随着经济的发展，２１世纪的人类食物结构正在向保健营养型转变，对坚果的需求越来越大，如美国薄壳黑核桃、我国的板栗、银杏等成了国际市场上的紧俏货，药用、化纤和美容所需价格昂贵的辛荑、杜仲市场销售紧缺，所以发展“铁杆庄稼”前景十分广阔。 干果适应性强，栽植容易， With the development of economy, human food structure in the 21st century is changing to health and nutrition, and the demand for nuts is getting larger. For example, American black shell walnut, Chinese chestnut and ginkgo have become the tight goods on the international market, Medicinal, chemical fiber and beauty needed expensive Xin, Eucommia market sales in short supply, so the development of “hardcore crops” has a very broad prospect. Adaptability of dried fruit, planting easy,