flow to Find Defects. 37 
fertilization, which are out of proportion to the returns they are 
able to make. 
Rise of Ground Water.—Good fruit lands are also occasion- 
ally rendered defective by the rise of the ground water toward 
the surface so that only a shallow layer is left for root extension 
—the evil being aggravated by the fact that a temporary fall of 
the ground water induces deeper rooting, which a subsequent 
rise of the water destroys, and decay of the roots ensues. This 
trouble has occurred over large areas where excessive irrigation, 
or the course of leaky ditches, on higher lands, has filled the 
lower levels to such an extent that there is actual outcropping 
of swamps in the swales. The cure for these conditions is, 
obviously, drainage, which it is not always possible to secure 
at a warranted outlay. 
Alkali—Connected with this rise of the ground water the 
alkali evil may intrude. ‘But little trouble arises from this cause 
in the high-lying, sandy tracts, where irrigation or the natural 
rainfall carries the soluble salts annually into the country drain- 
age; but in the low-lving and less pervious soils of swales and 
valley troughs, which are at the same time intrinsically the 
richest in available mineral plant food, the accumulation fre- 
quently causes considerable trouble and difficulty.* 
Prospecting for Soil Defects—The University Experiment 
Station at Berkeley, undertakes to advise planters concerning the 
character of the land they propose to use. For subterranean 
prospecting, Professor Hilgard commends a steel rod not less 
than a quarter of an inch in diameter (round or square, prefer- 
ably the latter), well pointed at one end, and provided at the 
other with a stout iron ring for the reception of a stout cross- 
handle, such as is used for post-hole augers. With such a prod, 
or sounding-rod, not less than five feet in length, the explora- 
tion of the subsoil for hard-pan or dense clay layers becomes a 
matter of a few minutes. It is easy also to detect thus the pres- 
ence of underlying layers of quicksand, gravel, or other loose 
materials through which irrigation water would waste, or which 
would prevent the rise of bottom water within the reach of 
plant roots, by the large interspaces between their grains. Any 
remaining doubts as to the nature of such underlying materials 
at particular points can then quickly be solved by the use of a 
post-hole auger or by digging, as thorough inspection and the 
taking of samples for each foot of depth may be found desir- 
able. 
* University publications on alkaline soils and their treatment may be had by application 
to Agricultural Experimeut Station, Berkeley. 
