Abstract
1. Surface runoff and soil erosion, soil temperature, soil moisture and the growth of peach seedlings under five systems of culture, were compared in the clayey orchard, of which slope 28 per cent, during May to October in 1951. The results were as follows;
2. On runoff and erosion control, the effects of the cultivation under straw mulch, sod culture and winter cover crops (grass mulch during peach tree growing season), were distinguished on the same rate, but summer cover crops was less. Runoff soil did not always follow runoff water and it seemed that the proportion of soil to water varied by system of culture, property of rain and soil, seasonal transfiguration of treat meats and others. The class of runoff soil was not so different as to distinguish the difference of soil managements, but the runoff soil was remarkably less in the percentage of pebble than that of the surface soil of test field.
3. The difference of the shoot linear growth of peach seedlings between systems of culture, appeared evidently during the end of July to the beginning of September and the total length wes classified as following order ; straw mulch> winter cover crops> clean culture> summer cover crops> sod culture. The same effect was noted on the total top and root fresh weight. In all systems of culture, the root penetrated deeper than 60cm, and the concentration of root was greatest at 5 to 10cm in depth, but the greatest concentration of fine root was different in depth between systems.
4. The influence of systems of culture on the soil temperature was distinguished still at 30cm in depth. Under straw mulch, sod culture and winter cover crops, the temperature was too low to growth of peach tree during May to June. In midsummer, it was too high under clean culture and winter cover crops. On and after September, the soil temperature fell early under straw mulch, summer cover crops and sod culture. The influence of soil temperature for top and root growth of peach tree was not evident, but for the distribution of roots in upper 10cm of soil, especially of fine root, was fairly distinct.
5. The influence of soil managements on the soil moisture was visible at 30cm in depth. Under straw mulch, the soil moisture was optimum always at all depth and winter cover crops was next suitable. Lack of soil moisture was limited within 20cm depth of surface soil under clean culture, but it was considerably great still 20-30cm in depth under sod culture and summer cover crops. The influence of soil moisture for growth of peach seedlings seemed fairly distingiushed.
