30 



Green Manuring. 



[APRIL, 



plants, such as rape, mustard, hemp, &c., are not now recom- 

 mended. 



Other plant food — i.e., potash, phosphates, and lime — must 

 be present in sufficient quantities in the soil to produce luxuriant 

 growth. If amply manured with kainit and basic slag, and also 

 with lime if necessary, the absence of nitrogenous manures 

 causes leguminous plants to become " nitrogen-hungry " and to 

 take up the free nitrogen of the air in the largest possible 

 quantities. But it is not only the nitrogen obtained from the 

 air which makes this method of manuring a cheap one ; it has 

 the further advantage that it is produced where it is to be 9 

 .employed, thus saving the labour of carting, especially where 

 fields are far from the manure heap. It is also valuable where 

 manure is scarce. 



The question of green manuring has recently attracted a good 

 deal of attention in Germany, and a summary of the points 

 which have been discussed has been contributed by Dr. Schnider 

 to the Praktische Blatter fiir Pflanzenbau (1904, Parts 2-7). 

 Dr. Schnider mentions that on light land in Germany, lupins, 

 the vetch, pea, and serradella are most commonly employed, 

 peas and vetches also on medium or heavy land, as well as 

 yellow and alsike clovers and horse beans. These may be 

 sown on stubble as an intermediate crop, or with corn, or on 

 land which would otherwise be left fallow. In the first case 

 when wheat, for example, is followed by barley or turnips, the 

 wheat stubble may be sown with some quick-growing leguminous 

 crop, which may be ploughed in during the late autumn. In 

 the same way, where from any cause it is found necessary to 

 allow the land to remain fallow, green manuring may be 

 adopted. It may also be used as a means of improving very 

 poor land. Dr. Schnider states that this method of fertilising is 

 probably most advantageous to hoed crops, particularly roots, 

 and also for oats. It is perhaps less suitable for wheat and 

 barley. According to experiments at Lauchstadt in 1903 and 

 previous years, green manuring with peas, beans, and vetches 

 after spring or winter barley gave good results with beets, but 

 was less effective with potatoes. 



Among the questions which have been investigated in recent 

 years are the time and depth of ploughing ; the effect of green 



