178 VEGETABLE MATTER ESSENTIAL. 



and scanty as may be such products and such manuring of poor 

 lands, they very much exceed any substituted supplies ; and more- 

 over cost nothing.* 



That rotation of crops which gives most vegetable matter to the 

 soil, is best to aid the effects of marl recently applied. The four- 

 shift rotation is convenient in this respect, because two or three 

 years of rest may be given in each course of the rotation at first, 

 upon the poorest land ; and the number of exhausting crops may 

 be increased, first to two, then to three in the rotation, as the soil 

 advances to higher states of productiveness. But it is only while 

 land is poor that I would advise the four-shift rotation, with as 

 much as two years rest in the course ; or the entire exclusion of 

 grazing under any rotation. Both tend to make the fields foul with 

 both w r eeds and insects; and when the land has been under such 

 treatment for some 8 or 10 years, and has been made richer as well 

 as fouler thereby, it will be expedient to graze moderately and 

 judiciously, and to adopt a different and better rotation. 



After marling, clover should be sown, and gypsum on the clover. 

 On poor, though marled land, of course only a poor growth of 

 clover can be expected ; but wherever other manures are given, 

 and especially if gypsum is found to act well, the crop of clover 

 becomes a most important aid to the improvement by marling. 



* If there is one of the requisitions or accompaniments of marling 

 more insisted on than all others and both by my theoretical views and 

 practical instructions in all my writing on this subject it is the necessity 

 for providing organic (or putrescent) manure for all land in full proportion 

 to the calcareous earth supplied. Without this being done, not only will 

 the early effects of the calxing be small, but, in the end, the land will be 

 more completely exhausted of its actual organic ingredient, and conse- 

 quently and ultimately of its fertility, than if it had not been calxed. It 

 is not necessary, however, that all the required organic manure shall be 

 furnished from the stable and stock-pens or shall even be what is ordina- 

 rily termed manure. As much of this as may be available should be ob- 

 tained from these sources. But a much larger supply, and far more 

 cheaply, will be furnished by the fields themselves, in their vegetable 

 cover, whether of clover or weeds, suffered to grow and to die and rot on 

 or under the soil. This is the natural and the greatest source of supply 

 of organic manure to the calxing farmer and which he can increase to 

 any desired extent, by merely giving more time for the land to rest from 

 tillage, and to produce more of alimentary or manuring growths. 



But as often and as strongly as I have urged the indispensable necessity 

 for this course, scarcely any of my disciples have obeyed the injunction 

 fully and properly. Nine out of ten of all the farmers who have used 

 marl, and to great profit, still have drawn too heavily from their land, and 

 are lessening, instead of continuing to increase, the fund of productive 

 power in the soil, which calxing had made active. But with this important 

 truth they cannot be impressed. They cannot be persuaded that they arc 

 operating to exhaust their fields, while they still continue to derive from 

 them crops three-fold greater than formerly could be grown. 



