacture are doing much to process the fertilizer in such a way that segrega- 

 tion will be avoided. The solution of this problem is difficult. To obtain a truly repre- 

 sentative sample of a fertilizer mixture requires careful work. The chemist can accurately 



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