APPLE-ORCHARD CULTURE 



413 



of injury to the trees from mice and other rodents and from 

 fire is greater in the sod than in the tilled orchard. 



(1) Sod Culture: In this system, fertilization is usually not prac- 

 ticed, the sod is thin and poor, and the grass is not cut. 



From the standpoint of the effect on the trees, this system is gener- 

 ally injurious in most orchards. The grass competes with the trees 

 for both water and nitrates. Practically always the soil in such orchards 

 contains less water and nitrates for the trees than the soil in orchards 

 which are cultivated and in which cover crops are plowed under each 

 year. Trees in such orchards usually have a yellowish foliage, the termi- 

 nal growth and spur growth are weak, the set of blossoms is usually 

 poor, the leaves fall early in the autumn, and the yields are small. Heavy 

 fertilization, especially with nitrogen for the trees and phosphorus for 

 the grass, is beneficial. The system is not recommended unless the soil is 

 unusually fertile, and unless some unusual supply of soil water from 

 springs, seepage, or some other cause is available most of the year. In 

 irrigated sections, its use might be permissible or even advisable in order 

 to increase the organic matter of the soil, especially if alfalfa were used 

 instead of grass. The grass or alfalfa, especially in bearing orchards, 

 should not be removed. 



(2) Sod — Hay, Cut, or Pastured: Under most conditions it will not 

 be profitable to cut hay from an orchard. Such a practice robs the trees 

 of both moisture and nitrates and should never be practiced in the 

 bearing orchard. In commercial orchards it will not pay to pasture 

 the land. Horses and cattle and even sheep will remove the foliage, 

 fruit spurs, and apples as high as they can reach. It is possible for a 

 farmer with two or three acres of orchard to use it as a pig pasture, but, 

 if more than three or four pigs per acre are placed in the orchard, they 

 may do considerable damage to the roots of the trees and the sod, unless: 

 care is taken to keep rings in their noses. In any case some protection, 

 should be provided around the trees, especially while the trees are youngs 



(3) Sod Mulch: This system differs from sod culture in 

 that an attempt is made to get a heavy growth of grass by 

 means of fertilization. The grass is cut at least twice during 

 the season and piled about the trees, while they are young, to 

 form a heavy mulch over the roots (see Fig. 162 6, c, /) , This 

 system may prove satisfactory, at least until the roots extend 

 out and occupy so much soil that enough grass would not be 

 produced to form a sufficient mulch. Certain experiments 



