To evaluate the capacity of the silk tree, Albizia julibrissin Durazz., a pioneer legume tree, to fertilize or shelter cool-season grasses, I investigated its effects on orchardgrass, Dactylis glomerata L. At three sites where isolated silk trees and D. glomerata grew together, I measured the height and yield of D. glomerata along belt transects, and compared the nutritional contents beneath and beyond the canopies. Plant height and dry matter yield decreased away from the stems of the trees. CP, DE, and OCC+Oa were higher beneath the canopy, and Ob was higher beyond the canopy in the second crop. TDN yield and CP yield were higher beneath the canopy in the first crop. The difference in yield performance between the two locations was larger in the first crop, but the difference in nutritional properties was larger in the second crop. These results suggest that the major environmental factors affecting the growth of D. glomerata are not uniform beneath the canopy of A. julibrissin, but become more favorable closer to the stems, and that A. julibrissin could fertilize and shelter D. glomerata in Japan’s hot summers.

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An one-operation seeding machine was developed, combining a vertical-axis type harrow and a pneumatic seeder for silage corn (Zea mays L.) planting in crop rotation with Italian ryegrass (Lolium multiflorum Lam.), and corn growth and work efficiency were compared between the one-operation seeding method and a conventional tillage and seeding method. The working hour of seeding by the one-operation seeding machine was 14min/10a (work speed was 0.6m/s), and it corresponded to 35% of the conventional method. And, in the one-operation method, the work efficiency was expected as 2ha per person in 6 hours. The average corn yield from 2008 to 2012 was 1,956kg/10a and 1,942kg/10a in the conventional method and the one-operation method, respectively, and there was no significant difference between the two methods. Thus, it was concluded that the one-operation method was labor saving technique, and that its corn yield would be at the same level as that in the conventional method. However, it was also clarified that, in the one-operation method, aftermath of Italian ryegrass in the previous cropping affected the corn yield, and the one-operation seeding should be implemented before Italian ryegrass regrow until 36cm.

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Five festulolium cultivars (Nakei 1, Nakei 2, Tohoku 1, Tohoku 4, and Barfest) were sown on September 30, 2010, and grown for three years. The first cutting was performed on May 31, 2013; second cutting, July 17, 2013; third cutting, September 2, 2013; and fourth cutting, October 21, 2013. We investigated the total polyphenol content, anti-oxidative activity, and dry matter yield. Significant differences in total polyphenol content and anti-oxidative activity were not detected between cultivars in the first, second, and third crops, but were detected in the fourth crop. Cultivars with higher resistance to heat stress during summer in Japan (Nakei 1 and Nakei 2) did not show a trend for increasing total polyphenol content and anti-oxidative activity, as compared to the other cultivars. The results suggest that the total polyphenol content and anti-oxidative activity of festulolium are not associated with resistance to heat stress during summer in Japan.

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