QUESTIONS 301 



As compared with the clean culture method, the fruit is smaller 

 (Fig. 210), the insects and diseases are worse, drouth may be more 

 harmful, and the growth of trees is less. 



Orchard tillage may consist of three or four operations. Plow 

 between the bearing trees in spring. Harrow soon after this to 

 prevent the drying of clods. Dig around the trees if the plowing 

 leaves the soil unturned. Watch the surface and prevent its 

 becoming hard or crusty. Use the disk harrow or other orchard 

 implement several times until midsummer. Then sow a cover 

 crop to remain all winter. 



Young orchards should be given such tillage as are required by 

 cabbage or potatoes. Such clean-culture crops may be grown 

 between the fruit trees for a few years. 



SURVEYS, PROJECTS, AND EXERCISES 



1. Manures. — Determine by a questionnaire (1) what legumes are grown 

 in the region for cover crops, or green manuring; (2) which ones require arti- 

 ficial inoculation; (3) stage of growth at which they are plowed under; (4) 

 other crops grown for green manure; (5) other sources of humus for soils; (6) 

 amounts of barnyard manure used; (7) crops following these applications: (8) 

 care of manure; (9) composting; (10) results of manuring; etc. 



2. Liming and Fertilizing. — Make similar questionnaires regarding the 

 liming of soils, the use of commercial fertilizers, and home mixing. 



3. Tillage practices may be studied by making an inquiry regarding fall 

 plowing, spring plowing, depth of plowing for certain crops, rolling, harrowing, 

 shallow intertfllage, etc. 



4. Growing crops as home projects may be so planned as to demonstrate 

 the effect of certain practices. (1) Crimson clover as a winter cover crop with 

 and without lime. (2) Special fertilizers on truck crops. (3) Deep fall plowing 

 compared with shallow spring plowing for the garden. (4) Deep and shallow 

 intertilktge for potatoes, for corn, for the orchard. (5) Manure and no manure. 

 (6) Barnyard manure compared with green manure. (7) Irrigation. 



5. Exercises in the laboratory should be tried to show floculation of clay 

 by liming; solubility of potash in wood ashes; alkalinity of wood ashes and 

 lime; acidity of certain soil samples; the amount of organic matter in certain 

 samples; solubility of acid phosphate; insolubility of rock phosphate; effect of 

 sulfuric acid on the latter; solubility of nitrate of soda, ammonium sulfate, 

 muriate and sulfate of potash, and other common fertilizers. (See details in 

 the author's School and Home Gardening.) 



QUESTIONS 



1. What are the four most important plant foods in soils? 



2. Discuss the sources of nitrogen for soils. 



3. How do legumes aid in supplying nitrogen? 



4. Give several methods of inoculation for legumes. 



5. Mention good legumes to use in the upbuilding of soils (1) summer annuals 



(2) winter annuals, (3) others. . 



6. What are some good methods of addmg organic matter and humus to soils.' 



7. Describe the making of a compost heap. 



