CHOP PRODUCTION ON" FALLOW LAND AT SAN ANTONIO. 9 



Table II. — Absorption and run-off from rains in February, 1912, San Antonio Experi- 

 ment Farm — Continued. 





Fallow period 

 or crop. 



Samples taken on Feb. 26, one day after a 2.9-inch rain, when 

 the soil was already wet. 



Plat No. 



Average moisture, 

 content in 6 feet. 



Increase. 



Rim-off. 





7 days 

 befor9 

 rain. 



lday 

 after 

 rain. 



Per cent. 



Inches. 



Inches. 



Percent- 

 age of 

 rainfall. 



A4-1 



A4-2 



3 months 



Per cent. 

 15.2 

 16.8 

 15.3 

 16.7 

 15.5 

 16.3 



Per cent. 

 16.6 

 17.2 

 16.8 

 17.8 

 16.2 

 18.4 



1.4 



.4 

 1.5 

 1.1 



.7 

 2.1 



1.3 



.37 

 1.4 

 1.03 



.66 

 1.96 



1.61 

 2.54 

 1.51 

 1.88 

 2.25 

 .95 



55.3 



87.1 



A 4-3 





51.7 



A4-4 





64.6 



A4-5 





77.3 



A4-6 



Oats 



32.6 









Table II shows that the run-off from land that had been fallow for 

 several months was greater than from land plowed a comparatively 

 short time before the heavy rains. The proportion of run-off from 

 the second rain was somewhat greater than that following the first 

 rain, and the difference in run-off from plats fallowed for a short time 

 and from those which had been fallow for a longer time was more 

 marked. The run-off from the oat plat was materially less following 

 both rains than that from any of the fallow plats. 



ECONOMIC CONSIDERATIONS. 



The question of whether it is desirable to make a practice of 

 biennial cropping for certain crops must be considered from two 

 standpoints: (1) The effect upon the crop and (2) the cost of pro- 

 duction as compared with annual cropping. It must be remembered 

 that in the first case only one crop is grown in two years and that 

 fixed costs, such as the interest on the investment in land for two 

 years, must be charged against one crop. Under the conditions at 

 San Antonio, where plant growth continues practically the entire 

 year, making necessary the cultivation of the fallow to kill weeds 

 and maintain a mulch, the expense of fallowing is nearly, if not quite, 

 as much as that of growing a crop on the land. Other items, such as 

 the depletion of the humus and the possible ultimate effect on fertility, 

 are matters deservhig consideration in connection with the practice 

 of biennial cropping. It must be concluded, then, that even though 

 biennial cropping gave increased yields of winter oats at San Antonio 

 it is not necessarily desirable as a farm practice in growing that crop 

 there. In other words, the results of these experiments indicate 

 that biennial cropping is not to be recommended for the San Antonio 

 region, at least for cotton, corn, and oats. 



