北美南方的松树,人们完全可以期望通过施肥促进其生长。在干旱砂地上的湿地松,只有在氮肥和覆盖物结合使用的情况下才能增加生长量。为此,在苗木栽植后,把1.2米的带状塑料布放在树苗周围。覆盖物能有效地减少草本植物对水分和氮肥的竞争。树龄较大的湿地松林, Pine trees in North America, one can expect to promote their growth through fertilization. Pinus elliottii on arid lands can only grow if nitrogen and cover are used in combination. To this end, the seedlings planted, the 1.2-meter strip of plastic cloth placed around the saplings. Covering can effectively reduce the competition of herbs and water and nitrogen fertilizer. The older pine forest,