66 



Use of Waste Organic Substances. [may, 



securing maximum crops ; the manuring and cultivation adopted 

 would give much better results if more water were present, pro- 

 vided, of course, it had no depressing effect on the soil tempera- 

 ture and air supply. This question will assume even greater 

 importance as the necessities of the towns compel them to sink 

 more and deeper wells in the country. Already in many 

 districts the water level is lower than it was ; shallow wells are 

 in consequence * left dry and have to be deepened, and the 

 supply available for the fields promises to be still further cur- 

 tailed. Proper cultivation and the application of organic 

 manures are two good ways of conserving the water supply. 



Organic matter is not indispensable ; crops can be grown on 

 an experimental scale without it. But the advantages of having 

 some present and of replacing it as it disappears from the soil 

 in consequence of bacterial and other actions are well recog- 

 nised ; the farmer uses dung, and the manure manufacturer 

 frequently puts organic matter into his compound fertilizers. 



There are a number of waste products, used at present only 

 in special branches of farming, some of which deserve a more 

 extensive trial. This paper deals with certain substances used 

 in the hop gardens of Kent and Surrey, but there is no funda- 

 mental reason why their use should be restricted to hops, and 

 the writer has seen some of them applied with great advantage 

 to other crops. Nor is their use confined to a particular type of 

 soil ; they are generally applied to light chalky or sandy land, 

 but this is by no means essential. 



There are, however, certain drawbacks with regard to pur- 

 chasing. The supply is somewhat irregular, and bulks are often 

 not uniform ; it is difficult to draw a representative sample for 

 analysis, and dealers often decline to give any guarantee as to 

 composition. Competition from other quarters may force prices 

 up too high, difficulties attendant on sanitary regulations may 

 do the same, or they may act in precisely the opposite direction. 

 There is no uniformity of price ; indeed, prices vary in neigh- 

 bouring districts in an apparently haphazard - way, and the 

 personality of the buyer is an important factor. Little infor- 

 mation is obtainable as to the relative manurial value of the 

 various substances ; the usual pot experiments are not quite 

 satisfactory, because sufficient account can hardly be taken of 

 the power to hold up water. It seems certain, however, that. 



