Abstract:

The paper summarized the research results of farmland shelterbelt on negative effect(output reduction)and its control measures in China in recent years, especially in plain agricultural areas so as to explore the degree of output reduction and its influencing factors, and to find an effective way to reduce the negative effects. The results were as follows: ① Because of the differences in geographical location, natural conditions and tree species biology, the negative effect distance of shelterbelts was different. But in plain agricultural areas, the negative effect distance of shelterbelts in China was 0~[0.4H,2.0H] (H was the average height of shelterbelt. The degree of threatened land was 0.4H, 0.5H, 0.6H,…, 2.0H, etc. The same below.), and the negative effect distance of the most shelterbelts was 0~[0.8H,1.5H]. ② The influence of different direction shelterbelts on the negative effect was different, and if the shelterbelt was north-south direction, the range of the western negative effect was larger that was 0.4H-1.5H; while for east-west direction shelterbelt,the northern range of negative effect was larger that was 0.4H-2.0H. The range and degree of the northern area of the negative effect was the largest, and the southern range of the negative effect was the smallest. ③ Although the east-west direction shelterbelt can reduce the shade area more than the north-south direction shelterbelt, it may not increase the yield. ④ Increasing the distance between the shelterbelt and the farmland, planting narrow canopy tree species, strengthening the pruning and selecting the suitable crops were the most effective methods to reduce the negative effect of crown; the most effective method of reducing negative effect of the root was to cut the root and stick the film.

Key words: farmland shelterbelt, negative effect (output reduction), control measure