768 



HORTi culture: 



June 6, 1908 



A Chemical Study of Some Greenhouse Soils 



During the .spring of 1907 the 

 writer's attention was called to a 

 sample of cucumber soil that was sent 

 to Dr. George E. Stone, of the Depart- 

 ment of Vegetable Pathology of the 

 Massachusetts Experiment Station. 

 An examination made of the plants 

 grown on this soil revealed the fact 

 that no fungus disease was present* 

 — the plants were very vigorous, but 

 turned yellow prematurely and failed 

 to devtiop a crop of fruit. Some of 

 the leaves were spotted and resem- 

 bled the Mosaic troubles sometimes 

 seen on other plants. As nearly as 

 we could find out the treatment of 

 the soil had been about as follows: 



Two years previous to the trouble 

 the soil had been prepared by adding 

 an equal amount of horse manure to 

 pasture sod; more manure was added 

 when the soil was transferred to the 

 house and when the crop was put in, 

 for undersround heat, a trench of 

 manure and chopped straw was used. 

 An application of lime was made to 

 the surface of the soil before putting 

 out the crop and during the growing 

 season considerable nitrate of soda 

 was used. We were not able to as- 

 certain the treatment of the soil dur- 

 ing the two succeeding years, but it 

 is quite probable that it was similar 

 to that already described. 



It was the belief of the pathologist. 

 Dr. Stone, that the soil was over-fer- 

 tilized and. in order to throw some 

 light on the subject, the writer under- 

 took the chemical analysis of the 

 soil. 



In order that the results may be 

 more intelligently interpreted by the 

 average reader, I have reported them 

 in comparison with the average chem- 

 ical analysis of thirty-eight samples 

 of barn yard manure. 



I Average an- 

 j alysis of 

 I Cuoumber barn-yard 

 I soil. I mannre. 



The above results show the cucum- 

 ber soil to be considerably richer in 

 nitrogen and phosphoric acid than are 

 the better gardes of farm yard ma- 

 nure. 



A further study of the soil was 

 made in order to ascertain how much 

 of the plant food was soluble in 

 water, as no doubt it is the soluble or 

 available portion of the saline constit- 

 uents that is responsible for the in- 

 jurious effect upon the growing crop. 

 The results of this study will be found 

 reported in comparison with other 

 analyses in the subsequent tables. 



During the spring of 1908 a sample 

 of cucumber soil was received by Dr. 

 Stone from Orange. Mass., and an- 

 other from Baldwinsville. Mass. A 

 description of the behavior of the 

 plants indicated that the difficulty 

 might be due to an accumulation of 

 soluble saline constituents; in other 

 words, an excess of plant food. In 



•For a more extended pathological de- 

 scription of the trouble see article by Dr. 

 G. E. Stone, in this Issue. 



order to malie a systematic study ot 

 the whole problem it became neces- 

 sary to obtain data as to the average 

 composition of a normal cucumber 

 soil giving excellent results. The 

 writer, therefore, obtained three such 

 soils from well-known growers in the 

 state and subjected them to the same 

 treatment as was given the abnormal 

 soils. 



A given weight of the samples was 

 leached out with a definite volume of 

 hot water, the resulting solution was 

 evaporated to dryness on a water 

 bath and a chemical analysis was 

 made of the saline residue. 



In the table Sample No. 1 repre- 

 sents the Baldwinsville soil. No. 2 

 represents the Orange soil and No. 3 

 represents the soil analyzed in 1907. 

 Nos. 4. 5 and 6 represent normal cu- 

 cumber soils procured from well- 

 known growers from various localities 

 in Massachusetts. The results in the 

 first table have been calculated to 

 100 parts of dry soil for the sake of 

 comparison. 



To bring this matter out more 

 strikingly, I have prepared a table 

 showing the average composition of 

 the three abnormal as compared with 

 the three normal soils. 



TABLE NO. 3. 

 Showing an average ot the composition 

 of the soluble constituents in the three 

 abnormal soils as compared with the 

 three normal soils. Results expressed In 

 pouuds per acre. 



To express in a more intelligent 

 manner to the average reader the 

 serious excess of water soluble plant 

 food as shown in the abnormal col- 

 umn of table No. 3. a calculation has 



TABLE NO. 1. 



Showing the per cent, of wate r soluble constituents in 100 parts of diT so il, 

 i Abnormal Soils. | Normal Soils. 



Total solids... 



Soluble nitrogen 



.Soluble potash 



Soluble phosphoric acid. . . 

 Solul'ie cilcium oxide.... 



Soluble sodium oxide 



Soluble magnesium oxide. 

 Soluble Sulphates (So3)... 



No. 6 

 .19 

 .025 

 .026 

 .002 

 .03 

 .075 

 .009 

 .008 



In this table note the large amount 

 of total solids representing saline con- 

 stituents and humus matter, also the 

 high potash phosphoric acid, sodium 

 oxide, magnesium oxide, and sul- 

 phates in the first three samples as 

 compared with the normal soils Nos. 

 4. 5 and 6. 



In table No. 2 the results have been 

 expressed in pounds of the various 

 constituents per acre and are based 

 on the usual estimate that an acre 

 of soil 1 ft. deep weighs 3.000.000 

 pounds. The results in this table 

 were all calculated to normal soil 

 moisture which averages about 20 per 

 cent. 



been made which shows that it would 

 take 4 1-4 tons of nitrate of soda to 

 furnish the nitrogen; 9 1-4 tons ot 

 high-grade sulphate of potash analyz- 

 ing 50 per cent. K20 to furnish the 

 potash ; 2 3-4 tons of acid phosphate 

 to furnish the phosphoric acid and 

 3-4 tons of burned lime to furnish 

 the calcium oxide. Or, to express 

 the results in terms of a mixed fer- 

 tilizer it would require an application 

 of 17 tons of mixed fertilizer made 

 up of the highest grade of material 

 and analyzing about 4 per cent nitro- 

 gen, 27 per cent, actual potash and 

 2 1-2 per cent, phosphoric acid. 

 When we consider that the above 



TABLE NO. 2. 

 Showing the amount of water soluble constituents in an acre of the several 

 soils with average moisture conditions (20 per cent). 



Pounds per Acre. 



Abnormal Soils. 



Normal Soils. 



Total solids 



Soluble nitrogen 



.'Soluble potash 



Soluble phosphoric acid. . . 

 Soluble calcium oxide.... 



Soluble sodium oxide 



Soluble magnesium oxide. 

 Soluble sulphates (So3)... 



No. 1 



44,160 



1.200 



12,000 



960 



1.536 



5,280 



1.296 



1,656 



No. 2 



40,329 



288 



9,810 



1,080 



1,U80 



5,040 



S(V4 



864 



No. 3 



27,300 



2,457 



5.733 



491 



1,365 



4,641 



737 



1,201 



No. 4 

 10,944 



600 

 2,040 



408 

 1,128 

 1.632 



528 

 1,296 



No. 5 

 7,056 



132 

 1,320 



168 



744 

 1,440 



216 



No. 6 

 4,560 



eno 



624 

 48 

 720 

 1,800 

 216 

 192 



In the above table observe the ex- 

 cessive amount of total solids, and 

 the various constituents in the first 

 three soils as compared with the last 

 three soils. I would also call special 

 attention to the composition of soil 

 No. 6 which is a comparatively new 

 soil, it having been used for growing 

 cucumbers only two or three seasons, 

 but with very flattering results. Note 

 the comparatively small amount of 

 total solids and soluble saline con- 

 stituents. 



figures only represent that portion ot 

 plant food present in the soil wliich 

 is soluble in wnler and that the total 

 amount of plant food in the several 

 abnormal soils runs from 8 to J/U per 

 cent, higlier in many cases, we begin 

 to realize what an enormous accumu- 

 lation of plant food has taken place and 

 we only wonder that the plant can 

 male a start in growth. It may be 

 interesting in this connection to know 

 that the results of some investigations 

 on tobacco soils that the writer has 



