GRASS FOR HAY 



21 



Table XI. — Produce of J/aj/ per aor. Average over the period of 57 years (1856- 

 1912), the 10 years (1903-1912), and. the individual year 1912. Rothamsted. 

 Total of Jirst and second crops (if any). 



Plot. 



3 



12 

 2 



5-1 



5 

 17 



4-1 



8 



7 

 5-2 



6 



15 



4-2 

 10 



9 



11-1 



11-2 



16 



14 



Abbreviated Description 

 of Manures. 



lUnraatuired every year 



I 

 Unmanured ; following Farmyard Dung for first 



8 years 



(N. half) Unmanured ; following Ammonium-salts 



alone for 42 years ...... 



Ammonium-salts alone ( = 43 lb. N.); with Farm- 

 yard Dung for first 8 years .... 

 Ammonium-salts alone = 86 lb. Nitrogen (to 1897) 

 Nitrate of Soda alone = 43 lb. Nitrogen 



Superphosphate of Lime ..... 

 Mineral Manure without Potash .... 

 Complete Mineral Manure ..... 

 (S. half) Complete Mineral Manure; following 



Ammonium-salts alone for 42 years . 

 Complete Mineral Manure as Plot 7; followiug 



Ammonium-salts alone first 13 years . 

 Complete Mineral Manure as Plot 7 ; following 



Nitrate of Soda alone first 18 years . 



Superphosphate and Atnmonium-salts = 86 lb. N. . 



Mineral Manure (without Potash^), and Ammo- 

 nium-salts =86 lb. N 



Complete Mineral Manure and Ammonium-salts 

 -:86 lb. N 



Complete Mineral Manure and Ammonium-salts 

 = 129 lb. N 



As Plot 11-1, and Silicate of Soda. 



Complete Mineral Manure and Nitrate Soda 

 = 43 lb. N 



Complete Mineral Manure and Nitrate Soda 

 = 86lb. N 



* After the change. 



t 



t 



' Including Potash first 6 years. 



Before the change, 42-9 cwt. || 54 years only (1859-1912). 



,, 495 cwt. i 56 years only (1858-1912). 



„ S0-6cwt. *♦ 42 years (1856-1897). 



,, 35-4 cwt. ft 15 years (1898-1912). 



The Unmanured Plots. 

 Two of the plots have remained without manure during the whole of 

 the experiment. They are situated near the extremities of the field, and 

 show a slight but constant difference in crop. Taking the average of the 

 whole period, these unmanured plots have produced rather more than a 

 ton of hay per acre per annum. If we compare the successive ten-year 

 returns, there is no sign of approaching exhaustion or great falling-off' in 

 crop from year to year. The impoverishment of these unmanured plots is 

 more to be seen in the character of the herbage than in the gross weio-ht 

 of produce. Weeds of all descriptions occupy the land, and the relative 

 proportion they bear to the grasses and clovers has increased from year to 



B 2 



