TABLE 2.-ANNUAL AND TOTAL AMOUNT OF ORGANIC MATERIAL PRODUCED BY THE COVER CROPS AND THE NITROGEN RE-
 TURNED TO THE SOIL BY THE LEGUMES (TOPS ONLY) IN THE PECAN EXPERIMENT.


 Cover Crop



Austrian peas .................
C. spectabilis .................

Hairy vetch .......................
C. spectabilis ................

Check--Unplanted,
 light growth of
 native vegetation.

Oatst ....... ........
C. spectabilis ............ ....
Hairy vetcht .................


When
Grown


Winter
Summer

Winter
Summer




Winter
Summer
Winter


 Dry
Matter
Avg. *
Percent

 18.8
 28.6

 18.2
 28.6




 26.0
 28.6
 18.2


Nitro-
 gen -
 Avg.*
Percent

 2.15
 1.45

 3.10
 1.45




 1.05
 1.45
 3.10


Pounds per Acre of Organic Material Grown and Returned
 to the Soil


 1928
Green Dry**


16,532
6,316

13,503
6,534





6,534
13,400


3,108
1,806

2,457
1,869


Green

15,681
***

7,840
***


Dry**

2,948

1,427


Plot



1

2


3


4


 1930
Green I Dry**

4,791 901
7,100 2,031

1,000 182
13,500 3,861


 500
14,100


130
4,033


 1931
Green Dry**

20,000 3,760
2,500 715

32,000 5,824
3,000 858


1,000
3,000


260
858


 Averages of numerous analyses of materials (oven dry) grown at Gainesville, made by the Department of Chemistry
 and Soils over a period of years, and not of samples taken from the pecan experiment.
 ** Calculated from the oven dry percentages.
*** Crotalaria was not weighed in 1929.
 t Rye was grown in 1928-29 and 1929-30.
 : Hairy vetch was grown for general comparison in Plot 4 the first winter of the experiment, 1927-28.


 775 202
1,869 *** .....
2,439 ............