干旱区生态环境知识资源中心

The most important benefit of shelterbelts is protecting the adjacent soil and crops from injury of the erosive winds. However, farmers are often averse to implement this conservation measure. The main reason is that shelterbelts occupy valuable land of production and compete for moisture and nutrients with crops. Scientific research in other parts of temperate regions shows that improved yields adjacent to shelterbelts can help to compensate the lost of production. It was important to assess the effects on yields under the desertification regions of Shandong. In the present study, a 7.8-ha wheat field with 13-year-old shelterbelts of Populus euramericana was monitored. Wind element and winter wheat yield were measured at various distances from the leeward side of the shelterbelt. A comparison was also made with unsheltered area. The investigations indicate that the tree belt was able to reduce the wind speed by 20 to 25%. There was a yield increase in the 1H to 15H area with a maximum increase of 82% at 5H. In this case there was effective wind protection for the crop and the shelterbelt did not compete with the crop except at 8 +/- 1 m nearby the shelterbelt. The weighted average yield in the sheltered zone (0H to 17H) was 30% more than the unsheltered field yield. Meanwhile, winter wheat thousand grain weights were 12 g higher compared to unsheltered fields. It indicates that shelterbelts establishment should be adopted and integrated to a whole farming system in desertification regions of Shandong.