266 ARTIFICIAL MANURES [chap. 



sufficiently, the nitrogen they collect from the atmo- 

 sphere, which mostly comes back to the land when the 

 herbage is grazed off, will be sufficient to keep up the 

 fertility of the soil. 



As to the time of application of artificial manures, 

 it has already been said that nitrates are not retained 

 by the soil, so that nitrate of soda and sulphate of 

 ammonia, which so readily changes into nitrate, can only 

 be employed as top-dressings in the spring, when the 

 crop already occupies the ground and is ready to utilise 

 them. Practically there is very little danger of even 

 the most soluble of quick-acting manures washing down 

 beyond the reach of the plant in spring or summer. 

 Consequently all kinds of fertilisers may be safely 

 ploughed into the ground from the month of March 

 onwards, except on the very lighest soils. The applica- 

 tion of spring manures is often needlessly delayed from 

 a mistaken apprehension that materials like super- 

 phosphate can be washed out of the land. Insoluble 

 fertilisers like the shoddies amongst the nitrogenous 

 manures, and basic slag amongst the phosphatic, should 

 be put on as early as possible, and may be ploughed or 

 dug into the soil in the autumn or early winter. 



Table XXV. at the end of this chapter gives a 

 number of analyses of the fertilisers with which a farmer 

 is most likely to meet, but it should be borne in mind 

 that many of these substances vary naturally in their com- 

 position, so that any particular sample can only be 

 properly judged by the analysis of that actual parcel. 

 In the United Kingdom, and indeed in all other civilised 

 countries, the vendor must supply an analysis of the 

 article he is offering for sale, which analysis has the 

 force of a guarantee. Given such analyses of a series 

 of suitable fertilisers, the farmer should then learn to 

 value them one against another. The most ready way 



