Abstract:

In recent years, afforestation shifted from land suitable for afforestation to the harsh sites asks for a higher quality of seedlings to overcome the environment stress. It is essential to review the late decade abroad advances in intensive container seedlings culture for applying the techniques to forest restoration in stressful sites in China. This paper summarized current techniques such as exponential fertilization, fall fertilization, subirrigation, short-day treatments and hot-planting, root pruning, container size, as well as cold storage and thawing. Exponential fertilization has been approved to be more effective because fertilizer is raised progressively to match exponential growth and nutrient demand. Fall fertilization, applied in autumn, can avoid growth dilution of nutrients, which has been successfully applied in many tree species. Plants with subirrigation grow at least as well as their cohorts with overhead irrigation, besides, subirrigation needs less water inputs, and less nitrogen leaching. Field performance of a seedling can be improved by stopping shoot growth in summer with the seedling exposed to short-day treatments, by which the root system growth can be enhanced. Freezer storage of conifer seedlings has become a standard operating procedure for many commercial nurseries, because freezing converts all the free water to ice in the storage container, and thus the development of pathogenic fungi is retarded. This paper prospected future study trends on techniques to promote seedling quality.

Key words: exponential fertilization, fall fertilization, subirrigation, short-day, freeze storage, seedling quality