滨海泥质盐碱地衬膜造林技术

盐碱地造林是当今世界上许多国家面临的巨大难题,中国的滨海泥质盐碱地就是其中之一,盐分含量高至不适宜苗木生长的程度。研究目的在于检验衬膜在滨海泥质盐碱地造林中的成效。于2007—2009年,对使用衬膜的新造林模式和全面客土、穴状客土两种传统造林模式栽植穴内外土壤电导率值、含水量及苗木生长情况进行测定和分析。与传统造林模式相比,新造林模式在衬膜的作用下,其穴内客土土壤水分含量有明显提高,盐分含量也明显较低;2009年苗木的成活率、苗高和冠幅较全面客土传统造林模式同比高出150.00%,7.00%和12.00%,较穴状客土传统造林模式同比高出838.00%,12.00%和22.00%;选用的四种苗木中,香花槐效果最好,最适宜滨海泥质盐碱地这种新的造林体系,红叶杨不适宜滨海泥质盐碱地。结果表明,使用衬膜在滨海泥质盐碱地造林体系中效果明显,且成本低廉,宜于推广。

Research of padded film for afforestation in coastal argillaceous saline-alkali land

Afforestation in saline-alkali land is a challenge faced by many countries. Coastal argillaceous saline-alkali land has such a high salt content that seedlings cannot be established there. The purpose of this paper is to study the use of a padded film around the roots of tree seedlings to protect the roots of the seedlings from salt infiltration. From 2007 to 2009, we compared and analyzed three techniques, two conventional afforestation models including 1) a comprehensive new soil conventional afforestation model and 2) a new soil in hole conventional afforestation model, and 3) a new afforestation model, which used the padded film. We measured the survival rate and growth of tree seedlings, as well as the soil moisture and conductivity (salt) inside the planting hole. There was an inverse relationship between water and salt content. With the arrival of rainfall, soil conductivity decreased and soil moisture rose. In August, with the reduction in rainfall, soil conductivity gradually rose and soil moisture content declined. When compared with the conventional afforestation models, the use of the new method which used the padded film conserved soil moisture and increased soil conductivity inside the film lined planting hole. Seedling survival rates, height and canopy area using the new afforestation model increased by an average of 150.00%, 7.00% and 12.00%, respectively when compared with the comprehensive new soil conventional afforestation model. By using new soil in the planting hole, rather than just using the local soil and the conventional planting model, those figures increased even more dramatically to 838.00%, 12.00% and 22.00%. Using new soil is less cost effective than the traditional model of afforestation and the cost is also much higher than the new afforestation model. Use of new soil should not be promoted. However, the cost of using the film is only 0.58 yuan. Compared with the conventional planting model, the new afforestation model is low in cost but provides very effective results. The new model of forest planting cost 12.29 yuan per plant, and the cost effectiveness with this new model of afforestation has been significantly better than other two traditional planting models. By using the new afforestation model, the survival rate, the average height, and canopy cover of seedlings of each species were, respectively: Fraxinus chinensis Roxb., 65.63%, 2.04 m, 0.93 m2; Populus deltoides W. Bart. ex Marshall cv. Zhonghua hongye, 34.38%, 1.97 m, 0.84 m2; R. pseudoacacia, 53.13%, 2.11 m, 1.02 m2; and Robinia pseudoacacia L. cv. idaho, 81.00%, 2.17 m, and 0.94 m2. Based on these results for these four species, R. pseudoacacia cv. idaho was the most suitable and P. deltoides cv. Zhonghua hongye was unsuitable for use with this tree seedling technique in coastal argillaceous saline-alkali lands. These results show the padded film effectively prevented the infiltration of salt around seedling trees and reduced evaporation. Padded film can increase the survival rate of seedlings and provides a suitable environment for seedlings in the coastal argillaceous saline-alkali lands. The results provide a theoretical basis for promotion of this effective, simple, and low-cost afforestation and land reclamation technique in saline-alkali lands.