720 experimp:nt station record. 



The culture of autumn catch crops, P. P. Deherain [Ann. Agron., 

 21 {1895), No. 1, pp. 5-16; abs. in Compt. Rend., 120 [1895), No. 2, pj). 

 59-64). — The author had previously shown' that on soil kept entirely- 

 bare of vegetation the loss of nitrates through the drainage water was 

 very considerable. In practice, however, after the removal of a grain 

 crop, weeds and shelled grain gerininate and afford some vegetation 

 during the autumn. Hence he compared the amounts of nitrates lost 

 in the drainage water of land covered with grass and that on which a 

 crop of clover was growing. With grass the loss per hectare during 

 the autumn of 1893 was 13.78 kg., with clover 22.18 kg. This heavy 

 loss with both kinds of vegetation was attributed to the dryness of the 

 summer of 1893 and to the fact that when the autumn rains came the 

 plants were too feeble to appropriate all of the nitrates at their dis- 

 posal. In 1894 the drainage water from the grass pots contained 9.76 

 kg. of nitric nitrogen per hectare, that from the clover pots 15.03 kg. 



The office of catch crops is twofold, to take up nitrates during their 

 growth and to supply nitrogenous matter to the soil after being plowed 

 under. From the preceding figures grass was more active than clover 

 in preventing the escape of the nitrates. However, clover when plowed 

 under afforded 79.59 kg. of nitric nitrogen per hectare, while rye grass 

 furnished only 55.15 kg., thus showing the superiority of clover as a 

 crop for green manuring. 



An investigation by M. Breal confirmed the above results. He found 

 in 1 kg. of soil which received no green manure 141 mg. of nitric nitro- 

 gen; in the same amount of soil in which rye grass had been turned 

 under, 190.8 mg. ; and in the same amount of soil in which alfalfa had 

 been turned under, 289.4 mg. 



In 1894 vetch sown on stubble in August and plowed under late in 

 October or November afforded 78 to 90 kg. of nitric nitrogen per hec- 

 tare, which is estimated as equal to 15,600 to 18,000 kg. of manure. 



It was found that the dry matter of the roots of wheat contained a 

 larger percentage of nitric nitrogen than that of rye grass and much 

 more than that of clover. 



The effect of chlorin compounds on yields of peas, grains, and 

 potatoes, and on the starch content of potatoes, J. Schulte 

 (Magdeb. Ztg., 1894, No. 244; abs. in Centbl. agr. Ghem., 23 {1894), No. 

 10, pp. 706, 707). — The following chemicals were applied to peas, rye, 

 barley, and potatoes: Calcium chlorid, magnesium chloric!, sodium 

 chlorid, magnesium sulphate, and- potassium sulphate. None of these 

 chemicals reduced the yield of grain nor the percentage of starch in 

 the potato tubers. Indeed, the yield of potato starch on the plat to 

 which magnesium chlorid was applied was somewhat larger than on 

 the untreated plat. 



Fertilizer experiments on corn, oats, wheat, and grass, H. J. 

 Waters and E. J. Weld {Pennsylvania Sta. Ept. 1893, pp. 65-81). — 



»Ann Agron., 19 (1893), No. 7, pp. 305-338 (E. S. R., 5, p. 419), 



