Commercial Fertilizers for Various Crops 301 



the soil so that the legumes will do the rest, and if these are 

 well suppUed with these mineral fertiUzers, there will be 

 little need for other fertiUzing beyond what can be done 

 by the feeding of the legumes and the appUcation of the 

 manure thus made. 



Farming continuously with one clean cultivated crop 

 year after year, no matter how liberally the fertilizers are 

 used, will result in the depreciation of the soil through the 

 using up of the humus and the washing of the bare land 

 in winter. This has been the result in the cotton lands 

 of the South, and will be the result of single continuous 

 cropping anywhere. 



The soils of the cotton belt have lost fertility faster 

 through the washing of the bare land in winter than 

 through the summer cultivation. No land that has been 

 in a clean cultivated crop during the summer should be 

 left without a winter growing cover crop during the cold 

 season. This crop will take up the nitrates that form in 

 the soil and they can then be returned by turning under 

 the cover crop in spring. 



Fertilizers will always be more efficient on soils abound- 

 ing in humus or organic decay than in those that are 

 destitute of this, mainly because of the moisture-retaining 

 nature of the humus which causes the solution of the 

 fertilizers apphed. 



The bulletin of the Ohio Station has the following 

 remarks: ''At the prices at which mixed fertiHzers are 

 sold in Ohio, the attempt to furnish all the nitrogen, as 

 well as all the phosphoric acid and potash required to 

 produce increase in cereal crops grown in continuous cul- 

 ture has invariably resulted in pecuniary loss, although 



