Re:ci.aiming Nitre Soie in Grand Vaeeey 
7 
Fig 4. A cover crop of hairy vetch in a Grand Valley orchard 
CLEAN CULTIVATION RESPONSIBLE FOR PRESENCE 
OF NITRE 
As indicated above, the presence of excessive nitre in so many 
of the orchards in Grand Valley, is in the main, due to the pre¬ 
vailing system of soil culture. It has been a universal custom in 
the Valley, up to within a few years ago, to practice clean culti¬ 
vation in the orchards, and this practice seems to have given the 
best results. The clean culture method is advisable only so long 
as the soil conditions remain favorable to tree growth and fruit 
production, and when these show signs of decline, corrective 
measures must be taken. The corrective remedy lies in the use of 
cover crops, alternating with clean culture. The use of cover 
crops is now more extensively practiced in the Grand Valley or¬ 
chards, and with its more extended use, we shall look for less 
nitre poisoning. 
DRAINAGE IMPORTANT 
In connection with the reclamation of nitre land, it should be 
borne in mind that drainage is of vital importance. If irrigating 
waters percolating thru the soil have a means of escaping readily, 
the nitre salts will be carried off by them, as they are very soluble. 
Lack of proper drainage makes evaporation the only source by 
which water is eliminated from the land, and this is sure to cause 
