70 ECONOMY OF FARMING. 



they leave behind in the soil much organic matter — in their leaves falling off at the 

 season of fruit — and frequently quite large roots ; and further, their thick condition 

 sets the field fully in the shade, and hinders the coming up of weeds and the useless 

 evaporation of the humus— therefore the following fruit of that time succeeds better 

 than after grass-kind of grain or knob and root-plants." — Tr.] 



13. A field, then, requires for the production of all kinds of fruits in a 

 course of years, so much the less manure, according to the frequency with 

 which pod-bearing plants, with thick roots, are cultivated with culmiferous 

 fruits. 



The culture of clover, luzerne and sainfoin, is therefore of the greatest conse- 

 quence, because they not only produce a very great proportionate quantity of fodder, 

 but also abstract but little humus from the soil, and by their remaining roots and 

 leaves decaying, they leave in the soil a great amount of organic matter which must 

 likewise be reckoned as entire manure with stall-manure. 



14. Because the herbaceous plants generally yield a larger organic pro- 

 duct than the weight of the humus which they absorb from the soil during 

 their growth : hence it is possible to keep the field in the same state of 

 fruitfulness if we do not bring back again a part of the product on the same. 



If plants lived only on organic matter, then must we, for that which we produce 

 from the fields and have not returned in manure, add vegetables grown elsewhere 

 to the same matter, whereby a gradual disappearance of vegetation would be 

 effected. 



15. The products of our fields are taken away from the same, either in 

 whole or part. 



16. Those products are wholly taken away which yield no manure on 

 the farm ; those in part from those fields to which is restored more or less 

 again in manure on the same. 



The grain-kernels, plants for commerce, &-c., which we sell from the farm, are wholly 

 taken from the field. But the grain that we consume on the farm itself, and the plants 

 for fodder, with which we support our beasts, are only so far taken from the fields as 

 a part of it is changed into animal substance, during the processes of digestion, or is 

 dissipated by means of the putrid fermentation. 



17. To keep the fields in the same state of fertility, there must be so much 

 manure restored that the mass of the humus may remain the same in a 

 course of years. 



18. But in order to return to the fields a quantity of manure propor- 

 tioned to their needs, it is necessary to know in what proportion the plants 

 need humus ; or much more how the quantity of the produ3t Is proportioned 

 to the consumption of the manuring substance in the soil ; and how much 

 they lose in substance consumed out of the field as fodder, and by putre- 

 faction. 



19. What we take away from the fields in any veg3table products, must 

 be restored again with other organic products, in the same degree as we 

 have taken away more r'lan the increase which the plants have appropri- 

 ated to themselves in inorganic matter. 



20. But because plants are of different natures, and the power to con- 

 vert inorganic matter into organic is not the same with all ; and because 

 the same plai't^ in different periods of their growth herein vary, therefore 

 the amount which must be restored for that which is taken, is not always 

 alike. 



