棉花苗期茎叶生长慢,茎秆幼嫩,叶面积小,对外界不良环境的抵抗力弱,易感病,其生长中心是根,地下部分根系生长快,其速度远超过地上部分。苗期管理主要以保持土壤水分,提高土壤温度,促进根系发育,使其达到争早苗、留匀苗、保全苗,促壮苗早发,努力实现早、全、齐、匀、壮五苗。因? Cotton seedling stem and leaf growth is slow, young stems, leaf area is small, weak resistance to the external environment, susceptible to disease, the growth center is the root, underground part of the root system grows faster, its speed is far more than the aerial part. Seedling management mainly in order to maintain soil moisture, soil temperature and promote root development, so that it reached the fight early seedlings, leaving uniform seedlings, protect seedlings, and promote strong seedling early onset, and strive to achieve early, full, homogeneous, strong five seedlings. because?