238 THE farmers' handbook. 



American and English experiments are not the only ones which we have 

 to rely on in urging this work upon our wheat-growers. Experiments at 

 Geelong, Victoria, showed that just before sowing time a worked fallow 

 contained equal to 492 tons of moisture per acre in the top 18 inches of soil, 

 while a neglected fallow could only show 281 tons. 



The work was continued on a more extensive scale the following summer 

 at Longerenong Experiment Farm, the moisture-content of a worked and a 

 neglected fallow being carefully ascertained at different depths every month. 

 Certain land was ploughed and cultivated in September, one portion receiving 

 no further cultivation, and the other being worked in the same way and time 

 as other fallow land in the vicinity. On the 1st November there was already 

 a difference in the moisture-content, and by April the difference was marked, 

 the neglected fallow having in the first 4 feet 27'16 per cent, of moisture, 

 while the cultivated fallow had 32'7l per cent. As February and March 

 were months of good rainfall: the difference in the top 4 feet was not as 

 great as it would have been in a dry summer, but further tests showed that 

 the rains referred to had gone a good deal deeper than 4 feet on the culti- 

 vated portion, and remained there to nurture the succeeding crop. 



The effect of neglecting the fallow, as the above results clearly show, is to 

 allow the moisture which has been caught to escape again into the air. The 

 only way to prevent that is to maintain a loose surface, and thus put a lid 

 on the reservoir. 



There is another reason. A neglected fallow means a dirty fallow, in which 

 weeds add their part to the loss of moisture and plant-food, and spread their 

 seeds to the detriment of the next crop. 



When to Work the Fallow. 



As the object of working the fallow is to produce a loose mulch on th& 

 surface in order to prevent the evaporation of the soil-moisture, it can be 

 easily understood that the fallow should be worked in such a way as not 

 only to produce, but to preserve this loose mulch. 



Provided the soil has been ploughed when in good condition, it can with 

 advantage be left in the rough state as broken by the plough, there being no 

 necessity for immediate further treatment. But if the ground has been 

 ploughed when wet enough for the furrow to show a polished surface, it 

 will be desirable, in most cases, to harrow it as soon as it is dry enough to 

 crumble perfectly; otherwise it is likely to become so hard and lumpy that 

 the labour necessary to make a good seed-bed will be largely increased. 



The object of working the fallow early in the season is to keep a mulch 

 on the surface, so as to conserve the moisture in the soil beneath. As already 

 explained, mulches break the connection between the surface soil and that 

 beneath it. The more thoroughly this connection between the two sections 

 is broken the more effective will the mulch be. 



The plough, by cutting off a layer of surface soil and returning it loosely 

 and more or less inverted, completely breaks the connection between the two 

 sections, and in consequence makes a more effective mulch than any other 

 implement. Recently-ploughed land is, therefore, covered with the most 

 effective mulch possible. This is especially the case if a sod or the residue of 

 a green crop has been turned under. Until this mulch has been destroyed 

 by rain and other natural causes, nothing will be gained by working the land 

 and breaking down the rough surface. Indeed, to do this will be rather a 

 disadvantage; for it will have a tendency to re-establish the connection 



