14 



FORAGE-CROP EXPERIMENTS AT SAN ANTONIO. 



able to plant the sorghum-legume mixtures under irrigation in this 

 manner, and it is certainly not advisable to do so without irrigation. 

 Even with a thin rate of seeding the sorghum plants stool profusely 

 and have a tendency to crowd out the shorter leguminous plants. 

 So far, none of the tests with this method of planting have been satis- 

 factory. 



On a field which was fallow in 1909 and planted in Johnson grass 

 previously, a rate-of-seeding test for sorghum-legume mixtures was 

 made in 1910, to determine as far as possible in one year's test the 

 best proportion of each seed for the mixture. The row method of 

 planting was adopted and the rows were 3^ feet apart, the plats being 

 one-tenth of an acre in size. Sumac sorghum and Unknown cowpeas 

 were the varieties used in this test. Table X shows the results of 

 this test. 



Table X. — Yields of rate-of-seeding test of sorghum-cowpea mixtures, planted by the 



row method in 1910. 



Mixture. 



Sorghum 

 Cowpea . 

 Sorghum 

 Cowpea . 

 Sorghum 

 Cowpea. 

 Sorghum 

 Cowpea . 



Stand, 



plants 



in 50 



feet. 



95 

 90 



74 



100 



70 



105 



30 



100 



Number 



ol- 

 rul tings. 



} 



Yield 



per acre. 



Tons. 



4,: 



5. 15 

 4.02 

 2.35 



With all points considered, the second plat showed the best rate of 

 seeding, although a test of one year is not conclusive. (Fig. 1.) 



In the first plat the sorghum appeared to be a little too thick and 

 crowded the cowpeas, reducing the quantity of forage from them. In 

 the case of the last two plats the sorghum was entirely too thin, mak- 

 ing it rather coarse, but the cowpeas made an excellent growth. 



While the combination of sorghum and cowpeas is recommended, 

 especially for the irrigation farmer, yet it should be borne in mind 

 that extreme care must be exercised to secure the proper mixture. 

 If the sorghum is too thick, the cowpeas will not properly develop and 

 the forage will be little better than if the sorghum were planted alone. 

 On the other hand, if there is too great a proportion of cowpeas the 

 yield will be materially reduced and will prove a disappointment to 

 the grower. 



Sumac sorghum is undoubtedly the best variety to use when these 

 mixtures are planted, owing to its leafy character and slow growth at 



[Cir. 106] 



