A Study on Influencing Factors for Vertical Growth of Tree's Root

To examine the methods of quick cultivation technique of tree long root-seedling,this study took Pinus sylvestnis var. mongolica Litv. and Hippophae rhamnoides Linn. as the study object,and study the influence of soil substrate ratio,soil moisture,irrigation method and plant growth regulator( N-1-naphthylphthalamic acid) on vertical growth of tree' s root,the result was that: soil substrate ratio had significant effect on vertical growth of Pinus sylvestnis var. mongolica Litv. and Hippophae rhamnoides Linn. ' s root,compared with the control( pure-dune sand,the soil density was 1. 3 g·m- 3),under the treatment of dune sand∶ peat soil( volume ratio) = 1∶2( the soil density was 0. 7 g·m- 3),the vertical length of Pinus sylvestnis var. mongolica Litv. and Hippophae rhamnoides Linn. 's root were respectively increased by 36. 6% and 27. 1%. Soil moisture also had significant effect on vertical growth of their root,compared with the treatment of water stress,enough water could improve the vertical growth of their root by 22.0% and 20. 8%. Irrigation method only had significant effect on vertical growth of Pinus sylvestnis var. mongolica Litv. 's root,compared with irrigation from upper part,water absorption from lower part could improve the vertical growth of Pinus sylvestnis var. mongolica Litv. 's root by 24. 6%. Plant growth regulator only had significant effect on vertical growth of Hippophae rhamnoides Linn. 's root,compared with no NPA application,NPA application could improve the vertical growth of Hippophae rhamnoides Linn. ' s root by 30. 6%.