discovered at Rothamsted that turnips without manure fail to 

 develop, the roots becoming no larger than radishes. The cause of 

 this remarkable collapse is not clear. This same plot that fails 

 altogether to produce turnips gave us last year a fair crop of wheat, 

 23*9 bushels of grain and 20*4 cwt. of straw per acre; and two years 

 earlier it had given 11*4 bushels of barley and 10*1 cwt. of straw. 

 The phosphoric acid in the soil is now reduced very considerably and 

 this is no doubt an important factor in depressing the yield. Man- 

 golds on continuously unmanured land do not fail in this complete 

 manner, indeed the only other crop on our farm that behaves like 

 swedes is clover. The phenomenon is not connected with the fact 

 that crops of turnips have previously been growing on the same land, 

 because in 1908 a crop of turnips was taken in Barnfield on the man- 

 gold plots (mangolds having failed) where no turnips had been grown 

 since 1870, and the unmanured plot gave identical results with the 

 unmanured plot on Agdell. Equally remarkable is the curious effect 

 of clover taken two years previously in depressing the yield on the 

 unmanured and on the completely manured plots, the drop being from 

 8 cwt. to 2*3 in the former case and from 587 to 463 cwt. in the latter. 



There is evidence that the exhaustion of lime from the com- 

 pletely manured plot, which is accelerated by the use of ammoniaca) 

 manures, is beginning to affect the plant, and this year we noted a 

 considerable amount of finger and toe. 



The yield of grass was poor. The dry weather in April kept 

 the plant back and no satisfactory growth began till too late. Cutting 

 took place on June 19th and 20th, and the hay was harvested in 

 good condition. A heavy second cut was obtained on September 

 10th and 11th. There were more weeds than usual, especially on 

 Plot 8 which receives phosphates, sodium and magnesium salts, 

 but no potassium salts or nitrogenous manures : here the weeds 

 formed two thirds of the herbage while the leguminosa^ formed only 

 5 per cent. Addition of potassium salts to the manure (Plot 7) 

 doubled the crop but halved the proportion of weeds so that the 

 gain was almost wholly in the clovers and grasses. Addition of nearly 

 2| cwt. (275 lb.) nitrate of soda to this complete manure did not 

 increase the crop ; the explanation is to be found in the fact that the 

 clovers are adversely affected so that the natural nitrogen-gathering 

 power of the herbage is diminished, while weeds come in and take 

 their place. Thus the quality of the herbage actually suffers. One of 

 the most important practical lessons brought out by the Rothamsted 

 Grass Experiments is that the manuring of grass land is a matter 

 that requires very intelligent and careful consideration. The added 

 manure favours some of the species at the expense of the rest. A 

 new type of herbage may even set up, which may be very different 

 from the old. Of course, on temporary grass land and leys of short 

 duration the case is different ; here nitrogenous and other artificial 

 manures exert their full effect and no complication arises through 

 change of flora or suppression of the clovers. 



The trials with the new nitrogenous fertilisers were continued 

 and are giving a steady accumulation of valuable information with 

 regard to their effects on the different crops. This year nitrate of 

 lime, nitrite of soda, and nitrate of ammonia were used on mangolds 

 in Little Knotwood Field, and all gave crops equal to that obtained 

 from nitrate of soda. But this result does not necessarily prove that 



