December S, 1885. ] 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
607 
PLOUGHING IN GREEN CROPS. 
“ In your issue of October 8th, page 329, I notice it is 
stated with respect to green manuring that a green crop of 
White Mustard contains per acre half a hundredweight of 
phosphoric acid, a hundredweight of nitrogen, and a hundred¬ 
weight of potash; and that by ploughing in two successive 
crops the second crop adds considerably to the rich store of 
fertility already obtained by the first crop.” Thus writes 
“ Auricula; ” and he adds, “ I shall be glad to learn from 
whence the phosphoric acid and the potash are derived. If 
from the earth, then in ploughing in the crop you return to 
the soil only that which has been taken out of it.” To this 
we might be content to reply that phosphoric acid is a com¬ 
pound of one atom of phosphorus with fifty-nine of oxygen ; 
that the affinity of potash for oxygen is very great, and that 
out of 100 parts of the composition of plants upwards of forty 
parts are oxygen derived solely from the air and rain, and, 
therefore, that the ploughing-in of green crops is something 
more than “ a return to the soil of that which has been 
taken out of it.” But the query of our correspondent is by 
far too important to be dealt with thus summarily, and we 
gladly seize the opportunity to enforce strongly upon our 
readers the importance of a clear knowledge of the influence 
of natural laws upon our work of cultivating the soil. 
Fixed natural laws influence the phases through which 
the plants of the farm pass to full development. Of the four 
organic elements of our green crops three are always present 
in almost invariable proportions. These are oxygen, hydrogen, 
and carbon. Taking 100 parts of the composition of the 
plants of green crops we find that 93'55 parts consist of 
oxygen, hydrogen, and carbon, and they are all derived from 
the air and rain. Pray try and grasp the full significance of 
this wonderful fact, and you will then see how the gases of 
air and rain, in combination with other elements of fertility 
drawn from the soil, combine to develope and store in stem, 
branch, leaf, flower, and seed a rich store of nutriment, much 
of which enters the soil when we plough in a green crop. No 
doubt it is the general inattention to the influence of air and 
rain upon plant growth that tends to hinder the full recogni¬ 
tion of the value of green crops as manure, and yet it is con¬ 
stantly before our eyes. Said a worthy farmer to us once, 
“ I have frequently noticed that when a heap of Turnip tops 
is left to rot upon the soil there is sure to be a patch of 
growth there of a deeper hue and more robust growth than 
elsewhere in the next crop.” Yet he had not been able to 
comprehend and apply to practice this plain teaching of 
Nature. 
It is, however, by no means intended to infer that because 
the gaseous elements of the air in combination with heat 
contribute so largely to the substance of plants that the other 
elements are unimportant. Take, for example, two plots of 
poor land. Let them both be well stirred and sown with 
Mustard seed; leave one plot then to mature. Sow upon 
the other nitrate of soda at the rate of a hundredweight an 
acre, and mark the difference. The nitrogenous manure acts 
like a charm, causing the elements of fertility in air and soil 
to blend in happy combination, and the result is vigorous 
robust growth, in striking contrast to the comparatively 
puny growth upon the other plot. That this single applica¬ 
tion of nitrate of soda is sufficient is shown when we plough 
in the green crop and sow another. A yet stronger growth 
follows, telling us plainly that of all the elements of plant 
food necessary to insure robust growth nothing is wanting, 
the decay of the first crop in the soil storing it with nutri¬ 
ment. This fact is, perhaps, the best answer as to the value 
of ploughing in green crops. Agricultural chemistry is apt 
to be considered a dry subject, but let farmers only be made 
to see that the study of it confers knowledge and an insight 
into natural laws leading to results that are literally golden, 
and surely they will not be slow to acquire such knowledge. 
A disadvantage attending the use of artificial manures is 
slowness of action, but a soft green plant is comparatively 
so soluble that the elements of fertility are soon set free and 
are quickly available for plant food. Nor must we overlook 
a still more important consideration, and that is the economy 
of the process. Undoubtedly pure artificial manures mixed 
on the farm are preferable to farmyard manure on the score 
of economy, but green-crop manuring enables us to avoid 
manure bills, the only outlay being the cost of labour in 
ploughing and sowing. Doubtless this fact will tend to 
enforce attention being given to it more than anything else 
can do, for in the present agricultural depression we are 
bound by stress of circumstances to practise rigid economy. 
We are also bound to render and keep the soil fertile, our 
aim also being to see if by superior cultivation it is not pos¬ 
sible to wrest something more from the soil, to improve the 
quality as well as increase the bulk of our crops. Depend 
upon it the ploughing-in of green crops is a step in the right 
direction. To all doubters we say, Give the matter a fair 
trial next season. If you have land foul with couch grass 
watch for the first opportunity of stirring and clearing it in 
spring, then sow it with White Mustard at the rate of 20 lbs. 
of seed per acre; if poor, give a dressing of nitrate of soda, 
plough in the Mustard as soon as the plants are in full 
flower, and your land clean and fertile will be ready for a 
crop that will pay. 
WORK ON THE HOME FARM. 
Fine open dry weather has been turned to account for corn-threshing, 
and the work has been done well and quickly. All straw left iu the open 
air has been carefully stacked and thatched at once. No slovenly leaving 
about of straw heaps should ever be passed; this is a matter that has 
given us some trouble—so, too, has the too common tendency to leave 
implements about exposed to the destructive action of the weather. It 
should be an inflexible rule that no tools or implements should be left out 
after each job of work is done. Cleaning and painfiag should also be 
done in time. A man who is careful in such thin s will generally he 
found worthy of trust in others. Look well to water furrows on fresh 
ploughed land. As the ploughing or sowing of each field is finished the 
water furrows should be continued with a spade into the nearest ditch. 
Some judgment is required in the making of water furrows, especially on 
hill farms, serious injury frequently being done during heavy rain or in a 
thaw after snowstorms. It is bad practice to make water furrows from 
top to bottom of long slopes. The correct line to follow is a gentle 
diagonal one across the slope, and there should be enough of such furrows 
to prevent any serious surface washing. On open mixed soils very little 
care is required ; but there must be plenty of well-arranged furrows on 
heavy land and close silicious soils. See that the outlets of drains and 
all watercourses are open, and arrange that there shall be a regular 
periodical inspection of such places, as well us of pond banks. Upon one 
of our home farms we have several ponds down a valley that at one time 
were a source of annoyance from fractures in pond dams at flood times. 
We soon learnt the importance of making substantial dams high and 
wide, with a safety opening at what may be termed high water mark 
with a special channel to take flood water. Such work must be well 
done. Once get a fissure in a bank, a loose stone or two in a cascade, 
and down may go bank or cascade during some flood time in winter. 
Two seasons of severe drought have given point to the importance of 
water storage at this season of the year for cattle in summer. There are 
few farms where such storage may not he managed. We recently heard 
a complaint that a piece of land could not be drained because it was so 
low in the middle of it. We at once said, Excavate a pond in the lew 
place, drain into it, and you relieve your land of water and provide a store 
of it for summer. 
NITROGEN IN THE SOIL. 
Each of the elements required for building up the frame of animals and 
plants is of equal importance from a scientific standpoint, but in agricul¬ 
ture the various salts and substances which yield food for crops or for 
cattle must necessarily be valued according to their cost. There are ex¬ 
ceptions to this rule, no doubt. Gypsum is a cheap manure, but it has 
sometimes doubled the Clover crop, and kainit salts are comparatively 
cheap. Yet for some crops, especially Potatoes, in cases of a deficient sup¬ 
ply of potash in the soil, they have sometimts proved invaluable. In gene¬ 
ral, however, cost and efficiency are closely a-sociated, and as plants and 
animals are almost alike in their chemical composition the same rule as to 
