191S] AGRICULTUEAL BOTANY. 221 



solubility in water, its value in correcting acidity, its value in the fai-mation 

 of nitrates, its influence upon the growth of plants, and the rate of loss from 

 the soil. 



"On the basis of the results obtained it was concluded, (1) that an applica- 

 tion of limestone in which the entire product consists of very fine material is 

 less desirable from the standpoint of permanent agriculture than one consisting 

 of varied degrees of fineness; (2) that an ideal application of limestone is 

 one in which there is sufficient fine material (60-mesh) to meet the immediate 

 needs of the soil and thus allow time for the coarser particles to disintegrate; 

 [and] (3) that if the entire product will pass a 10-mesh screen and include 

 all of the fine material, it is sufficiently fine for soil improvement if applied 

 somewhat in excess of the immediate needs of the soil. Such a product should 

 contain at least 50 per cent of material that will pass a 60-mesh screen." 



Eflfect of sulphur on different crops and soils, O. M. Siiedd (f7. S. Dept. 

 Agr., Jour. Agr. Research, 11 (1911), No. 4, pp. 91-103). — Investigations are 

 reported from the Kentucky Experiment Station on the effect of applications of 

 100 and 200 lbs. of flowers of sulphur on soy beans, clover, oats, alfalfa, and 

 wheat, grown on eight rather depleted surface soils, each representative of a 

 distinct soil type in Kentucky. The experiments were conducted in triplicate 

 in the greenhouse. Tabulated data show the weight of the total air-dried 

 materials for each crop on each soil type ; the total and sulphate sulphur in 

 air-dried soy beans, clover, and alfalfa ; the percentage of sulphur as sulphate 

 in 16 varieties of garden and field seeds before and after germination ; and the 

 protein content of air-dried soy beans, tops and seed. 



In summarizing the author states that " the results show that the sulphur 

 increased the production of some crops, had no effect on others, and on some 

 was injurious, depending on the crop and the soil on which it was grown. 

 There was a preponderance of gains, however, from the sulphur application, 

 but these were generally small. 



"Analyses of some of the crops show that the sulphur increased the total 

 and sulphate-sulphur content of the plant, and the greater the application the 

 greater the increase. Where sulphur was applied to clover and alfalfa the 

 excess sulphur in those plants was in the form of sulphate, while in soy beans 

 part of the excess was in another form. 



" In soy beans which showed an increased sulphur content, no corre- 

 sponding increased protein content was always found. In five instances out 

 of eight, however, soy beans grown in soil where sulphur was added show an 

 increase in the total weight of protein. 



" It was found that of the 16 varieties of field and garden seeds examined 

 some contain sulphates, white others do not, but that on germinating all except 

 2 form a greater or less amount of sulphate. The highest sulphate content 

 obtained in the ungerminated seed was 0.048 per cent in clover, and the increase 

 due to germination varied from none in corn to 0.035 per cent in the onion. 

 There was a slight loss in only one sample — clover." 



AGRICULTURAL BOTANY. 



The effect of one plant on another, S. Pickebing {Ann. Bot. [London], SI 

 (1917), No. 122, pp. 181-181, figs. S). — Washings from growing plants have been 

 shown to be deleterious to other plants reached by such washings. Susceptible 

 plants thus far found include apple, pear, plum, cherry, forest trees (six kinds), 

 mustard, tobacco, tomato, barley, clover, and two varieties of grasses. Plants 

 exerting this injurious influence include apple (seedlings), mustard, tobacco, 

 44073°— 18 -3 



