Feb. 2s, 1918 



Humus in Mulched Basins 



513 



well with results stated by others (7, p. 128-129), but are necessarily 

 only estimates. 



The data obtained in the humus studies in mulched basins did not 

 indicate that there was any very appreciable accumulation of humus in 

 the lower soil depths due to leaching from the surface foot of soil. The 

 detailed data showed that most of the change in humus content took 

 place in the surface foot. 



RELATION OF HUMUS CONTENT OF THE SOIL TO ORANGE 



PRODUCTION 



Experiment I. — Picking records of the earlier basined trees in Experi- 

 ment I were obtained from the company on whose grove the experiment 

 was conducted, and are given in Table VI. 



Table VI. — Effect of different mulching materials on orange production. Experiment I. 



Picked May, igij 



This appreciable difference in fruit production of trees mulched with 

 alfalfa and manure, respectively, does not correlate with the humus con- 

 tent in the soil under the respective mulches, as may be seen from Table I. 

 The manured basins average a slightly higher percentage of humus than 

 the basins mulched with alfalfa. 



It will also be noticed in Table VI that the trees basined and mulched 

 with manure in March, 191 5, had previously produced slightly more 

 fruit than the trees mulched with alfalfa. 



When the oranges were picked in the spring of 1917, the color of the 

 oranges on the trees mulched with alfalfa was discinctly more golden 

 than the color of the oranges on the trees mulched with manure. 



Experiment II. — Individual tree picking records had not been kept 

 of the trees in the grove in which this experiment was conducted. Indi- 

 vidual tree picking records were obtained in the spring of 191 7 from the 

 company on whose grove the experiment was conducted. In this experi- 

 ment a row of trees was left unbasined and was manured, furrow- 

 irrigated, and cultivated in the usual manner. The amount of manure 

 per tree was the same as that put into the basins. 



The fruit production of the trees is given in Table VII. The number 

 of trees used in each set of mulched trees was from 13 to 15. 



