H VEGETABLE GROWING IN NEW SOUTH WALES. 



the surplus can escape so much more easily by run-off or gravitation. Again, 

 the crop will feel the effects of dry weather much more quickly when the 

 ploughing has been shallow. 



The deep breaking up recommended has thus a close connection with the 

 retention of moisture. 



Yet another effect of cultivation of the soil is the admission of air. 

 Unlikely as it may appear, air is as essential to fertility as water. If a soil 

 is compact, or if its interstices are filled with water or with fine silt, it 

 cannot contain the air that the roots of plants require, and that is necessary 

 to the minute organisms, called soil bacteria, that play an important part in 

 the preparation of plant-food. Moreover, it is possible for too much 

 air to be near the surface and too little below, with the result that while 

 seed may germinate satisfactorily, the plants may not do as well as they 

 should when the roots strike downwards. Cultivation aerates the soil, but it 

 must be carried deep enough for the plant roots to get all the air they require. 



The disturbance of the soil, too, has some effect upon its temperature. If 

 the connection of the surface soil with that just below is interrupted by the 

 plough or other implement, the great heat of the sun in summer, for instance, 

 cannot be so readily communicated to deeper levels. The most important 

 action in this connection, however, is the improvement in soil temperature 

 in spring as a result of cultivation. A soil saturated by winter rains will be 

 kept cold in spring by the rise to the surface of the water stored below ; 

 cultivation, however, will break the connection as just stated, and prevent 

 the rise of the waiter, so that the surface soil will dry to a certain extent, 

 and be the more quickly warmed by the action of the sun. The value of 

 this where early, quickly-grown, spring vegetables are desired for the market 

 needs only to be indicated. 



Soils that are of such close texture that water passes very slowly through 

 them are most unfavourable. Standing water damages the plants and 

 prevents bacterial activity, so that areas deficient in natural drainage 

 should not be used for vegetables. In fact, with extensive areas that 

 are suitable in most other respects, it is unlikely that the swampy lands 

 of New South Wales will require to be handled for a considerable time. 

 Where, however, the condition has to be dealt with, only deep, open, or 

 underground drains can be recommended. Their effect is to carry off the 

 surplus water, to permit air to pass through the interstices of the soil, and to 

 facilitate the drying up of some of the excessive moisture. 



.r-" 



Surface Cultivation. 



In addition to the deep cultivation so far kept in mind, it may be pointed 

 out that moving the top inch or two of soil has also important functions. 

 Generally speaking, surface cultivation is carried out in gardens for the 

 purpose of ^destroying weeds, but it also conserves moisture indeed, so 

 valuable and appreciable are its effects in this direction that, even in the 

 absence of weeds, the surface should be kept in a loose and friable condition. 



