xt75mk655j4z https://exploreuk.uky.edu/dips/xt75mk655j4z/data/mets.xml   Kentucky Agricultural Experiment Station. 1940 journals kaes_circulars_003_350 English Lexington : The Service, 1913-1958. Contact the Special Collections Research Center for information regarding rights and use of this collection. Kentucky Agricultural Experiment Station Circular (Kentucky Agricultural Experiment Station) n. 350 text Circular (Kentucky Agricultural Experiment Station) n. 350 1940 2014 true xt75mk655j4z section xt75mk655j4z   UNI ERSITY OF K ii
  COLLEGE OF AGRICULTURE   · _
  EXt€nSi0n Division   I
ini i·. .
SLU it .
  THOMAS Y- COOPER, Dean and Director- Q   . .
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  CIRCULAR NO. 350 Q  
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  SAVE THE SOIL AND IMPROVE IT _i  Q2;-Z
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`_ Published in connection with the agricultural extension work carried on by co-  
gs, operation of the College of Agriculture, University of Kentucky, with the U. S. Depart-  §%frZi?*
i ment of Agriculture and distributed in furtherance of the work provided for in the  
  Act of Congress of May 8, 1914.    
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. PUBLICATIONS FOR REFERENCE
Any of the following publications on soils and crops will be sent free to
. citizens of Kentucky upon request addressed to the Director of the Experiment
' Station, Lexington, Ky.
Bulletin No. as
318 Adaptability of Red Clovers from Different Regions, to Kentucky. Oy
324 An Analysis of Clover Failure in Kentucky.
339 Black-Stem of Alfalfa, Red Clover and Sweet Clover. Cl
, 362 Tobacco Diseases in Kentucky. L]
. 371 Legtnnes in Cropping Systems.
` 379 Soil Management and Fertilization for Tobacco. ll
t 397 Soil Management Experiments. C
" Station Circular No. yy
Q 32 Nlarls for Liming Soils.
y Extension Circular N0. ll
{ 54 Soils. U
' 59 Liniing the Soil.
°- 77 Management of Tobacco Plant Beds. l`
_ 223 Loading and Spreading Mari. S
Q 230 The Production ol` \\'hite Burley Tobacco.
{ 212 Practices in Seeding Meatlow and Pasture Crops.
I 2»l7 Burning Lintestone for Agricultural Use. I
272 Soil Management for Kentucky:
 ‘ 292 Soybeans and Cowpcas in Kentucky. I
  297 The Lespede/as in Kentucky. i
3 3(ll Soil Erosion and Its Control.
  SI2 Growing .-\|l`alfa in Kentucky. (
  EHS Crimson Clover and Other Winter Legumes. (
I 336 Lessons on Farm Crops for l—H Club Members.
1 _ ‘
" Mimeographed reports on work on the Western Kentucky Experlmlml I
l Substation.
5 1
,· Leaflets
L Al Cover Crops.
yy A2 Lime and Phosphate for Kentucky Soils.
A3 Recommendations for the Control of Leaf Diseases of Tobacco.
j A-{ Contour Cultivation.
A5 Soil Tests for Need of Lime and Phosphate.
A6 Rapid Soil Tests.
. A7 Farm Manure. Its Value, Conservation and Use.
; A8 Hybrid Corn in Kentucky.
Q A9 Better Corn Culture to Reduce Soil and Plant—f0od Losses.
  A10 Cutting, Curing and Storing Hay.
§‘ All Field Crop Tests for Need of Lime and Fertilizers.
2 .»\l2 Recommendations for the Control of Wildhrc and Blackhre of
, Dark Tobacco.
P A13 Control of Tobacco Mosaic,
Q 1

 i .
     
  Circular N0. 350 V, A i
  SAVE THE SOIL AND IMPROVE IT   "' " ‘
W By GEORGE ROBERTS i . i.
  L. .
J { T  
  Soil conservation in its fullest sense means preventing as much    
  as possible all kinds of losses from the soil. The principal sources    
  of loss are erosion, the leaching of plant nutrients in the under-    
  drainage waters, and the removal of plant nutrients by crops. For    
  the state as a whole, the greatest loss is from erosion. However, if   _
yil there were no erosion, the losses from uncontrolled leaching and by    
  crop removal without the return of manure and crop residues § $5,;
  would soon reduce a fertile soil to a low state of productivity. i · i·=-
  Some soils, in their virgin state, are so deficient in mineral plant  
  nutrients that it is impossible to maintain satisfactory productivity yy g  
  unless the dehciencies are remedied. The mineral dehciencies of    
  Kentucky soils are generally calcium (lime), phosphorus and, in   »’»`·
  some cases, potassium (potash).  
  The Hrst step in improving soil is to supply the mineral plant  
  nutrients in which the soil is dehcient and then to grow legumes  
  and properly utilize the nitrogen they gather from the air in grow-  
  ing grasses, grain crops, tobacco, and other non-legume crops. There  
  can be no effective control of erosion without a dense ground cover,  
  even tho terraces and other engineering practices are used. Neitl1er  
  can leaching of plant nutrients be reduced without a ground cover  
  ready to grow when weather conditions are favorable. A protective  
is Covering is dependent upon a sufficient supply of plant nutrients.  
_ THE PREVENTION OF EROSION  
¤ Erosion causes the greatest loss from soils on sloping land, and  
  it may be very great even on moderate slopes. Fortunately this  
; t source of loss has been greatly stressed in recent years, and farmers yl;  
· i are becoming conscious of its seriousness. Erosion has caused enor-  
-   mous damage to soils in most parts of Kentucky. ]ust how much  
damage it has done it is not possible to estimate accurately, but it is  
A t the greatest cause of low soil productivity in the State. A great deal of  
  Uniform surface washing often occurs before the farmer is very  
` much aware of it. Too often he is not seriously impressed until t 
gullies begin to form. This stage usually occurs after a large part of  
  the top soil has been removed.  
F As stated. the most effective means of preventing erosion is keep-  
  ing a dense vegetative cover on the soil as much of the time as pos-  
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- - -~»-~»·»».. W .1...-     ,,,.,,,, _, __  

 Ll Kentucky Ex/cnsion Circular No. 350 1
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sible. A very large part ol the soils ol Kentucky has been so re-   yvi]
duced in [ertility that a cover cannot be produced that will pre- i Spy
— vent erosion, and lor this reason much of the cultivated area of the yjg
State is not even seeded to winter cover crops. po;
The best land cover is a vigorous grass—legume sod. For this rea»
son, Kentucky larmers should maintain livestock as much as pos- is
sible on pasture and hay. To get good results, the pasture and hay Us
must be ol high quality. This requires that the soil be well supplied Sw
with mineral plant nutrients and with nitrogen, which is most ba
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A A good pasture made on unproductive land at Western Kentucky Experiment Substation. ()
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- economically obtained thru legumes. The minerals most often de- V
ficient in Kentucky soils are lime and phosphate. Pasture and hay
T grown on soil dehcient in these minerals olten lack suflicient cal- ly
y cium and phosphorus for the proper nutrition ol` animals. Ani- H
; ` mals usually are 1lOt well nourished when led crops grown on impor- 1-
_— erislied soil, altho they may have all the leed they can consume. I
" Animals olten will reluse to graze pasture on soil deficient in mineral (
‘ nutrients when pasture on treated soil is available. I
  \Vith good pasture. the grazing period will be longer, and with l
  plenty of nutritious hay less grain will be required during the l
li . . . , , .
  Winter leedmg period, thus greatly reducing the acreage that Wlll  
5 have to be plowed for grain. lf the cultivated land is made pro- ‘
ductive, less acreage will be required, and it will produce a good i

   Save the Soil and Improve It 5     r 
  winter cover crop which can be used for fall, winter and early    
spring pasture, which will further reduce grain requirements. Acre        
  yields of corn can be increased by the use of hybrid corn, making   K;.  
  possible a futher reduction of the corn acreage.    
.l An outstanding example of the grass-livestock type of [arming   gi;   
  is in the Central Bluegrass region, in some parts of which as much   Y i`  
  as 80 percent of the land is in grass for pasture and hay. This     —
  system is also best for the production of both Burley and dark to- l  
cf bacco. This area has, in the judgment of the writer, suffered less   _  
K   from erosion than any other agricultural land in the United States, l   _  
V-l of similar topography and rainfall. That productive pasture of    
  protective sods can be produced economically on badly impover- l    
V.; ished soils in the State has been well demonstrated.     _  
  Mechanical means of controlling erosion are highly valuable    
  under many conditions, but none of them will prevent erosion ·i¥  2  
  unless the soil is made fertile and good cropping practices are used.  —_   Viii».V  
YJ Terracing and gully control practices are very important and are  
`Q treated in Kentucky Extension Circular No. 304.  
  Contour cultivation is effective in reducing erosion. ft is de-  
  scribed in Kentucky Agronomy Extension Leaflet No. Ll. Contour  
  cultivation means planting and cultivating across the slope. The  
  furrows and ridges made by contour cultivation check the flow of  
i water, causing more of it to enter the soil. \tVhen seeding and cul-  
  tivation are done with the slope, the furrows cause a rapid runoff  
  of the water, carrying with it much soil. It is very impressive to  
_. Q observe fields after spring planting and see the difference in erosion  
  on land planted and cultivated in the two ways. The amount of  
  erosion is often very great on land seeded to winter grain drilled  
A l with the slope, as compared with drilling on the contour.  
l The writer has observed serious erosion on land that was pre- CV; 
t pared for planting by rolling or dragging it smooth and on which    
a heavy rain fell before planting. Land smoothed in this way should  
‘ be planted on the contour at once before a rain comes, and im-  
tnediately cultivated to roughen the surface. Land planted to row  
crops on the contour should be cultivated after rains. to loosen and    
j roughen the compacted surface to reduce runoff. Erosion may be  
  lessened by leaving sod strips on the contour at intervals on sloping  
g land.  
A \Vhere sloping land must be cultivated frequently. strip crop-  
  ping is helpful in controlling erosion. Strip cropping consists in  
  laying out narrow strips or helds across the slope and alternating the  
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» 6 Kenlttc/cy Ex/mtsirm Circitlar N0. 350  
 
intertilled crops with thick-seeded crops or, better. having as many 1 hig
of the strips as possible in grass or other dense—seeded crop, always ‘ if <
T having the intertilled crops between thick-seeded crops except, of H0
course, when the intertilled crop is on the top or the bottom strip. th<
i ln other words, adjoining strips should never be used for imertilling NC
crops at the same time. (For types and details of strip cropping KW
see Farmers Bulletin l77fi, U. S. Department of Agriculture.) The
writer believes, however, that if there is level or gently sloping land SC]
y on the farm, it is better to keep the steeper land in a grass-legume H j
1 mixture for pasture and hay and produce corn on the level to gently SO
y sloping land ina short rotation or even in continuous culture. A two- Of
E year rotation of corn and winter grain can be used, with a legttme [O
y seeded grain to be turned under the next spring for corn. If the land pl
i can be limed, a mixture of sweet clover and lespcdeza is excellent. [O
  If only lespedeza is used, a winter cover should be seeded in the fall. C.
f ff the legumes thrive, they will fttrnish a large part of the nitrogen SL
i required by the corn and small grain, and using enough mamtre CI
Q to furnish potash for these crops may involve a considerable waste ;]·
  of nitrogen in the manure. It would be better to use fertilizer potash ]j
for the corn and winter grain along with the phosphate required. €~
 _` and to use the manure elsewhere, if needed, or perhaps use a limited ji
 N amount of manure for the corn. The Experiment Station has had C
  some excellent results with similar two-year rotations. I;
S SUPPLYING DEFICIENT MINERAL NUTRIENTS U
 _ lf any one plant ntttrient is deficient in a soil, it will limit crop
  growth, altho all others are present in sufficient quantities for max- t
t- imum growth. This fact is well illustrated in an experiment on one 2]
i of the Kentucky soil experiment fields where an untreated plot [
L yielded 575 pounds of tobacco per acre. Another plottreated with I
P limestone, potash and nitrogen yielded 580 pottnds. while another
plot with the same treatment pltts phosphate yielded MIO pounds. _
» l’hosphorus was the first limiting element. and its deficiency pre- A]
  vented the other application from having any effect. _
  Phosphorus is deficient in practically all soils outside the Blue- ‘
  grass area and in many places within the Bluegrass area. Most of
. the soils of the State need liming. The exceptions are soils that cou-
  tain limestone fragments in or near the surface soil. and soils
  in regions of marl deposits. particularly on slopes below marl out-
gi C1`O])s.
i Sandy soils are usually deficient in potash, bttt there is tlol mitch i
‘ sandy soil in lientucky. The soils of Kentucky generally have a  
E

      
  Save the Soil (md Improve II 7 A    
i? high content of potash, but potash deficiency will develop in any soil   A _i
  if crops are harvested regularly and crop residues and manure are i '_ ‘
T not saved and returned to the soil. This will be discussed under   . 9
  the heading "Conservation and Use of Crop Residues and Manure."  
Zi. No other serious mineral dehciencies are likely to occur in Ken-    J
  tucky soils if crop residues and manure are properly saved and used.    
  A plentiful supply of the mineral nutrients is absolutely es- 7  
  sential to soil improvement and conservation. As already indicated, i  
  a lack of any of them limits the growth of legumes necessary as a   3
  source of nitrogen for the non-legume crops. An abundant supply i
i-Q of nitrogen is required for high yields of general farm crops and    
  for the production of good grass for pastures and hay and for soil i  
g{ protection. The mineral nutrients are, of course, just as necessary   ·  
  for the non-legume crops as for the legume crops. The soils of the    
tig Central Bluegrass region are fertile because they contain a large -—i ` ‘
  supply of mineral nutrients. The chief difference between the min- I ‘
  eral content of these soils and the soils of other parts of the State is   2 `·._
rf the content of calcium and phosphorus, the elements supplied in ly  
  liming materials and in phosphate fertilizers. There is abundant  
  evidence in experimental work and practical farm experience that  
· if sufficient lime and phosphate are used on soils dehcient in these  
€ elements, and legumes are grown and properly used, such soils can  Q;
  profitably be made highly productive. (See Kentucky Bulletin 397, _.  
A “Soil Management Experiments.")  
; Excellent bluegrass sods have been economically produced on   ‘V'"  
i' the soil experiment fields at Campbellsville, Greenville, Princeton, V   
and Mayheld, on which tobacco of high yield and good quality has  
i been produced. (See Kentucky Bulletin 379, "Soil Management and  
  Fertilization for Tobacco.")  
ii Results from the outlying soil experiment helds in Kentucky  
show clearly that unproductive soils can be 1llZl(lC productive at com-  
paratively small cost by the use of lime and phosphate and the  
proper use of legumes and manure. Following is a summary of the  
results from the use of lime and phosphate on ten Kentucky soil ex-  
periment Helds, extending over periods of ten to twenty-six years.  
_ YVith one exception, these experiments were established on bad-  
5 ly depleted soils. The average yields include the low yields in the  
i CX1)(;‘]`i]]]C]][§_ r1`l](f Q]\'(f]`{lg(f   of COI`!] for the IZISL   )CZIl`S (lll  
2 the older helds was approximately 53 bushels per acre. The other  
  crops were correspondingly higher in the later years.  
_ r
ii  
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 8 Kentucky Extension Circular N0. 350 pl
Yields per Acre l ph
No. corn 1
N0. crops for Yield without Yield with {O1
crops which manure limestone or limestone and
Crops averaged was used phosphate superphosphate COT
Corn, bus. 163 106 29.2 46.7 PO
Soybean hay, lbs. 89 2218 3611 _
\Vheat, bus. 120 7.3 16.5 In
Mixed clover hay, lbs. 137 1301 3721 . UG
. . . . th
lhe average rate at wlnch limestone was used was about l ton or
in [our years. '1`he average annual rate lor superphosphate was equi-
valent to approximately 130 pounds per acre of 20 percent su-
perphosphate. Rock phosphate used on limed soil at double the
rate ol superphosphate gave practically the same results, except where
the soil was overlimed in the earlier years of the experiments. (See ]
Kentucky Experiment Station Bulletin 397.) The phosphate was P
. . . . . r'
applied in sufhctent quantity on corn or wheat for the rotation. » (
. . . . at
lhree and lour-year rotations were used.
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  ;_;~*»~,,;-iwipe-.—:~~¤;;¤;·=;w;·ag ~~.j¤¤:=‘T\¥,~`t·€s\’·. ·’¢<’f? .» ·-1;zl.:¤’;y;%w¢,="3¤»% f' zisiltsi  l
Bluegrassdegumc Mixture. Greenville Experiment Field |
Manure. when used, was applied lor corn at a rate equal to the
‘ weight ol the crops removed in the rotation the preceding yC2ll`
; (wheat grain excepted). Manure was used both where limestone and
phosphate were used and where they were not used. but ol course
at a heavier rate where limestone and phosphate were used, be-
` cause ol` the heavier yields ol crops.
\\'hen phosphate is used liberally (with lime where necessary).
it not only prohtably increases yield while being used, but a reserve
ol phosphorus may be built up in the soil which will be effective `
lor a long time without lurther application. l·`or example. on the
(Zampbellsville Experiment I·`ield. 900 pounds ol 16 percent super-

    
  Til wi; 
  Save the Soil and Improve lt 9     4
  phosphate per acre, applied once each three years on limed ground   is
Y for a three-year rotation of corn, wheat and mixed clover hay, was   , 1
1 compared with 600 pounds used in the same way. The extra 300   e
  pounds barely paid for itself over the twelve-year period (1919-1930}   _
  in which it was used. The use of the 900-pound rate was discontin-    
  ued after 1930. From 1931 to 1938, the average yields of crops where   '`‘’ Q
  the phosphate was discontinued and on check plots where no lime   ‘ .1
  or phosphate had been used were: Ei  
2   Corn, bus. Wheat, bus. Mixed hay, lbs. ? ‘ V
  No phosphate (check plots) 38.2 6.3 2558 V "
1 Phosphate used previously 60.1 15.9 4632 y     j
  Raw ground rock phosphate used at double the rate of super- y   ‘`1‘
  phosphate gave similar residual effects. Used at these comparative  
V; rates the rock phosphate supplied four times as much phosphorus    
  as the superphosphate. The experiment will be continued without   I ‘
  addition of phosphates to see what the results will be over a much   ‘ .
  longer period of time. (See Kentucky Bulletin 397, pages 361 to  
  367, for a fuller statement of these results. For further experi-    
  ments on the residual effect of phosphates, see pages 354, 374 and  
_ 1 380 of the same bulletin.)  
· On the average, raw ground rock phosphate contains approx-  
, imately twice as much phosphorus as an equal weight of 16-percent L  
. superphosphate, or 1.6 times as much as an equal weight of 20—per-  
. cent superphosphate. On some soils, two parts of phosphorus in ‘·‘’  
  rock phosphate is about as effective as one part in superphosphate. tl  ‘'~l
Z y On other soils the ratio required may be as great as 4 to 1. The i_  
relative effectiveness varies with the soil type and previous treat- V   
i_ 1 ment, particularly liming. lt is obvious that the price relationship  
between rock phosphate and superphosphate is an important fac-  
· tor in determining which to use. A much larger reserve of phos-  
phorus is built up in the soil [rom the use of rock phosphate than y   
from superphosphate when used on the same cost basis.  
Basic slag is another ellective source ol` phosphorus (see Ken-  
Lucky Bulletin 397, pages 363365 for tests). Bone meal is also an  
effective source of phosphorus.  
The eHectiveness of phosphorus in “colloidal phosphate" is  
similar to that of phosphorus in hnely ground rock phosphate,  
_ altho we do not have enough experimental tests to warrant a def-  
l   inite statement ol relative value.  
_ YVhen both limestone and rock phosphate are used, the lime-  
¥ stone should not be used too heavily, for heavy liming reduces the  
rl  
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 I
l
I
lf) Kmzlzzcky Ex/wision Circular No. 350
effectiveness of rock phosphate on some types of soil. Usually one gl
to two tons of limestone is sufficient for a period of ten to twelve Si
: years, when used with rock phosphate, except for alfalfa. If a farm- cr
er is unable to use both lime and phosphate where both are needed, te
. it is best, in most parts of the State, to use phosphate. However, gl
in the Purchase region it is usually best to use lime if only one ma- pi
terial can be used. This may be true of some of the more strongly ‘
i acid soils of the limestone area in southwestern Kentucky. Many w
of the high—phosphorus soils of central Kentucky need liming but p
  do not need phosphate. u
i THE GROWING AND USE OF LEGUMES S)
l (See Kentucky Bulletin 374, "Legumes in Cropping Systems"> 1*
L There can be no significant improvement of Kentucky soils
  without the growing and proper use of legumes. If not properly fl
F used, the ultimate result from growing them may be a further de- Sl
  pletion of the soil. It is believed that on the average soil, legumes S
1 take about one third of their nitrogen from the soil and two thirds il
  from the air. Thus if the part removed for hay weighs more than li
  twice as much as the roots and stubble, the soil may be left poorer L
' in nitrogen by growing the legume. Also, the percentage of ni- y l
  trogen in the roots is, on the average, less than in the tops, and de- 1
  cidedly so in cowpeas and soybeans. \Vhen soybeans and cowpeas l
  are removed from the land without the return of the straw or the
I manure made by feeding the crops, the soil is left poorer in nitrogen,
l except possibly when the soil is extremely deficient in nitrogen. (
  (See Kentucky Bulletin 3741, pages l5#l and 139). The richer the t
  soil in nitrogen, the less is the proportion of nitrogen that legumes i
  take from the air. Thus even red clover harvested may leave some
:_ soils poorer in nitrogen. i
. All the legumes make a heavy draft on the mineral nutrients of
i the soil. Alfalfa is especially exhaustive of mineral nutrients. A toll
of alfalfa contains about ~l(l pounds of potash. It is not uncommon
g to keep alfalfa on a piece of land five years or more. If 3 tons of hay
  a year for five years are harvested, it takes from the soil about 600
E pounds of potash. This draft will soon render any soil deficient in
  potash unless manure or potash fertilizer is used liberally.
ii lf legume crops are to increase the nitrogen in the soil and not
l rapidly deplete the mineral elements. the crops must be returned in
 y some way. lt is expensive to grow them to be turned under. lt is us-
; ually better to graze them or to feed them and carefully save the man·
t ure and return it. However, it often pays to turn under the hrst le-
ri

   Q    i   
  Save the Soil and Improve 1/ ll   r·
  gume crop grown on poor land as a means for quickly improving it.   i
fx Sweet clover used in this way is very effective. \tVhere a winter cover l . . V
`   crop is used on cultivated land, it is good practice to grow a win-   -
I ter legume, if possible, or a mixture of the legume with a winter  
  grain or rye grass. Crimson clover and hairy vetch are good for this   3 ..’i
purpose. ;· _
`   Legumes, with the exception of alfalfa, should have a grass grown   ` _"
  with them, when possible, to prevent leaching. Xalhere this is not l  
  practical, a winter cover crop should be used, as will be discussed 5 i
  under "Losses from Leaehing." Grass should be grown with alfalfa l A .
1 on sloping land, to prevent erosion. Seeding bluegrass with alfalfa    
A is an excellent way to get a good bluegrass sod. l   if
  A ton of average legume hay contains about 40 pounds of ni» l  
A trogen, which represents roughly what the crop, including roots and    
~‘ stubble, gets from the air, except the soybean and cowpea hays    
I generally contain more nitrogen than the whole crop gets from the ‘
air, because the roots and stubble of these crops are such a small    
part of the whole crop. Animals excrete, on the average, about l  
A three fourths of the nitrogen in the feed they consume, but a large  
·- part of it is in the urine. Therefore, the careful saving and use of    
i manure, including the urine, is very important in maintaining the  
nitrogen supply.    
THE CONSERVATION OF FARM BY—PRODUCTS  
The wastage of farm manure in Kentucky is very great. lt is  
estimated that manure produced annually in Kentucky amounts  
to about 16,000,000 tons a year, worth $¢l0,000,000, with manure  
valued at $2.50 per ton-a conservative valuation in terms of its ef- g  
' feet on crops. Probably 30 to 40 percent of the value of this manure  
is lost under prevailing practices. The average yearly excretion of    
. manure by horses and cattle is about 10 tons per 1000 pounds of live  
weight. Using fertilizer terms, a ton of average fresh manure con-    
tains about 10 pounds of nitrogen,   pounds of phosphoric acid,  
and 10 pounds of potash. Nearly half of the nitrogen and two-  
thirds of the potash are contained in the liquid excrement, as an  
average of horse and cow manure; hence the very great importance  
of conserving the liquid with bedding and so handling the manure    
as to prevent losses from heating and from leaching, which are great  
from manure as commonly handled. (See Kentucky Agronomy  
Extension Leaflet No, 7 on conservation and use of manure.)  
, A practice that is prevalent in parts of Kentucky and which  
should be discontinued is husking corn from the standing stalk  
  li  e
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