In The Prairie Farmer I notice the interesting note of "O." of Sheboygan Falls, Wis., on the apparent benefit resulting from sand and manure mulching of pear trees.
In the very near future I expect to see much of this kind of work done by commercial orchardists. Already we have many trees in Iowa mulched with sand.
I wish now to draw attention to the fact that on the rich black prairie soils west of Saratov—about five hundred miles southeast of Moscow—every tree in the profitable commercial orchards is mulched with pure river sand. The crown of the tree when planted is placed about six inches lower than usual with us in a sort of basin, about sixteen feet across. This basin is then filled in with sand so that in the center, where the tree stands, it is three or four inches higher than the general level of the soil. The spaces between these slight depressions filled with sand are seeded down to grass, which is not cut, but at time of fruit gathering is flattened by brushing to make a soft bed for the dropping fruit and for a winter mulch.
The close observer will not fail to notice good reasons for this treatment. (1.) The sand mulch maintains an even temperature and moisture of the surface roots and soil and prevents a rapid evaporation of the moisture coming up by capillary attraction from the sub soil.
(2.) The soil under the sand will not freeze as deeply as on exposed surfaces, and we were told that it would not freeze as deeply by two feet or more as under the tramped grass in the interspaces.
(3.) With the light colored sand about the trees, and grass between, the lower beds of air among the trees would not be as hot by several degrees as the exposed surface, even when the soil was light colored clay.
(4.) A bed of sand around the trunks of the trees will close in with the movement of the top by the summer and autumn winds, thus avoiding the serious damage often resulting from the swaying of the trunk making an opening in the soil for water to settle and freeze.
Still another use is made of this sand in very dry seasons, which as with us would often fail to carry the fruit to perfection. On the upper side of large commercial orchards, large cisterns are constructed which are filled by a small steam pump. When it is decided that watering is needed the sand is drawn out, making a sort of circus ring around the trees which is run full of water by putting on an extra length of V spouting for each tree. When one row is finished the conductors are passed over to next row as needed. To water an orchard of 1,200 trees—after the handy fixtures are once provided—seems but a small task. After the water settles away, the sand is returned to its place.
In the Province of Saratov we saw orchards with and without the sand, and with and without the watering. We did not need to ask if the systematic management paid. The great crops of smooth apples and pears, and the long lived and perfect trees on the mulched and watered orchards told the whole story of the needs of trees planted on black soil on an open plain subject to extreme variations as to moisture and temperature of air and soil.
J. L. Budd.
Iowa Agricultural College.