July 5, 1893.] 



Garden and Forest. 



281 



GARDEN AND FOREST. 



PUBLISHED WEEKLY BY 



THE GARDEN AND FOREST PUBLISHING CO. 



Office : Tk;bune Building, New York. 



Conducted by Professor C. S. Sargent. 



ENTERED AS SECOND-CLASS MATTER AT THE POST OFFICE AT NEW YORK, N. Y. 



NEW YORK, WEDNESDAY, JULY 5, 1893. 



TABLE OF CONTENTS. 



Editorial Articles: — The Preservation of Soil-moisture by Stiallow Tillage. .. 281 



Bestowal of Degrees by Harvard and Yale 281 



The Use of Flowers in Ceremonies Nineteenth Century. 282 



In a Mexican Garden C. C. Pringle. 283 



Botanical Notes from Texas.— IX E. N. Plank. 283 



Foreign Corresponcence: — Horticultural Education in Fiance. — II H. 284 



New OR LiTTLE-KNOWN Plants : — Xanthoceras sorbit'olia. (With figure.) 284 



Cultural Department : — Wild or Single Roses for Cultivation J. G. Jack. 286 



The Rock Garden ". T. D. H. 287 



Plants in Bloom J. N. Gerard. 288 



The Cultivation of Sweet Corn T. Greiner. 288 



Correspondence : — Dutch Bulbs in America ..W.E. Endicott. 288 



The Columbian Exposition : — Plants in Bloom Professor L. H. Bailey. 289 



Notes ' 289 



Illustration : — ^Xanthoceras sorbifolia. Fig. 41 285 



The Preservation of Soil-moisture by Shallow 

 Tillage. 



IN a recent issue we spoke of the necessity of surface 

 tillage for checking the waste of soil-water by evap- 

 oration. Referring to this advice, a correspondent asks 

 whether the stirring of the soil in hot weather does not 

 help to hasten the drying-out process rather than retard it. 

 Some of the most difhcult problems in physics are involved 

 in the movement of water in the soil, and no doubt there 

 are many things yet to be learned. However, we can ac- 

 cept some facts as established. Some six or eight years 

 ago there was a very general discussion by agricultural 

 writers as to the value of summer tillage, and there were 

 many experiments conducted in the state stations of New 

 York, Missouri and elsewhere. From these and from data 

 already gathered by European experimenters, it came to 

 be accepted as generally true that ground covered with sod 

 lost water more rapidly by evaporation than ground from 

 which all vegetation was removed, and that ground which 

 was stirred lightly at the surface lost less water than ground 

 which was simply kept free from vegetation. Of course, 

 results vary much in different kinds of soil, and there are 

 many conditions of drainage, porosity, percentage of water 

 to the soil, etc., to be taken into account, but the theory 

 that most students accepted was, that water rises readily 

 by capillary attraction through a compacted soil and it 

 passes off in vapor when it reaches the surface. On the 

 other hand, when the surface is stirred so that an inch or 

 two of soil is loosened the particles are so separated that 

 capillary attraction does not take place, and this covering 

 laid as a mulch on the compacted earth below prevents, to 

 a certain extent, the escape into vapor of the moisture 

 which arises to the point where the compacted earth had 

 been broken. 



In a recent number of the Pacific Rural Press it is stated 

 by General Chipman, of Red Bluff, California, that he once 

 left off cultivating his vineyard at a critical time, having 

 been advised that since the weather was hot the earth 

 which he turned up would soon lose its moisture, and that 



each cultivation would turn up a new layer to dry out. He 

 was told that the crust which had formed on top of his land 

 would check the water from passing off in vapor, but his 

 vines began to languish as cultivation ceased and he was 

 compelled to rig up a portable tank and haul water a mile 

 to assuage their thirst. In his dilemma he wrote to Pro- 

 fessor Hilgard, who reminded him, in reply, that if a dry 

 brick was laid on a wet sponge the brick would soon absorb 

 all the water ; if a dry sponge was laid on a wet brick, 

 however, the sponge wauld not absorb the water. Profes- 

 sor Hilgard compared the crust on top of the ground to a 

 brick on a sponge and suggested that the impacted surface 

 was rapidly taking up the moisture and letting it off in 

 vapor, that, therefore; the true course was to keep the 

 ground tilled on the surface. In General Chipman's lan- 

 guage, the surface pulverization acted like a woolen blanket 

 thrown over ice, its non-conductive quality helping it to re- 

 tain the moisture in the soil where it could be taken up 

 by the roots. 



Of course, weeds must not be left in the ground for they 

 pump up the moisture night and day. But, besides the 

 value of surface culture in destroying weeds, successful 

 fruit-growers find that the practice of pulverizing the sur- 

 face proves to be useful in preserving moisture. Market- 

 gardeners assert that light summer showers, in a compara- 

 tively dry time, are often injurious rather than otherwise, for 

 the ground at once hardens into a crust and the soil soon 

 gives out more water to the air than has fallen in the 

 shower. They, therefore, at once break up this crust and 

 arrest the evaporation. Of course, deep tillage would not 

 be advisable, even if it did not break the roots of the grow- 

 ing crops. All the ground that is turned up loosely or in 

 clods loses its moisture in the hot air. The true plan is to 

 stir the soil to a sufficient depth to make a light mulch. In 

 California vineyards fine slant-toothed harrows are used for 

 this purpose. Any implement which gives a light and 

 shallow stirring to the soil is effective. 



The importance of this matter will be understood when 

 it is remembered that in most of our agricultural lands the 

 evaporation throughout the whole season nearly equals 

 the rainfall, which directly enters the soil, and that it is 

 probable that during the growing season of most crops 

 evaporation largely exceeds the rainfall. Inasmuch as 

 plants take all their nourishment dissolved in water, it is 

 necessary for a full crop to husband the soil-moisture with 

 the greatest care. Hellriegel's well-known experiments 

 show that it is probable that the water exhaled by an 

 average Barley crop, together with that evaporated from 

 soil, is fully equal to all the rain which falls during the 

 growth of the crop, and that during several of the years 

 in which the experiments at Dahme were made the rain- 

 fall was wholly insufficient for the needs of such a crop, 

 not to speak of the large crops which can be raised in 

 some favored regions. Many European investigators", in 

 studying the question, have found that the rain which falls 

 on their agricultural fields does not suffice to produce large 

 crops, and for most temperate regions it may be consid- 

 ered as established that there is not enough of rain-water 

 for really good crops. • In view of these considerations, too 

 much care can hardly be taken in ordinary seasons to 

 check the evaporation of soil-water, so that it may be avail- 

 able for the use of orchards and vineyards and gardens. 



G.\RDEMNG and horticulture were honored last week 

 in this country in a manner which we believe is without 

 a precedent. On the same da)^ the two foremost universities 

 of the country. Harvard and Yale, conferred upon Frederick 

 Law Olmsted the degree of Doctor of Laws in recognition 

 of his creative genius as a landscape-gardener, which in all 

 parts of the country has continuously impressed itself upon 

 American civilization from the day, forty years ago, when 

 his conception of the Central Park, in this city, marked a 

 distinct era in the formation of great urban parks until the 

 celebration of the four-hundredth anniversary of the dis- 

 covery of America offered him the opportunity to show to 



