PUBLICATIONS ON AGRICULTURAL BOTANY IN FRANCE. 943 



Bourgue ^ has made a test of fertilizers on meadows. lie found that 

 the use of potash and phospbatic fertilizers increased the proportion of 

 le<juininous plants in mixed meadows from 10 to 20 and even 30 per 

 cent, depending upon the kind of fertilizer used, slag giving the greatest 

 increase. Nitrogenous fertilizers served to increase the proportion of 

 grasses. The results of four years' experiments with clieniical fertilizers 

 on beets are reported by Vivier.^ He states that the yield increased 

 aiul the densityof the juice decreased as the amounts of nitrate of soda 

 applied to the crop increased. Based on the sugar or alcoliol product, 

 applications of less than 800 kg. of nitrate of soda per hectare were 

 without benetit. Sulphate of ammonia was more profitable than nitrate 

 of soda. Superphosphates and muriate of potash gave contlicting 

 results, and are to be investigated further. 



General eultitre. — One of the most important investigations in this 

 line is that of Rauliu ^ on distance of planting. He gives curves show- 

 ing the variation in weight of the plant and of the yield per hectare. 

 In general it is shown that the total weight of the crop increases with 

 a decrease in the distance between the xjlants. This increase is less 

 rapid as the distances become smaller and finally a limit is reached 

 beyond whicli there is a decrease instead of an increase. The variations 

 depend largely upon the kind of plant, the development of its roots, and 

 the fertility ol*the soil. The author claims that for each species of culti- 

 vated plant there is within certain limits an optimum distance of plant- 

 ing which gives the greatest net return. This return depends not only 

 upon the total weight of the harvest, but also upon its value, the weight 

 of the seed, and the labor employed. The value of the product depends 

 upon its quality — the weight of the seed and proportion of starch and 

 gluten in cereals, the starch content in potatoes, and sugar in beets. 

 The proportions of these substances vary with the distance of i)lanring. 

 The investigation of this important question was left in an incomplete 

 condition by the death of Raulin. 



Attention is called to the notes by Grandeau* on the nutrition of 

 leguminous plants, and Naudin^ on the root tubercles of these idants. 

 The latter author maintains that some of the Leguminosa^ resist inocu- 

 lation, while others are indifferent to it. The author regards it as 

 extremely doubtful whether leguminous i^lants are benefited by vSymbi- 

 osis with bacteria, except indirectly by the improvement of the soil by 

 the nitrogen which the bacteria contain. 



Damseaux'' has studied the effect of sul])hurous anhydrid ui)on soils 

 and agricultural products. Metallurgical Avorks liberate large (juanti- 

 ties of this poisonous gas and its presence is shown by its effect ou the 



' Jour. Agr. Prat., 2 (ISIKJ), p. 862. 



"' Ami. Sci. Agron., ser. 2, aim. 2, 1 (18!»(i). p. 371. 



3Il)i(L, p. 394. 



■•Jour. Agr. Prat., 2 (1890), pp. 329, 371. 



6C()mpt. Keiid., 123 (ISHfi), p. 66*;. 



"Aim. Sci. Agrou., Her. 2. iinn. 2, 1 (189(i), p. 121. 



