CAJ | 학술논문

为了综合分析深沟造林条件下秸秆覆盖对土壤养分和盐分的影响，该研究于2008－2012年在新疆塔城盆地老风口生态区新植林地进行了4 a定位试验，设置了3个处理，即深沟70 cm秸秆覆盖、深沟70 cm不覆盖和常规（不深沟不覆盖），分析了这3种处理在2008－2012年间的土壤养分和盐分的变化特征。结果表明：4 a后，深沟秸秆覆盖条件下土壤容重降低9.7%～24.9%，孔隙度提高11.2%～20.2%，饱和持水率增加13.0%～24.6%，土壤有机质质量分数增加24.48%。土壤容重、孔隙度、饱和持水率、养分含量改善情况均为：深沟秸秆覆盖>深沟秸秆不覆盖>常规。深沟秸秆覆盖条件下土壤表层（0～20 cm）盐分降低35.7%，底层（≥40～70 cm）土壤盐分降低2.9%，而深沟不覆盖盐分降低不显著。该研究表明，深沟秸秆覆盖改善了土壤结构、提高土壤养分、抑制蒸发和盐分表聚，为树木的正常生长提供了有利条件。
위료종합분석심구조림조건하갈간복개대토양양분화염분적영향，해연구우2008－2012년재신강탑성분지로풍구생태구신식임지진행료4 a정위시험，설치료3개처리，즉심구70 cm갈간복개、심구70 cm불복개화상규（불심구불복개），분석료저3충처리재2008－2012년간적토양양분화염분적변화특정。결과표명：4 a후，심구갈간복개조건하토양용중강저9.7%～24.9%，공극도제고11.2%～20.2%，포화지수솔증가13.0%～24.6%，토양유궤질질량분수증가24.48%。토양용중、공극도、포화지수솔、양분함량개선정황균위：심구갈간복개>심구갈간불복개>상규。심구갈간복개조건하토양표층（0～20 cm）염분강저35.7%，저층（≥40～70 cm）토양염분강저2.9%，이심구불복개염분강저불현저。해연구표명，심구갈간복개개선료토양결구、제고토양양분、억제증발화염분표취，위수목적정상생장제공료유리조건。
In order to provide theoretical basis for the sustainable utilization of desert sand gravel soil, we studied the effects of straw mulching on the nutrients and salt in the soil under the condition of deep trench planting and assessed the capabilities of straw mulching such as soil nutrients accumulation, inhibiting soil evaporation and soil salt accumulation in surface soils. Field experiments were conducted in Laofengkou ecological zone located in the Tacheng basin of Xinjiang. The total experimental area was 10 000 hm2, where grooves were excavated parallelly by using mini excavators according to contour lines. The spacing between grooves was 3.0 m and the length, width and depth of each groove were 50 m, 50 cm and 70 cm respectively. Wheat straw with a thickness of about 20 cm was mulched to the grooves and the quantity for each groove was 5 m3. And the length of wheat straw was in accord with the crush degree of the wheat harvester. The biennial plant Popolus Russkii was selected as the experimental plants, and the planting spacing was 2.0 m. Three treatments were designed as follows: 1) straw coverage for 70 cm groove; 2) no straw for 70 cm groove; and 3) conventional planting without straw. Soil samples were collected in July, 2008 (before experiment) and in September, 2012 in 3 depths of soil layers including 0-20, >20-40 and >40-70 cm. Nine sampling points were chosen randomly as replications for each treatment, and finally 108 soil samples were collected. Then we used the cutting ring weighing method, the contamination of water saturation method and conventional methods, such as capacity of potassium dichromate method to analyze characteristics of soil nutrient and salt. The results of the study were as follows: the soil bulk density under the straw coverage for 70 cm groove treatment decreased by 9.7%-24.9% compared with the conventional planting treatment, whereas the soil porosity and the soil saturated water capacity increased by 11.2%-20.2% and 13.0%-24.6%, respectively. Soil organic matter increased 24.48% under straw mulching, and nitrogen also increased significantly. The soil bulk density was in such order: straw mulching for 70 cm groove > no coverage for 70 cm groove > conventional planting without straw. The soil porosity, soil saturated water capacity and soil organic matter were in the same order. As the age of the straw mulching in groove increased, straw coverage had obvious effects of inhibiting surface accumulation of soluble salt, and the salt rejection and pH value and total salt content in the soil of forest belts showed a decreasing trend. The salt content of the soil with straw mulching in deep groove decreased by 35.7% in surface layer and 2.9% in basement soil, but the salt content of the soil with no coverage in 70 cm groove decreased indistinctively. After afforestation for 4 years, the growth amount of trees in the straw coverage in 70 cm groove treatment was 1.61 times that in the treatment without straw coverage in 70 cm groove and 1.76 times that of the conventional treatment without straw mulch. In summary, straw mulching in groove planting can optimize the soil structure, improve the soil nutrient and inhibit soil water evaporation, and provide favorable conditions for the growth of trees.