ii6 THE CONNECTICUT POMOLOGICAL SOCIETY 



FERTILIZERS IN FRUIT GROWING 



By DR. E. H. JENKINS, Director of Connecticut Agricultural Experiment Station 



WE FIND in the substance of fruit trees, as in that of 

 all crops, considerable quantities of potash, lime, 

 magnesia, sulphuric and phosphoric acids, and 

 relatively small amounts of soda, iron and chlorine. We 

 have no data as to the total quantities by weight of these 

 things in the whole tree, and we know that the different 

 parts of the tree contain very different amounts. Thus the 

 young wood contains a larger per cent of potash and phos- 

 phoric acid in the dry substance than the old wood. Two 

 years ago I saved all the trimmings from sixteen yearling 

 peach trees, and determined several fertilizer ingredients in 

 them. I found in the dry twigs: 



Pounds per acre 

 {150 tree^) 



Nitrogea, i.oi per cent 0.70 



Phosphoric acid, .21 percent 0.14 



Potash, .47 per cent 0.33 



Lime, .97 per cent 0.68 



This, of course, represents only the growth which is cut off. 

 We know that these things, although forming but a ver)' 

 small part of the whole tree, less than -^ of the twigs, 

 less than -joT o^ the inner wood of the tree, are absoluteh* 

 essential to the plant's life. However small the total quan- 

 tity, a certain amount is indispensable. 



There are four things — not three — which, generally speak- 

 ing, the fruit grower has specially to look out for in his 

 fertilizers : nitrogen, phosphoric acid, potash and lime. 

 The first three we need not saj' another word about, but 

 why name lime with them? Because, for one thing, our 

 Connecticut soils, excepting in the western part, are not 

 limestone soils, and are not rich in lime ; although they may 

 contain naturally more available lime than potash or phos- 

 phoric acid, yet it is quite likely that, unless care is taken, 

 lime may become relatively deficient in fruit orchards. 



Then, again, the growth of Avood and of leaves of fruit 

 trees makes much larger demands on the lime of the soil than 



