[Background] Strengthening the property of soil moisture conservation is one of important measures for raising afforestation quality in the arid-semiarid areas. The west of Heilongjiang Province is a semiarid area, thus investigating soil moisture conservation technique is urgently needed for increase water-saving, drought-resistance and planting quality in this area. Based on the result of former research, surface covering is an effective measurement for soil moisture conservation in arid-semiarid areas. Our research aimed to evaluate the major surface covering methods used in this area based on the cost and ffectiveness. [Methods] Using 3 measures of surface covering of plastic film, straw and sand, we studied their influences on soil moisture conservation in the semiarid area of Heilongjiang Province. Surface covering blanketed about 1-2 m2 area around rootstock of new plantation, with new plantation that did not adopt any kind of surface covering as contrast. Soil moisture contents at the depth of 20 -30 cm near root zone, plant height growth and afforestation survival rate were periodically monitored. [Results] Based on the data collected in April, June, August and October from 2008 to 2009, we found that surface covering significantly increased the soil moisture content. The improvement in soil moisture content was the most obvious in spring season in which the precipitation was generally low. Comparing to the contrast, soil moisture contents increased by 58.93%, 32.91%, and 24.97% with plastic film, straw, and sand, respectively. We found that surface covering increased the survival rate of afforestation and the growth of plant height. The afforestation survival rate by 3 covering methods of plastic film, straw, and sand raised 13.9, 11.7, and 10.6 percentage points, respectively, in comparison to the contrast. The average annual increment in height of Pinus sylvestris var. mongolica in 6 years from 2008 to 2013 was 23.35%, 5.08%, and 9.64% by plastic film, straw and sand respectively. In comparison to the contrast, the increment of afforestation cost was 4.4% for plastic film covering, 9.3% for straw covering, and 9.2% for sand covering. By comprehensive comparing the cost and survival rate of afforestation with the contrast, the suface covering was a cost-efficient technique. [Conclusions] From comprehensive evaluation of indexes — survival rate, increment in height in the initial 6 years, initial afforestation cost, conclusion is: plastic film covering > sand covering > straw covering > contrast.However, plastic film covering is prone to damage by wind as time prolonging, thus the durability of plastic film covering is not as favorable as sand covering. Beside that, plastic film covering may cause the environmental problem, i. e. , white pollution. While these shortcomings in plastic film covering are solved with the progress of science and technology, for example, using biodegradable plastic film, then the surface covering with plastic film covering could be extensively utilized as an effective approach for increasing afforestation quality in arid-semiarid areas.
王力刚, 李峰, 王炜烨, 刘文环. 黑龙江西部地表覆盖保墒的抗旱造林技术[J]. 中国水土保持科学, 2016, 14(2): 147-154.
Wang Ligang, Li Feng, Wang Weiye, Liu Wenhuan. Drought-resistant afforestation techniques for soil moisture conservation by using surface covering in Western Heilongjiang Province. SSWC, 2016, 14(2): 147-154.