WHEN LIMING IS MOST PROFITABLE 

 Efect of Liming an Acid Soil 



231 



Treatment 

 (once m 5 years) 



Average value of 



crops per a^re 



per rotation t 



Average cost of 



hme and fertilizer 



per acre per 



rotation 



Net gam per acre 

 per rotation 





UnUmed 



Limed 



Unlimed 



Limed 



Unlimed 



Limed 



No manure, no fertilizer 

 Manure (8 tons per acre) 

 Acid phosphate (320 lbs 



per A ) 

 Complete fertihzer* 



$49.40 

 78.58 



67.80 

 87.76 



$61.40* 

 94.49 



8180 

 104.49 



16.00 



2 60 

 17 60 



$ S.OOt 

 2100 



7 60 

 22 60 



s 



14.96§ 



15.20 

 23 46 



1 7 00 

 25 87 



24 20 

 35 09 



* Application per acre consisted of a mixture of 240 pounds nitrate of soda, 480 pounds 

 acid phosphate and 240 pounds muriate of potash 



f Corn was rated at 40 cents per bushel, oats at 30 cents, wheat at 80 cents, corn stover 

 at $3 00 per ton, straw at $2 00 and hay at $8 00 



t The equivalent of 4 tons of carbonate of lime (pulverized limestone) was applied to 

 the acre m the 12 years Average cost, $3 00 a ton laid on the land 



g Increases were calculated not on the average of all the unfertihzed plots, but on the 

 average of two unfertihzed plots, one on either side of a treated plot 



* 



Liming Beneficial in Conjunction with Green Manuring. — 



An acid soil is unfavorable to the decomposition of green-manuring 

 crops and to nitrification. Moreover, during the decomposition of 

 green crops plowed under, acids are formed, causing a temporary 

 increase in the degree of acidity. For most crops the presence of 

 lime to neutralize these acids as soon as they form proves bene- 

 ficial. At the Virginia Truck Station best results were secured 

 with peas and beans when lime was used in conjunction with cow- 

 peas plowed under green or dry in the fall. For best results it is 

 desirable, therefore, to lime an acid soil before planting a green- 

 manuring crop, or in some cases, to lime just after the crop is 

 turned imder. 



When Liming is Most Profitable. — ^Liming is most profitable 

 when growing alfalfa. It is common to obtain increases from 100 

 to 600 per cent in the growth of alfalfa by liming acid soils, or to 

 secure a successful producing stand over absolute failure (Fig. 149). 

 Seventy per cent of the alfalfa failures studied in Wisconsin in 

 the period from 1912 to 1917 were due to acid soils. Liming acid 

 soils for alfalfa, particularly, may be the means of saving much 

 expense in hay production, since it is more economical to produce 

 twenty-five tons of alfalfa from five acres properly prepared than 

 from fifteen acres in need of lime. 



Just liming alone has proved about as beneficial as manuring 

 in growing corn on some very acid, black, sandy soils. ^ 



2 These soils are so strongly acid, farmers consider them barren. 



