604 



FARMERS' REGISTER— EXPERIMENTS ON POTATOES. 



will recover their first fertility by being left long 

 enough to receive the natural supply of leaves 

 and stalUs of the plants which may spring and 

 grow upon them, thougli much of that supply 

 must necessarily be wasted by exposure. We 

 may then suppose that nature aids our operations 

 in a high degree, whether we work to dissipate 

 and waste our manures, or use the proper means 

 to increase the food of plants, and the productive- 

 ness of the earth. 



In attemjjting to devise rules for the most eco- 

 nomical and beneficial use of putrescent manures, 

 it is necessary to inquire what ingredients they 

 contam soluble in water, and therefore fit for tlie 

 present food of plants, and what are the successive 

 products made soluble by fermentation. More es- 

 pecially do we need the aid of the chemist for this 

 branch of the subject, and in tlie absence of that 

 aid, it must be very imperfectly treated. Never- 

 theless, though these soluble products may in 

 gi'eat measure remain as unknown quantities, our 

 reasoning respecting them will not be the less 

 sound. The great object with the farmer should 

 be to use all the ingredients of his manures as 

 soon as they are successively made soluble by fer- 

 mentation — and to avoid waiting for any until 

 they assume the gaseous form. 



The first effect of fermentation on hard and 

 coarse vegetable substances, is to break down their 

 texture, and make them more yielding and lender: 

 a subsequent effect is to make them soluble in wa- 

 ter — and the last is to convert them into elastic 

 gases. Many intermediate stages exist, and are 

 different in number and cliaracter according to the 

 substances acted on: but we may consider every 

 putrescent substance, or its principal part, to be at 

 different times in these three stages — 1. The solid 

 and insoluble. 2. The soluble — and 3. The aeri- 

 form. In the second stage only is manure useful 

 to growing plants — the first is certainly useless, 

 and sometimes hurtful — and in the third stage, the 

 manure is lost if not absorbed by the roots as fast 

 as it becomes aeriform. No one substance, how- 

 ever homogeneous, can pass with ail its parts 

 through these stages: its more putrescent parts 

 may arriv^e at the gaseous state, before the most 

 hard and inert have become soluble. Still more is 

 this diflerence exhibited in a dunghill, or a body 

 of manure composed of various substances, of all 

 grades between the most and the least putrescent. 

 Some wUl be passing away in gas, before the 

 woody fibre of others have begun to yield in the 

 least. But still there is a counteracting operation 

 in a well mixed bulk of various putrescent sub- 

 stances. The matters soonest fermented, though 

 they partly escape, yet they also act like leaven,"to 

 hasten the fermentation of less putrescent sub- 

 stances — and these in their turn perform the same 

 office for the slowest and hardest. This I consider 

 is the most valuable result gained fi'om mixing and 

 heaping manures: and it is obvious that the great- 

 er the variety of substances of different natures, 

 and the more intimate their mixture, the greater 

 will this benefit prove. The manure from stables, 

 and other still richer substances, if heaped alone, 

 will sufler greatly from the violence and irregular- 

 ity of the fermentation: but if carefully mixed 

 with the coarser and more inert contents of the 

 farm-yard, the fermentation of the last will be 

 quickened, and the first moderated. 



The foregoing exhibition of mj' views was pre- 



pared for publication more than two j'ears ago, 

 and has not since been changed, except in mere 

 form. This delay was caused b}^ an unwilling- 

 ness to present theoretical opinions so little sus- 

 tained by practical proofs — and with the intention 

 of endeavoring to jjresent some of those prools. 

 A partial and imperfect, though extensive and la- 

 borious course of experiments for this purpose, 

 was carried on, and reported in the Farmers' Re- 

 gister, Vol. I. page 136 to 142. With all the er- 

 rors and improper management in these j)ractical 

 operations, and the consequent losses there re- 

 ported, the fi\cts serve to support the theoretical 

 views here presented. Neither have my later prac- 

 tical operations, (which however have been neces- 

 sarily wanting in regularity and method,) induced 

 any change in these views — and for this reason — 

 that they consist jjrincipally in exhibiting errors of 

 opinion or practice, which may be known and 

 proved, without our being yet able to avoid them, 

 or being immediately thereby instmcted in the 

 most proper and economical course of manage- 

 ment. Later experiments and observations on the 

 fermentation and application of manures, and ad- 

 ditional views thereon, maybe hereafter presented: 

 but now it is ];roper for me to Avait to hear from 

 others on these subjects, before occupying more 

 space with m.atter which is readily admitted to be 

 crude and imj;erii?ct — and which can scarcely be 

 otherwise until the opinions and labors of many 

 persons are brought together to investigate and 

 discuss this most important branch of husbandry. 



EXPEKIMENTS IN THE CULTURE OF POTA- 

 TOES. 



Extracted from a Report on tlie Agriculture of tlie county of Car- 

 low, ill tlie [British] Quarterly Journal of Agriculture. 



The usutd mode of planting the potatoes is as 

 follows. The ilung being previously carted out in 

 small hea]:s and parallel rows at convenient dis- 

 tances, the ploughman marks out a drill, and in 

 the second course of his progress, Ibrms and clears 

 it perfectly; women with the potato sets in little 

 bags or aprons tied to their waists, take certain dis- 

 tances, oi lengths, of the drill, and in these deposite 

 the sets about 9 inches apart, in a single row. The 

 dung is forked over them by men, wlio have also 

 certain lengths of drill within their charge: the 

 ploughman, when not employed in opening drills, 

 covers up those already formed and ])lanted. The 

 good farmers afterwards roll the drills flat, but by 

 the ordinary class ol" liusbandmen, this operation 

 is neglected, as is the process of paring away the 

 clay previously to a complete weeding and earth- 

 ing up of the young plants, Avhich are too fre- 

 quentlj' covered up on their very first appearance 

 above ground. Two, and sometimes three, good 

 earthings take place, and, as far as fallowing and 

 cleaning the ground are in question, these earth- 

 ings are very beneficial; but as regards the pro- 

 duce, the advantage of them is problematical, as 

 may appear from the experiment of Mr. John 

 Robertson before alluded to. I consider the sub- 

 ject an interesting and important one, and shall 

 detail its particulars at length. 



Experiment 1. — Mr. Robertson marked off. on 

 an average portion of his potato ground, four drills, 

 twenty jards each in length; in two of these he 



