Tomato root distribution under furrow irrigation

Abstract

The root distribution of mature tomato plants in a sandy loam soil under furrow irrigation was studied by measuring the lengths of roots washed from soil samples. Nearly 76 per cent. of the roots measured were found in the top 40 cm. of soil, but appreciable amounts of roots were found in the deepest samples (90-100 cm.). There were more roots half-way between plants in the row than closer to the plant, which suggests that mature root systems overlap when plants are spaced 29 ft. apart in the row. Distribution was compared for plants which had received an application of superphosphate and those which had not. Added phosphorus greatly increased the total length of roots and slightly increased the median root depth without much change in the relative values for these two measures between different lateral positions. In addition, there was some evidence for a local concentration of roots around the band of superphosphate. The relevance of the findings to cultivation and fertilizer practices in tomato culture is briefly discussed.