I 12 
Journal of Agricultural Research 
Vol. II, No. 2 
Table V .—Effect of straw and nitrate on sweet-orange, sour-orange, and grapefruit 
seedlings growing in California soil at Washington , D. C. a 
SOUR ORANGE (Citrus aurantium L.). 
Lab¬ 
oratory 
No. 
Soil treatment. 
Condition of seedlings 
after 7,3 days. 
964 
Check. 
Normal; growing. 
965 
.do. 
Do. 
966 
Finely ground straw (i per cent).. 
Yellowish. 
967 
.do. 
Do. 
968 
Finely ground straw (2 per cent). 
Do. 
969 
.do. 
Do. 
970 
Finely ground straw (1 per cent) 4 - N as KNOs (0.02 per cent). 
Normal; growing. 
971 
.do. 
Do. 
972 
Finely ground straw (2 per cent) + N as KNOs (0.02 per cent). 
Do. 
973 
.do. 
Do. 
SWEET ORANGE (Citrus sinensis Osb.). 
988 
989 
Check. 
Normal; growing. 
Do. 
.do...!. 
974 
Finely ground straw (1 per cent). 
Yellow. 
975 
.do. 
Do. 
976 
Finely ground straw (1 per cent) +Nas KNOs (0.02 per cent). 
Normal; growing. 
977 
.do. 
Do. 
GRAPEFRUIT (Citrus grandis Osb.). 
986 
Check. 
Normal. 
987 
do. 
Do. 
978 
Finely ground straw (1 per cent). 
Yellow. 
979 
.do. 
Do. 
980 
Finely ground straw (1 per cent) + N as KNOs (0.02 per cent). 
Normal. 
981 
.do. 
Do. 
a Orange and grapefruit seedlings about 2 months old were transplanted into paraffined pots containing 
virgin soil from near Riverside, Cal.; plants were watered with distilled water; all drainage was caught 
and returned to each pot, thus preventing any change in salt content. 
The destruction of cellulose by molds and bacteria is extremely rapid 
in both good and poor areas, but no correlation of laboratory results 
and field conditions has as yet been possible. The total number of bac¬ 
teria in good and poor areas is erratic and seems without significance. 
The total nitrogen content and also the nitrogen-fixing power of the 
poor soils is slightly above that of the good soils, as shown in figures 1,2, 
3, and 4. Similar data have been reported by Headden (1910) for soils 
of the irrigated orchard regions of Colorado. Contrary to Headden’s 
