10 On the Rain and Drainage - Waters at Rothamsted. 
in lbs. per acre. The estimated composition of the farmyard- 
manure applied on Plot 2 must be taken as approximate only. 
The small quantities of magnesia and soda credited to Plots 
11-13 are contained in the bone-ash used. 
All the manures, except the dung, are sown broad-cast ; 
during sowing two screens are carried along the boundaries of 
the plots to prevent the manure being carried beyond its proper 
limits. The autumn manures are ploughed or harrowed in as 
soon as possible after sowing, the wheat being drilled afterwards. 
The spring manures are top-dressed. 
The farmyard-manure, the superphosphate, and the sulphates 
of potassium, sodium, and magnesium, have always been 
applied in the autumn. During the first six seasons in 
which the drainage-waters were collected the ammonium-salts 
were applied on all the plots in the autumn, and had been 
uniformly so applied for many years previously. Since 1872-3 
the ammonium-salts have been applied on Plot 15 at a different 
time from the other plots. In the five seasons, 1872-3 to 
1876-7, Plot 15 received its ammonia in the spring, the other 
plots in the autumn. Since this time the order has been 
reversed. Plot 15 receiving ammonium-salts in the autumn, and 
all the remaining plots in the spring. The nitrate of sodium 
has always been applied in the spring. 
As the dates of sowing manure and of harvest are points 
which must be borne in mind in discussing the composition 
of the drainage-waters, a summary of these particulars is given 
in Table XXXIX. 
Table XXXIX. — Dates of Sowrao Mantiees and of Harvest in 
Beoadbalk Field, 1866-7 to 1880-1. 
Manubks Applikd. 
Season. 
Ammonium-salts. 
Wheat Cut. 
Mineral Manures. 
Nitrate of 
Plot 15. 
Other Plots. 
Sodium. 
1866-7 
Nov. .5-6. 
Nov 
. 5-6. 
Mar. 25. 
Aug. 23-24. 
July 22-28. 
1867-8 
Oct. 30-Nov. 1. 
Oct. 30 
-Nov. 1. 
„ 18. 
1868-9 
„ 28-31. 
Oct. 28-31. 
Apr. 1. 
Aug. 16-18. 
1869-70 
„ 30-Nov. 2. 
Oct. 30 
-Nov. 2. 
Mar. 25. 
„ 5-12. 
1870-1 
„ 18-22. 
Oct. 18-22. 
„ 23. 
21-23. 
1871-2 
„ 16-17. 
Oct. 16-17. 
„ 7. 
„ 16-17. 
1872-3 
„ 17-18. 
Mar. 25. 
Oct. 17-18. 
,. 25. 
„ 15-19. 
1873-4 
„ 27-28. 
M 19- 
„ 27-28. 
„ 19. 
„ 3-11. 
1874-5 
„ 20-23. 
„ 23. 
„ 20-23. 
„ 23. 
,. 16-21. 
1875-6 
„ 29-30. 
„ 24. 
„ 29-30. 
„ 24. 
„ 8-19. 
1876-7 
„ 16-17. 
Apr. 11. 
„ 16-17. 
Apr. 11. 
„ 18-24. 
1877-8 
Nov. 2-3. 
Nov. 2-3. 
Mar. 14. 
Mar. 14. 
„ 1-10. 
1878-9 
Oct. 14-15. 
Oct. 14-15. 
„ 10-13. 
„ 10. 
Sept. 4-17. 
1879-80 
„ 22. 
„ 22. 
„ 9. 
9. 
Aug. 14-20. 
1880-81 
„ 15-16. 
„ 25. 
„ 12. 
„ 12. 
„ 8-11. 
1881-2 
„ 27-28. 
,. 27-28. 
Feb. 23. 
Feb. 23. 
