To establish a labor-saving cattle stocking management method in temperate grass area, we investigated animal performance in continuous stocking on Kentucky bluegrass (Poa pratensis L.) and white clover (Trifolium repens L.) mixed sward in Hokkaido for 16 years. Holstein cattle (mean initial age, 6.9 months; body weight, 231 kg) were put out to pasture. To reduce the surplus herbage, stocking was initiated at a plant length of 5 cm, and the annual fertilization rate was decreased to 2-3, 3, and 4-7 kg/10a/year of N, P₂O₅, and K₂O, respectively, and the entire amounts were fertilized in late June after spring flash. The average stocking intensity at the start was set at 1,107 kgBW/ha, and the number of grazing animals was reduced so that the daily body weight gain was 0.8 kg/head/day or more during the grazing period. The number of the fixed stocking days and the body weight gain per hectare were positively correlated with the herbage mass, and the daily gain per head was positively correlated with the CP content of the grass. Body weight gain (560-1,000 kg/ha) and stocking capacity (448-592 CD) were obtained.

To clarify the changes in botanical composition and herbage production, and factors affecting them under labor-saving management, Holstein raising cattle were put out to pasture on Kentucky bluegrass (Poa pratensis L., KB) and white clover (Trifolium repens L., WC). mixed sward in Hokkaido for 16 years. To reduce surplus herbage, stocking was initiated at 5 cm plant length, and the entire amounts were fertilized in late June after spring flash. The annual mean value of the dry matter weight ratio of Agrostis alba L. coincided with the change in soil potassium content. By keeping the fertilizer component content in the soil within the standard range, the annual means of dry matter weight ratios of KB and WC were maintained in the ranges of 39-65% and 9-39%, respectively. The annual mean of daily dry matter production fluctuated in the range of 2.1-5.3 g DM/m² and increased with increasing total precipitation in May-October and the annual average dry matter ratio of WC. Based on our reports’ results, it was considered that KB-WC mixed sward in Hokkaido has a certain degree of herbage production under continuous stocking conditions under stable botanical composition for a long period.

Field experiments with sorgo-type sorghum (Sorghum bicolor Moench) ‘Tarzan’ were conducted for two years (2018-2019) to evaluate its productivity and adaptability in northern and eastern Hokkaido, which are colder throughout the year than other areas in Hokkaido. Considering changes of dry matter yields and dry matter ratios of sorghum ‘Tarzan’ in these areas, the optimal planting time was ascertained as the period from May to early June. Regional and annual variations of productivity were found among the field experiments, which suggested that differences in the effective cumulative temperature based on 14°C during June-August influenced ’Tarzan’ productivity. The effective cumulative temperatures based on 12°C, at which the dry matter ratio reaches 25% and 30%, were 652°C and 705°C, respectively, for ‘Tarzan’. Maps of the estimated harvest times based on these effective cumulative temperatures showed that the dry matter ratio could be 30% in the flat area of Kamikawa in northern Hokkaido and 25% in the central of Tokachi in eastern Hokkaido. Therefore, these areas might be suitable for cultivation.