172 PERMANENT NURSERIES. 



The best time of the year to begin ploughing is soon after the 

 close of the summer rains : the soil is then soft and yielding, while 

 the sun is quite strong enough, or the cold at night great enough, 

 to destroy the vitality of the roots and underground stems torn up. 

 One or two women or boys should follow the plough and pick or 

 pluck out all stones and roots brought up to the surface. If the 

 land has had woody growth on it, the ploughman should be armed 

 with a light axe with which to cut through all roots sufficiently 

 strong to arrest the progress of his plough. A coulter (Fig 19, 

 C) fixed to the shaft of the plough, and strong enough to cut 

 through woody roots up to 1 inches thick, will facilitate and ex- 

 pedite the ploughing work very considerably. 



There should be at least two ploughings at right angles to one 

 another. 



The plough should be succeeded by the bullock-hoe (Fig. 19), 

 the size of which will be proportionate to the depth to which the 

 plough has penetrated. The hoeing, which should be repeated at 

 least twice, will shave away all the ridges necessarily left by the 

 Indian plough ; cut and break up the larger clods ; catch, cut or 

 tear and bring up to the surface nearly all the roots still remaining 

 in the soil ; level the ground by cutting away eminences and drag- 

 ging fresh earth into the depressions ; and thoroughly mix up with 

 the top soil any manure scattered over the surface. The clods are 

 still further reduced by means of a log-roller or special clod-crusher 

 drawn by oxen. After this it is advisable to hoe the soil over again. 

 in the same manner as on the first occasion. 



The soil should now be left to lie thus until the first fall of rain 

 has thoroughly soaked it, when it should be hoed over again in cross 

 directions. The result of this last hoeing will be that all the re- 

 maining clods, large and small, will be thoroughly comminuted, 

 the soil acquire a soft, uniform texture, and the surface be evenly 

 levelled. 



The procedure just described will answer in the very stiffest soils, 

 tor which indeed it is especially well adapted. Under exposure to 

 the air, the clods, drying up irregularly, crack and, to a very great 

 extent, crumble to pieces of themselves or become easily pulveris- 

 able. The comminution is still further assisted by the innumerable 

 particles of organic matter scattered throughout the soil and which, 

 absorbing oxygen and thereby increasing in bulk, become each a 

 centre of activity for loosening and breaking up the clods. 



If the soil is acid, the repeated turning up to which it is subject- 

 ed and the fine state of comminution to whicli.it is reduced by the 



