The Effect of Farmcompost Application to the Paddy Field on the Formation of Superficial Roots of Rice

Abstract

The supericial roots of rice emerge after the spikelet differentiation stage and concentrate near the soil surface, forming a net with many branched roots. A long-time application of farmcompost to the paddy field in the Agricultural Experiment Stations of Aomori and Fukushima Prefectures for forty-five years and fifty-five years, respectively, was proved to accelerate the development of superficial roots of rice. The superficial roots of rice in these farmcompost-applied fields had the following characteristics over the control. (1) Most of the primary roots distributed near the soil surface (up to 3 cm depth). (2) The length of the thick secondary roots was longer than those of control. (3) The density of the formation of the secondary roots on the primary roots and that of the tertiary roots on the thick secondary roots were higher than those of the control. (4) Additional lateral root branches, for instance, the fifth lateral roots, were observed. (5) "Lion-tail-like roots" remarkably decreased in number. The data obtained through this investigation are not sufficient to clarify how the superficial roots with such characteristics were developed. Further studies are needed for this clarification