608 
Philippine Jourml of Science 
1920 
The culture numbers and sets of salt proportions in each of 
the cultures actually used in this work are shown in Table 3. 
The culture numbers are shown in the first column, and the 
numbers of gram molecules of each of the three salts are shown 
in the three following columns. Besides the cultures supplied 
with fertilizers, three control cultures, which had no addition of 
salts, were included in the series. 
The soil used in these tests was a clay loam collected from 
the college mulberry plantation, near the seed laboratory. Into 
each culture vessel (an ordinary 5-gallon, tin petroleum can) 
were placed approximately 20 kilograms of thoroughly mixed 
soil. The fertilizer salts were added to the cultures on July 4, 
1918. This was done by first preparing stock solutions of each 
of the salts with rain water. The necessary amount of each 
stock solution was then added to three liters of water, and the 
solution thus obtained was thoroughly mixed with the soil of 
the culture. 
The rice employed in the present study was of the variety 
known as sanglay puti, a variety sometimes grown as a lowland 
rice with continuous irrigation, but more frequently grown as an 
upland rice, without irrigation and depending on the precipita- 
tion of the rainy season. The seeds used had been harvested on 
October 13, 1917, from a crop grown on the college farm. They 
were soaked in water for twenty-four hours and were planted 
on June 8, 1918, in shallow seed boxes. The seeds germinated 
on June 10, and made uniform and healthy growth. On July 6, 
when three leaves had developed, eight apparently similar seed- 
lings were transplanted to each of the culture vessels, the soil 
having been previously prepared and the salts added as above 
described. After transplanting the seedlings the soil in each 
culture was saturated with water. The cultures were allowed 
to remain in the shade until July 16, when they were transferred 
to full sunlight in a location where they were all exposed to 
nearly uniform conditions of light and wind. They were wa- 
tered every day in order to maintain an approximately constant 
water level — about 3 centimeters above the soil surface — in all 
of the cans. On July 26, four plants were removed from each 
culture, leaving the four largest plants. On July 31, two more 
plants were removed, leaving the two largest plants in each 
culture. Harvest occurred on October 16, 1918, the grain and 
tops being collected separately, and the number of fruiting pani- 
cles in each culture being recorded. The grain and tops were 
