66 



ONIONS ON MUCK SOIL 



type generally has a low capillary capacity, and, therefore, should 

 not be drained excessively. The water-table should not be lowered 

 more than is necessary to permit cultivation reasonably early in the 

 spring. This generally means lowering the water-table to a depth 

 of about twenty inches, varying somewhat with the character of the 

 soil. Open ditches are the best medium for first drainage opera- 

 tions. They may be cut considerably lower than the water-table 

 is to be maintained, so that the flood water will be quickly removed, 

 but it is a good plan to insert some sort of a check in the course of the 

 ditch when the water-table has been sufficiently lowered to hold it 

 to that level. 



Areas which have not a natural water supply will generally justify 

 irrigation if they are devoted to truck crops. One of the great 

 factors in cutting down yields of truck crops on many areas of muck 

 soil is deficient water supply. When muck dries out, it shrinks 

 excessively and large checks are formed. If these are not kept 

 filled by pulverized muck, or by frequent tillage, the loss of water 

 will go on to considerable depths. The dry muck is a very effective 

 mulch so that this condition can be readity controlled. These facts 

 have a special relation to the tillage of the onion crop, which, owing 

 to its limited root system, is very quickly subject to a deficient 

 moisture supply in the surface foot. 



Composition of Muck Soil. Muck soils are made up chiefly of 

 organic material. They are characterized by being very rich in 

 nitrogen, moderately well supplied with phosphoric acid, and rela- 

 tively low in potash. The following analyses of a number of areas 

 in the state are sufficiently representative: 





Organic 





Phosphoric 





Calcium 





matter 



Nitrogen 



acid 



Potash 



oxide 



Redwood 



88.7 





.27 



.15 



6.2 



Red Creek 



85.5 



2.6 



.26 



.18 



4.2 



Oak Orchard 



65.5 



L8 



.28 



.26 



4.4 



Florida 





2.2 



.32 



.36 



2.6 



South Lima, virgin . . . 



83.4 



2.4 



1.9 



.09 



6.3 



South Lima, cultivated 



82.5 



2.4 



.48 



.44 



5.9 



It will be readily recognized that muck soil requires fertilization 

 with potash, and this practice has been very generally followed. 

 The presence of large quantities of nitrogen would suggest that 

 nitrogen fertilizers may not be beneficial. But in practice, it has 

 frequently been found that a small amount of nitrogen, especially 

 in the early stages of tillage, is helpful. This is due to the fact that 



