スギ苗の生長と栄養に関する研究 : とくに秋伸びと関連して

In Japan, Cryptomeria japonica stands occupy neraly a half of manmade forests in area. In the nursery practices of cryptomeria seedlings, one of the important problem is the prevention of an unusually delayed height growth continued until late fall "the later growth in fall", by which the abilities of seedling to endure drought, winter-killing and frost injury are reduced. A decreased growth during a spell of dry weather in summer followed by an increased uptake of nitrogen in warm and humid fall had been given empirically as a cause of the later growth in fall. But there was no sufficient study of it. This paper consisted of two chapters. The experiments in Chapter 1 dealt with the effect of drying of soil on the growth and nutrient uptake of 1-year-old transplanted cryptomeria seedlings to make clear the cause of the later growth in fall. Refering to the relations in Chapter 1, the studies in Capter 2 dealt with the nutrition conditions especially in relation to nitrogen fertilization as a base of nursery practice for growing up stout seedlings