REPORT OF TEE CHEMIST 161 



SESSIONAL PAPER No. 16 



Series II. — The purpose in establishing this series of plots (M, N, O, P, Q, R.) 

 vfas to ascertain the relative degree to ■which certain crops reduced the soil's moisture by 

 their growth and, further, to gain information regarding the soil's moisture content 

 when the same crop is sown broadcast and in drills. With respect to this latter feature 

 it may be pointed out that the broadcasted crop may be supposed to conserve moisture 

 by shading the soil; while with the crops growing in drills, cultivation may be prac- 

 ticed with the same object. We wished to learn which of these was the most effective. 



The investigation was carried on between July 4 and October 10, the collection 

 of samples being made fortnightly to a depth of 14 inches. 



The crops (see table) were sown on June 27, and the cultivations of those sown 

 in drills were made on July IG and 27, and August 12. 



Unfortunately, owing to the initial moisture contents of Plots X and being 

 considerably less than that of the others, we are unable to compare the percentages 

 throughout the series. By comparing the losses or gains of one plot with those of an- 

 other, however, somxJ idea may be gained as to the relative effect on the soil's mois- 

 ture by the different methods under trial, and it is this plan we shall follow in con- 

 sidering the data of this series, 



Keference has already been made to the nature of the season. It will be noticed 

 frorn th(^ tnhnlated dnta that with the exception of the fortnight ending August 15, 

 no period (of two weeks) passed without an ample precipitation. This fact renders 

 the results, from the standpoint we are considering them, of much less value than if 

 the summer had been dry and warm. The results of this heavy rainfall, for instance, 

 increased the moisture of all the plots between July 18 and August 1, though at that 

 time they were carrying vigorously growing crops. 



Between August 1 and 15, slightly less than half an inch of rain fell, and it might, 

 therefore, prove instructive to make a comparison of the plots on that date. The 

 losses between July 4 and August 15 were as follows : — 



Plot M. — With a good crop of buckwheat the loss was 6'S9 per cent, or 166 tons per 

 «cre. 



Plot N. — This was in pease, but the growth was not very good, much of the land 

 bein? occupied by weeds. The loss was 3'7S per cent, or 90 tons per acre. 



Plot O. — Hairy Yetch, broadcast, good growth. The loss was 3'47 per cent., or 

 82 tons per acre. 



Plot P. — Hairy Vetch, in drills, and cultivated between rows. The loss was 2*29 

 per cent, or 59 tons per acre. 



Plot Q. — Soja Beans, in drills, and cultivated, not a heavy growth. The loss was 

 only 0'39 per cent, or 9 tons per acre. 



Plot B. — Horse Beans, in drills, and cultivated. The loss was 2*75 per cent, or 

 75 tons per acre. 



Without reading top much into these results we may safely conclude that the buck- 

 wheat extracted the most moisture, and this conclusion, as regards the effect of a grain 

 crop in drying out the soil, received confirmation by the data obtained from the growth 

 of a crop of oats as instanced in the Nappan experiments, hereafter to be discussed. 



Comparing the effect of Hairy Yetch broadcast and in drills, there is a notable 

 difference in favour of the latter method when it is desired to minimize the loss of 

 moisture. 



With Soja Beans, in drills, the loss had been insignificant, though during the 

 succeeding fortnight, August 15-29, the moisture fell off a little, probably owing to 

 increase in foliage. On this plot, however, the moisture content was remarkably con- 

 Btant throughout the whole period of the experiment. 



With the exception of the remarkable and unaccountable loss of moisture in the 

 plot with Horse Beans, the results of August 15 clearly indicate that much moisture 

 may be saved by sowing the crops in drills and cultivating between the rows from 

 time to time throughout the summer months. 



16—11 



