5^ 



per acre. In many cases, the smaller amounts of K2O will doubt- 

 less give better net returns than the larger, though there are some 

 soils where this is apparently not the case. In certain of our cul- 

 tural methods experiments, a fertilizer similar to this has very 

 good results, especially in connection with tillage. In some cases 

 in connection with sod or mulch treatments, however, it has seemed 

 probable that the nitrogen was hardly sufficient in the above form- 

 ula, though this is a point that will have to be determined more or 

 less by local trial. The nitrogen can, of course, be furnished by 

 manure or leguminous plants to a greater or less extent, if this is 

 found desirable. 



In a few of our orchards, moreover, no form of fertilization 

 has as yet produced a material response. This we consider due to 

 the presence of other limiters, of which iuiproper moisture supply is 

 frequently important: though there are many other possible limiters. 



The existence of such orchards emphasizes the need of local 

 tests before making large and regular expenditures for fertilizers. 

 These tests can be readily made by treating one part of the orchard 

 and leaving the remainder unfertilized. In the case of most young 

 orchards, or in any orchard that is doing well in growth and fruiting 

 and retains a thrifty foilage well through late August and Septem- 

 ber, it is doubtless safest to fertilize only a small portion of the or- 

 chard for two or three years and leave the larger part unfertilized. 

 The fact that the trees are well loaded in a given year, however, is 

 no sufficient reason for omitting the fertilizer that year. In fact, 

 that is one of the best reasons and times for applying a proper fer- 

 tilizer rather liberally, in order to prevent the total absence of a 

 crop the following year, and in the long run to tend to steady the 

 annual production. 



In case of the reverse conditions, — old orchards or those not 

 retaining a thrifty look throughout the season or not growing and 

 bearing satisfactorily, — it is best to reverse the procedure, and fer- 

 tilize the larger portion, leaving only a small block to test the value 

 of the treatment. In all cases, however, we strongly advise the use 

 of a check until the real value of the treatment is well established. 

 It is neither desirable to throw away money by too much liberality 

 in the treatment of a crop, nor to fail to realize its possibilities by 

 too niggardly a treatment. Either course is an economic blunder, 

 and the latter is especially deplorable because its effects is to de- 

 crease the productivity of the whole nation. 



The time of application also we consider important, especially 

 in the case of the nitrates. hile our evidence is by no means com- 

 plete on this point, yet we believe that it is quite posible to make the 

 applications either too early or too late for satisfactory results. In 

 fact, we have some evidence, from the work of certain orchardists, 

 that leads us to believe that very distinct harm may be done by ap- 

 phdng nitrogen too near to the fruit-setting time, especially in the 

 case of peaches. Other evidence indicates that nitrates applied too 

 early in the season may be wholly lost to the trees. 



So that all things considered, we feel that nitrates should be 

 applied not earlier than petal-fall in apples and probably not later 

 than the ist of July, though some of our best results have come 



