l8o JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
Table IV. 
Spring Section. 
Yields of Green Crops at Time of Digging in. 
Sown August 20-21, 1919. Dug in April 8-10, 1920. 
Crop. 
r^lOi. 
Fresh Tops. 
Ash-free organic matter 
(roots included). 
Tons per acre. 
Mean. 
Cwt. per acre. Mean. 
Crimson Clover 
( 
"t 
30 
43 
17 
16 
3 
7 
f 
17-0 
43 
-J 
Rye 
J 
t 
20 
45 
7 
9 
0 
7 
} 
8- 4 
38 
- 2 
Rape 
{ 
29 
40 
11 
9 
2 
5 
) 
1 
io*4 
35 
' I 
Turnip . 
J 
1 
32 
4i 
7 
8 
0 
6 
l 
f 
7-8 
25 
O 
Vetches 
1 
1 
39 
9 
8 
2 
1 
I 
r 
8-6 
23 
'3 
Red Clover 
5 
I 
27 
46 
2 
5 
7 
0 
1 
j 
3'9 
14 
2 
Mustard 
{ 
36 
37 
2 
8 
i 
2-8 
13 
7 
Oats 
I 
I 
33 
44 
1 
3 
8 
5 
; 
2-7 
13 
O 
Black Medick 
\ 
34 
47 
1 
4 
} 
1*4 
8 
4 
Lupine . 
J 
t 
3i 
42 
} 
( 
2 J 
2 2 
) 
Control (Weeds) 
.25 
2 
(incl. ) 
8 
■ 1 
roots) 
I 
These figures clearly show the superior yield of the non-legumes 
in the autumn. The five non-leguminous crops produced an average 
of i6*6 cwt. per acre of ash-free organic matter against only 6*5 for 
the four legumes (neglecting lupines), of which only vetches made a 
growth comparable with the non-legumes. In the spring, of course, 
the growth was much greater, and although as a whole the non- 
legumes still led, the margin was small, the average yields of ash-free 
organic matter in cwt. per acre being respectively 25*0 and 22*4. 
Moreover, crimson clover is head of the list by a big margin. It will be 
noticed that in two cases the spring figures are less than the autumn 
ones. In the case of mustard this is due to the fact that the cr6p 
was in full flower in the late autumn, and when turned under in the 
spring was dying down. In the case of oats the wet weather in the 
winter caused the green tops to rot away, so that the spring figure 
represents almost solely new growth made in the late winter and 
early spring, and does not include the decayed remains of the first 
growth ; in a more fortunate season no doubt the figure for oats in 
spring would more nearly approach that for rye. 
The yields of turnips obtained on the plots green manured with 
the above green crops are shown in Tables V. and VI. 
