1836.] 



F A R M E R S ' REGISTER 



609 



too abundantly it becomes exhausted and dried, 

 and bears only that which is small and misshapen. 

 The difference between annua] and perennial plants 

 is, that the former die as soon as the process of 

 fructification is completed; while the latter preserve 

 their leaves green and theirroots fresh, for the pur- 

 pose of absorbing new portions of nourishment, to 

 be deposited in their vessels for food when the re- 

 turning warmth of spring shall cause them to re- 

 quire ir. 



M. Matthieu de Dombalse, one of our most en- 

 lightened agriculturists, has confirmed by experi- 

 ments, the doctrine I have here advanced. On the 

 26th of Jane, 1323, at the time of flowering, he 

 selected, within a small space, forty wheat plants 

 of equal size and strength, each having three 

 stalks bearing heads; he palled twenty of the 

 with all their roots, and left the rest to com- 

 plete their fructification. Having carefully freed 

 the roo s of those he had taken up, he 

 cat the stalks two jpches above the ba.se, and dried 

 separately the roots, and the stalks surmounted by 

 their heads. 



The. roots and. the portion of the stalks remain- 



ing with them weighed, grains 

 The stalks, heads, and leaves, - 



the grass has been left to go to seed, it will be ne- 

 cessary to supply the earth with manure before it 

 will yield a good return. As those plants that are 

 cut at the time ot flowering do not exhaust the 

 soil so much as those that remain for seed, the be- 

 lief has arisen among farmers, that before the pe- 

 riod of fructification, they are nourished by the 

 constituent principles of the surrounding air and 

 water; but that during the time of the. formation 

 of the. seed, their support, is almost wholly derived 

 from the earth. But this opinion will not hold in 

 regard to all plants; lettuce, turnips, tobacco. 

 woad, endive, cabbages, and onions, exhaust the 

 soil greatly, though they are gathered before pro- 

 ducing seed. Potatoes, though they produce but 

 Jew seeds, impoverish laud more than almost any 

 Other vegetable. Plan's raised in a nurs ;r 

 afterwards transplanted, exhaust the soil in which 

 they spring mare than the one in which they com- 

 plete their growth. 



Thus we see, that daring the whole time of their 

 ation, plants derive their nourishment from 

 tlic air and from the substances contained in the 

 earth; but if they are mown at the time of flower- 

 ing, they leave in the soil their roots and portions 

 of their stalks, which restore to the earth nearly 



as much as they received from it; while, if they 

 remain uncut till they have completed their course, 



they return little or nothing to the soil to compen- 

 sate it for the nourishment they have received 



from it. 



It is weil known to farmers that ploughing in a 

 i crop of any kind whatever, prepares the 



soil for producing we'd without any other manure; 



since, by this process all that the soil has yie 1 , .' ,,,._ and bear(1 



is returned to it, with some additions resulting n... • ' 



from the decomposed principles oi air and water, i 



which are contained in the plants. 



In order fully to understand this doctrine, which 



appears to me of great importance to agriculture, 



it is necessary to consider the successive changes 



which take place in annua! plains during their 



growth; first, they produce <rreen leaves, which, 



by coming in contact with the air, receive from it 



the principles of which I have spoken; subse- 



quenly the stalks increase in size and number, and 



are covered with numerous leaves, which absorb 



from the atmosphere a degree of nourishment 



suited to the increasing wants of the plants; the 



strength, fulness, and depth of hue of the leaves 



and the stalks, particularly of the latter, increase 



in proportion to the richness of the soil. 



This stale continues till after the period of flow- 

 ering, when a change, worthy of note, takes 



place; the roots dry up, the stalks wither and 



change their color; and when fructification is at 



length completed, both roots and stalks have be 



- 647 



- 1946.5 



Total, - - - 2J03.5 



On the 28th of August, the time of harvest, he 

 plucked up the twenty plants which had been left 

 for seed, separating the roots and cutting the stalks 

 as of the first; of these the weight was as follows : 



Graius. 



R ,ots, ..__._ 419.53 



1318.75 

 1025.69 



Total, ----- 2763.97 



During these two months, the roots and 

 the portions of stalks adhering to them 

 had lost, ----------- 237.52 



The stalks, head, and leaves had lost - 624.67 



Total loss, ----- 882.19 



But as the seed weighed 102-3.09 grains, the 

 whole had increased in weight 160.47 grains, 

 Troy. From this experiment we may conclude, 

 that the juices contained in the plants, at the time 

 of flowering, contribute to the formation of the 

 grain in the proportion of fofln-?, and that the ex- 

 ^c?± of the weight of the grain which is T ^sV-- 

 arises from the nourishment which the plants ab- 

 sorb from the air or soil, during the two months 

 of fructification. 



If the wheat is mown when in blossom, it leaves 



in the earth, to be converted into manure, a quar- 

 come mere skeletons, which answer but little, pur- j ter part of the weight of the plant; but when it is 

 pose, either for nourishing animals or manuring reaped after having come to maturity, there re- 

 earth. During this period of vegetation, what mains only one-seventh; and this last residue is 

 becomes of the juices that were so abundant in worthless as manure in comparison with the first; 

 the roots and stalks? They have been consumed \ this contains almost nothing I ut carbon, while ihat 

 by the formation of the seeds. It is undoubtedly , is rich in juices and in decomposable matter. Thus 

 the case that plants still continue, during fructifi- we see that those plants which form seeds exhaust. 

 cation, to absorb some portion of their nourish- die soil most, because, for all they have received 

 rnent from the air and soil; and this assists in the they return nothing but their dry roots and stalks; 

 formation of their seeds: but by far the greatest while those, that are cut when green give back with 

 share of the formation of these is owing to the de- their roots and stalks what, they have drawn from 

 posites contained in the organs of the plan's. soil, and a part of that which they have drawn 



The same holds true ot' perennial plants; and it from the atmosphere. 

 may be observed, that when a tree produces fruit j The nutritive principles contained in the soil pass 



Vol. Ill— 77 



