152 



CALIFORNIA FRUITS: HOW TO GROW THEM 



and unfertilized plots, respectively, should be carefully measured 

 and the results calculated from the point of view of the cost of the 

 fertilizer and its application, and the profit accruing from its use. 



Fertilizers may be broadcasted or drilled in. In any case, an 

 attempt should be made to incorporate them with the soil thoroughly 

 and preferably five or more inches beneath the surface. If this is not 

 done, there is danger, especially where deep and constant summer 

 cultivation is practised, that the fertilizer will remain in the dry 

 surface soil mulch, which is not accessible to the feeding roots. If 

 the fertilizer is broadcasted, it may be cultivated, plowed or disked 

 in. The above precaution relative to thorough and deep incorpora- 

 tion of fertilizers is particularly pertinent and important in the case 

 of the insoluble fertilizers like dried blood, high-grade tankage, rock 

 phosphate and similar materials. 



Choosing the Fertilizer for the Test. Based on practical ex- 

 perience and observation in the field, the writer believes that under 

 most orchard and vineyard conditions in California and especially in 

 the Great Valley and under the more arid conditions, nitrogenous 

 fertilizers are the most likely, of all the commercial brands, to yield 

 profitable responses. Among these, sulphate of ammonia is, in gen- 

 eral, to be preferred to nitrate of soda, but the latter may be used 

 where heavy rainfall and a tendency to soil acidity is the rule. The 

 organic nitrogenous fertilizers are all suitable, and when nitrogen 

 in that form can be purchased more cheaply than in either of the 

 forms just mentioned, it should be so employed. 



If it is desired to test other fertilizers, then phosphatic fertilizers 

 should receive second consideration, and then it is well to treat a 

 plot of five acres with nitrogen alone, one of the same size with 

 superphosphate alone, and one with a combination of the two, 

 always having a control plot in addition, as above explained. Sim- 

 ilarly, if it is desired to test potash or sulphur, these fertilizer 

 materials may be used alone or together with the others in much 

 the same manner as described for nitrogen and phosphorous 

 fertilizers. 



The mixed commercial fertilizers are strongly advised against, 

 because much more is paid for every unit of the necessary elements 

 in that form than in the form of the so-called simples like those 

 listed above. Besides, it will be found rare under California orchard 

 and vineyard conditions that potash fertilization, in addition to 

 nitrogen and phosphorus, can be made to pay, and yet the price of 

 potash is very high. 



How Much Commercial Fertilizer to Apply. In using nitro- 

 genous fertilizers, a fairly safe standard for amounts, in the absence 

 of more definite information than we have now, is the following, 

 which is merely furnished as an example : 



Citrate of soda ISO Ibs. per acre 



bulphate of ammonia 100 



Dried blood or high grade tankage. ...... 300 



Superphosphate 300 



Sulphate or chloride of potash 200 



Sulphur 100 



