Studies on physical properties of soils in relation to fruit tree growth

Abstract

1. Young peach seedlings were planted in four tree rows in sandy loam soil orchard. Alternate two rows of trees were mulched with 3kg of straw per tree on July 4 and remaining two rows were clean cultured. Thereafter soil moisture in 20, 60 and 120cm depth and total length of top growth were measured about every 10 days and top and root fresh weight and root distribution were investigated. 2. The difference of soil moisture, below the 20 cm depth, by the soil managements was less than that of soil moisture by location. Since be-ginning of August, a month after mulching, total top growth in mulched plots was supeAor to that of clean cultured and on September total length of top growth in every tree row mulched was longer than that of clean cultured. 3. Top and root fresh weight were heavier in mulched plots than clean cultured. Root distribut ion of mulched plots was especially greater in depth of 0_??_10cm. Fine root less than 1mm in diameter distributed chiefly in 0_??_10cm depth in mulched plots and 10_??_20cm in clean cultured. The root distribution between the 20 and 60cm depth was not so different as to distinguish the difference of surface soil managements. But the roots of mulched trees penetrated deeply and the fresh weight of roots below 60cm depth was more than that of clean cultured. The present results seems to point to the good penetration of roots by the vigorous tree growth notwithstanding of abundant shallow root distribution in surface soil. The difference of soil moisture about 10cm deep was not measured but the effects of mulching on the soil moisture, under present soil condition, seemed to be limited within only 20cm depth of surface soil.