SOYBEANS FOR MASSACHUSETTS 13 



drought resistant, the\' will also make a good growth on soil that is too wet for 

 corn. While the soybean is less acid-sensitive than clovers, it responds to lime 

 on acid soils, and fails to thrive in cases of extreme acidity. Soils having a reac- 

 tion below pH 5.5 should be limed before planting to soxbeans. 



Preparation of Seed Bed. — A firm seed bed with a la>er of fine loose soil at the 

 top will insure the best results. The ground can be plowed either in the fall or in 

 early spring, and disk-harrowed just before planting, to kill all weeds that have 

 started. A firm seed bed can then be obtained with a smoothing harrow. 



Fertilizers. — Stable manure can be used to advantage in starting the soybeans, 

 but it should be supplemented with 300 to 400 pounds of superphosphate and 50 

 to 75 pounds of muriate of potash. A small amount of nitrogenous fertilizer is 

 advantageous in starting the soybeans when manure is not used. 



Inoculation. — Soybeans, if well inoculated, gather much of their nitrogen from 

 the air through the nodules on the roots. When seeded for the first time in a 

 field, inoculation is necessary. Commercial so>-bean cultures can be used, or 

 soil from an inoculated field can be spread at the rate of 250 pounds per acre. 



Time and Depth of Seeding. — As soybeans germinate ver\- slowly in cool weather, 

 they should not be planted earlier than corn planting time. The>' are somewhat 

 more sensitive to frost than is corn. Seedings may be made as late as July 1 in 

 Massachusetts if the soybeans are to be used for hay, soiling, or green manure. 

 Maximum yields will be obtained from seedings made soon after danger from 

 frosts has passed. 



In light sandy loams and sands, soybeans ma>- be planted 3 to 4 inches deep. 

 In heavy loams and clays, a depth of about 1 inch gives best results. Differences 

 in emergence due to depth of planting were brought out in a supplementary 

 experiment. 1 From a sandy loam soil plants emerged without difticulty when 

 planted as deep as 4 inches, whereas seedlings had difificulty in emerging from a 

 clay soil when planted as deep as 2 inches. The experiment also showed that 

 seedlings emerged much more rapidly with an air temperature of 72°F. than 

 at 61°. 



Method and Rate of Seeding. — Soybeans can be sown in rows wide enough to 

 allow cultivation, or in close drills, or broadcast. Under conditions where weeds 

 are a factor, cultivation may be necessary- for weed control. The rows are 

 usually placed 28 inches apart on good soil and from 36 to 42 inches apart on poor 

 soils. The grain drill can be used for sowing either in wide rows or close drills 

 by covering the seed cups to adjust the width of row. Corn planters can be 

 used for planting soybeans by using plates adapted to this purpose. When 

 grown for hay in rows wide enough to allow cultivation, the plants should be 

 spaced about one inch apart in the row. This requires from 20 to 75 pounds of 

 seed per acre, varying with the size of seed and the width of row. If a drill or 

 planter is not available, the seed may be broadcast and covered with a harrow. 



Weed Control. — It is not advisable to attempt to grow soybeans in a heavy 

 infestation of witch grass, though it can be done by planting them in wide rows 

 and cultivating them just the same as drilled corn. Nor is it advisable, as a rule, 

 to attempt to grow them in land so wet, heavy, and cloddy that a spike tooth 



'Reported in a thesis entitled, "A study of varietal and cultural factors affecting the stand and 

 yield of soybeans," submitted by R. E. Stitt to the Faculty of the Graduate School of the Massachu- 

 setts State Col'ege for the master of science degree, 1930. 



