600 REPOET OF THE COMMISSIONER OF AGRICULTURE. 



covered with vegetation, lience the very great importance to Southern 

 farmers of resorting to that cheapest, quickest, and best method of im- 

 proving poor soil — green manuring. 



The dense covering, then, of pea-vines shades the soil, preventing 

 the escape of the soluble volatile elements of fertility with the vai)()r 

 of water. It renders the soil mellow, moist, and of equable tern porn - 

 ture, and, as a secondary matter, prevents the growth of noxious weeds. 

 The state of moisture under the shade facilitates the disintegi-ating 

 cft'ects of carbonic acid upon the constituents of the soil, prcpnring 

 thorn for plant-food, while darkness and moisture are conducive to ni- 

 trification. The decaying vegetable matter changes the physical text- 

 ures of tenacious clay, rendering it more pliable. Humus imparts to 

 the soil, more or less, its peculiar characteristics, increasing the porosity 

 of lieavy soils, letting in air and letting off vapor, and moistening dry, 

 arid ones by its great hygroscopic or water-vapor imbibing power. 

 Finally, ozone can. only form nitrates in the soil when organic matter 

 has passed into the comparatively stable condition of humus. 



The question of turning under the pea-vines green or after they have 

 been allowed to die on the ground is, like the vexed one of deep or 

 shallow plowing, governed by circumstances. They will ferment and 

 decompose more rapidly if turned under green, and it may be neces- 

 sary, when the land is needed for a crop as soon as decay may have 

 suiSciently progressed, to permit the planting. The advantage accru- 

 ing to the land by the longer mulch will far outweigh any possible loss 

 of fertilizing elements, if loss there be, and, besides, the plowing under 

 will be very much facilitated by the previous partial decay of so large 

 a mass of vegetation. 



When tlie turning under in the green state is necessary, the vines, if 

 of luxuriant growth, will first have to be leveled by a roller, or a har- 

 row reversed, teeth upturned, and a large, two-horse or sulky plow 

 used with revolving coulter attached. 



nOT-BEDS AND COLD FUAIMES. 



Not even as far north as Norfolk is '-glass" used by truck farmers 

 for the regular " forcing" of vegetables. The object aimed at is merely 

 to protect young plants from cold and inclement weather until the sea- 

 son arrives for committi^ng them safely to the open ground. The climate 

 at Norfolk is too severe to admit of the general use of cold frames for 

 tender plants, while south of Savannah bottom heat is never necessary, 

 and in this latitude only when a very light, warm, sandy soil, and a 

 protected locality is not available. During an experience of twenty- 

 nine years I have never had to resort to hot-beds for the preservation 

 of tender plants, as tomatoes, egg-plants, &c., never having lost a whole 

 bed by cold. More careful attention, sound glass, well-fitting sashes, 

 and tight frames are, however, indispensable, when cold frames in lion 

 of liot-beds are used, but the plants are of more stocky growth. On a 

 colder clay, or even a light loam, slight bottom heat is necessary to 

 carry tender plants through the winter months. In the warmer climate 

 of Florida both may be dispensed with, occasionally a slight screen of 

 any kind only being required. 



Evaporation and radiation of heat into space at night are the means 

 of preventing the accumulation of the heat of the sun upon the earth, 

 or all life would soon be extinct. When radiation of heat at night cools 

 the surface of the earth to a lower degree than the surrounding air, its 

 moisture is condensed in the fbrm of dew. If the cooUng of an object 



