6 



Green Manuring. 



manuring by the ploughing in of intermediate crops of 

 leguminous plants, which not only cause the fixation and 

 accumulation of nitrogen in the soil, but supply the soil 

 with mineral constituents and at the same time, by the- 

 very deep penetration of the roots of the plants, especially 

 lupins, into the subsoil, enable the roots of succeeding 

 crops to go deep down in search of food. 



At a conference held in Dresden in 1891, M. Schultz 

 summed up the results of his experiments succinctly in the 

 following terms : — " With a limited stock of fatting cattle, 

 without buying any nitrogenous manures, by adding potash, 

 phosphoric acid, and lime, I have succeeded in fixing at the 

 expense of the atmosphere a considerable quantity of nitrogen, 

 by which I have been enabled to diminish by 50 per cent, the 

 expense of the production of cereals grown at Lupitz, or, which 

 comes to the same thing, to raise the average profit to 30s. 

 per acre, notwithstanding the unfavourable state of the 

 markets/' 



Details are given by M. Grandeau of M. Schultz's experi- 

 ments with no less than thirty species of leguminous plants, 

 with the object of discovering the most suitable for his pur- 

 pose. Among these were Lathyr^is clymenum, peas, white, 

 blue, and yellow lupins, mixed, in some cases, with other 

 plants, as rape, mustard, and winter turnips. These being 

 cut when in flower — the flowering period or soon after being 

 the proper time for ploughing in the green manure — were 

 severally analysed. 



Taking together the leaves and roots of six different 

 leguminous plants, the results of the analysis are given 

 below : — 



Name of Plant. 



Dry Substance 

 per Acre. 



Fixed Nitrogen 

 per Acre. 



I Equal to Nitrate 

 \ of Soda per Acre. 



Lathyrits dyineiutm 

 Peas - . . . 

 Mixed leguminous plants - 

 Lupins, white 

 Lupins, blue - 

 Lupins , yello 



Lbs. 



5,100 



7,140 



5.998 



6,273 



7,020 



5,090 



Lbs. 



154 

 198 

 165 

 162 

 171 

 130 



Lbs. 



1,000 

 1,267 

 1,028 

 1,039 

 1,081 

 847 



