﻿EFFECT OF BORAX ON GROWTH AND YIELD OF CROPS. 17 



whether they were planted after the intervening of a light rain. 

 The use of 10 pounds per acre decidedly checked growth when applied 

 in the drill, but was only slightly harmful when sown broadcast. 



FIELD EXPERIMENTS USING FERTILIZERS WITH AND WITHOUT BORAX. 



A COMPARISON OF TWO GRADES OF SEARLES LAKE POTASH IN THE FIELD. 



In connection with certain studies in commercial fields to deter- 

 mine the comparative effectiveness of different potash carriers on 

 the potato, a test of two grades of muriate of potash from Searles 

 Lake was included. The two grades differed in that one, the so-called 

 1919 grade, contained 6.25 per cent of borax, while the other grade, 

 designated 1920, contained practically none. 



The tests were conducted cooperatively in Virginia, New Jersey, 

 and Maine, as follows: 



At Cape Charles, Va., in cooperation with the Virginia Track Experiment Station; 

 on Sassafras sandy loam; fertilizer application, 1,800 pounds per acre; average con- 

 trol, 7-8-0; variety grown, Irish Cobbler; yield, 161.7 bushels per acre. 



At Norfolk, Va., in cooperation with the Virginia Truck Experiment Station; on 

 Norfolk sandy loam; fertilizer application, 1,800 pounds per acre; average control, 

 7-7-0; variety grown, Irish Cobbler; yield, 221.3 bushels per acre. 



At Holmdel, N. J., in cooperation with the New Jersey Agricultural Experiment 

 Station; on Sassafras loam; fertilizer application, 1,500 pounds per acre; average 

 control, 4-10-0; A r ariety grown, American Giant; yield, 246 bushels per acre. 



At Presque Isle, Me., in cooperation with the Maine Agricultural Experiment Sta- 

 tion; on Caribou loam; fertilizer application, 1,800 pounds per acre; average control, 

 5-10-0; variety grown, Irish Cobbler; yield, 243.7 bushels per acre. 



The detailed results are shown in Table 8. 



The data in Table 8 disclose the fact that in most of the tests, 

 especially as the quantity of borax was increased, the yields were 

 reduced. At two of the stations the fertilizer mixtures containing 

 the 1919 potash salt (6.25 per cent borax) were applied in two ways: (1) 

 by means of the planter which applies the fertilizer in a furrow 

 made by the planter plow and (2) by means of a fertilizer distributer 

 which gives a somewhat greater spread to the application. It will 

 be noted that the former method, which presumably afforded a 

 greater concentration of the fertilizer-borax mixtures near the potato 

 seed pieces, gave the poorer results. The fertilizer mixtures con- 

 taining the so-called 1920 grade of potash salt (practically free from 

 borax) gave excellent returns, comparing very favorably with other 

 potash carriers. 4 In the experiment at Holmdel, N. J., it will be 

 observed that the fertilizer-borax mixtures gave better results than 

 the no-borax mixtures when applied with the distributer. The chief 

 explanation for this lies perhaps in the heavy rainfall following plant- 

 ing which undoubtedly was sufficient to reduce the concentration of 

 the borax to a point whereby stimulation, rather than injury, may 

 have resulted to the extent of increasing the yields. When applied 

 with the planter in the drill row, as is ordinarily done by the potato 

 grower, the degree of injury was considerable, as is shown in the first 

 figure column of Table 8. It is well to state in this connection that 

 the results obtained during the same season at New Brunswick, 

 N. J. (2), tend to support the foregoing explanation. At New Bruns- 



* A report on the effect of various potash salts upon crop yields on prominent soil types is in course of 

 preparation. 



