174 PLANT PRODUCTS 



hay so obtained show much variation. The amount 

 of albuminoids in the hays so produced are much greater 

 where phosphatic manures are applied, the best results being 

 obtained with both phosphatic and potassic manures. 

 Generally speaking, the hays of the higher feeding values 

 have been those obtained by both slag and potash, even 

 though, on the whole, the soil is towards the heavy side. 

 I^and, however, which is down to pasture, will only require 

 much smaller dressings, and occasional quantities of lime 

 and basic slag, giving about an average of three hundred- 

 weight of lime and one hundredweight of basic slag for 

 each year. This is for permanent pasture, which, by rights, 

 would only be on the heavier lands. A large amount of 

 weeds, especially buttercup and wild geranium, are indications 

 of excessive richness, produced by cake feeding, which has 

 never been supported by proper supplies of phosphatic 

 manures. For pasture lands, nitrogenous manures are 

 generally unsatisfactory, as sufficient nitrogen is supplied 

 by the droppings of the cattle. 



Sugar Cane. Sugar cane, like most of the sugar- 

 producing crops, requires considerable quantities of nitro- 

 genous fertilizers. Owing to its long period of growth, 

 these should be of the slow-acting type. For the ratoon crops 

 there is some difference of opinion as to whether the residues 

 of the manuring of the previous crop can be economically 

 replaced by more active forms of nitrogen. On the lighter 

 soils potash is also very necessary. The chemical activities 

 of the soil are greater in hot than in cold climates. The 

 decay of organic matter takes place with great rapidity in 

 hot climates, and even after ploughing-in green crops for 

 many years the accumulation of organic matter will not 

 reach the amount of a single green- manuring in colder 

 climates. As carbon dioxide is produced in the soil at a 

 greater rate than in cold climates, the general amount of 

 carbonic acid dissolved in the soil water will be greater, 

 in spite of the warm weather. Hence weathering of soil 

 will take place more rapidly in tropical climates than in 

 cold climates. 



