132 AUSTRALIAN AGRICULTURE. 



Sea Weeds and Ferns. Potash, soda, lime, and 

 sulphates are got in sea weeds ; also in ferns, both of 

 which make desirable additions to the compost heap. 



Sawdust. Does best when mixed with a small pro- 

 portion of lime, say a bucketful to a load of sawdust. 



Mineral Manures. These include superphosphate, or 

 bone reduced by sulphuric acid, sulphate of ammonia, a 

 product of gas-making. Potash is imported in the form 

 of sulphate of potash and kanit, or salt of potash, the 

 value of each being dependent upon the potash contents. 

 Manures of the mineral kind give best results when 

 composted with the more bulky natural manures. 



Lime. Very plentiful in Australia, and of excellent 

 quality. It should be applied to the land separately from 

 other manures, and freshly slacked with water, that is, in 

 the form of quick lime, as a rule, where the land contains 

 much clay, or more than 10 per cent, of vegetable matter. 

 On thinner soils, air-slacked lime or bone dust answer 

 better. It is best to apply lime frequently and in small 

 quantities, to keep it near the surface and always active. 

 From one to three tons df lime to the acre may be 

 considered an average application. More may be applied 

 on very strong soil, and less on light land. Excellent 

 results often follow a first application of lime, but future 

 dressings may seem to fail to have the same effects. In 

 these cases, green crops might be ploughed in, and other 

 manures used, when, after a season, lime may again be 

 applied with profit, and to bring the fresh material into 

 active service by breaking them up for the use of crops. 



Green manuring the ploughing into the soil of 

 growing crops is one of the most certain, as it is one of 

 the always available means of enriching any moderately 

 good land. Amongst the plants specially available for this 

 purpose are peas, corn, buckwheat, oats, cotton, sorghum, 

 and the summer grasses. The effect of this treatment is to 

 supply vegetable matter in heavy quantity and in a form 

 most acceptable to the soil and the crop. It has the effect 

 of keeping the surface soil cool during our hot summers, 

 when crops rooting near the surface suffer badly from the 

 heated surface earth, and especially in sandy soils. The 



