Studies on the Culture of Italian Ryegrass sown in Mixtures with Legumes as Winter Crop on Paddy Fields : Report II. Yield of Italian Ryegrass sown in Mixtures with Common Vetch

Abstract

Yields of Italian ryegrass sown in mixtures with common vetch were tested in 1963 and 1964 under the plan shown in Tables 1 and 2. (1) In case where cutting was not practiced within the seeding year. In the case of test carried in 1963, i. e., when sown late under heavy manuring condition, any great difference was not found, as seen in Table 3, between the plots under different treatments. Under light→heavy manuring conditions, the yield of Italian ryegrass sown in mixtures at the first cutting was higher than that of Italian ryegrass sown alone, while the yield of Italian ryegrass sown in mixtures was less at the second cutting than that sown alone because of no regrowth of common vetch and on account of poor regrowth of Italian ryegrass due to the competition with common vetch. At the subsequent cuttings, any difference in yield of Italian ryegrass was not found. As a result, no great difference was found in total yield between Italian ryegrass sown alone and that sown in mixtures. In comparison of the yield of Italian ryegrass sown alone under heavy manuring condition with that of Italian ryegrass sown in mixtures under light→heavy manuring conditions, the total yield of Italian ryegrass sown in mixtures was less because of less yields at the first and second cuttings. The yield of Italian ryegrass at the first cutting in the case of test carried in 1964 is as seen in Fig. 1, namely, in the cases of early-cuttings (i. e., under the treatments A and B), any significant difference in yield is not found between Italian ryegrass sown in mixtures with common vetch (at the rate of 200 seeds per m²) under light→heavy manuring conditions and Italian ryegrass sown alone under heavy manuring condition, while in the case of late-cuttings (i. e., under the treatments C and D), the yield of Italian ryegrass sown alone under heavy manuring condition is higher. In the case of yield under the treatments A and B, thanks to the great effect of the first cutting, total yield (as shown in Fig. 3) of the plot of Italian ryegrass sown in mixtures at the rate of 200 seeds per m² can approach to that of Italian ryegrass sown alone under heavy manuring condition, while in the case of yield under the treatments C and D, the yield of Italian ryegrass sown in mixtures becomes less than that of Italian ryegrass sown alone under heavy manuring condition. The reason for that Italian ryegrass sown in mixtures under light→heavy manuring conditions in 1963 was less than that of Italian ryegrass sown alone under heavy manuring condition (as seen in Table 3) lies in the fact that the first butting was practiced in the periods in 1964 corresponding to the treatments C and D. Consequently, when Italian ryegrass is sown in mixtures With common vetch for the purpose of saving the fertilizer to be applied before seeding and intended to gain the yield similar to that of Italian ryegrass sown alone under heavy manuring condition, it is necessary to practice the first cutting somewhat earlier. In doing so, the yield in each cutting can be ironed out and the crude protein yield will become higher as seen in Fig. 4. (2) In case where cutting is practiced within the seeding year. As seen in Table 3, through the first cutting practice within the seeding year. Italian ryegrass sown in mixtures under light→heavy manuring conditions gains the yield similar to that of Italian ryegrass sown alone under heavy manuring condition. But in the case of the first cutting practiced in next spring the yield of Italian ryegrass sown in mixtures is less and lower in total yield than the yield of Italian ryegrass sown alone under heavy manuring condition, because light→heavy fertilizer plots were still kept under light manuring condition until the first cutting in spring. [the rest omitted]