Abstract
Effect of spring-sowing herbage species on the establishment of Zoysia japonica Steud. and forage production during establishment of Z. japonica pasture was investigated in the warm temperate region of Japan. Sods of Z. japonica planted and seeds of herbage species sowed in March 1995. The extent of establishment of Z. japonica was determined by visual observation of coverage and frequency of occurrence after clipping the herbage. Frequency and coverage of Z. japonica where herbage species were not sown (control treatment) increased rapidly in the first year,reaching 100% in May and July of the second year, respectively. On the other hand, frequency and coverage of Z. japonica where herbage species were sown (sown treatment) were relatively low in the first year and increased slowly in the second year. In the second year, the coverage of Z. japonica in September was significantly negatively correlated with the coverage of herbage species in June, July and August in sown treatments. Dry matter production of Z. japonica in the control treatment was 42g/m^2 in the first year when it did not produce any yield in the sown treatments, and 396 g/m^2 in the second year, when it was 4-57 times higher than the production in sown treatments. In sown treatments, 926-1,669 g/m^2 of forage was produced by sown herbage species in the first year and 555-1,004g/m^2 in the second year. It was therefore apparent that shading and competition for nutrient and water by sowing herbage species during the establishment of Z. japonica to increase forage production suppressed the growth of Z. japonica. Thus, establishment of Z. japonica was completed earier with little weed and the warm temperate condition where herbage species are not sown.
