Department of Applied Biology, Kyoto Institute of Technology, Ukyo, Kyoto, 616-8354, Japan.
Institute of Tropical Medicine, Nagasaki University, Sakamoto, Nagasaki, Nagasaki, 852-8523, Japan.
Sci Rep. 2022 Aug 2;12(1):13283. doi: 10.1038/s41598-022-15568-x.
The use of plastic film imposes various environmental risks in agroecosystems. The replacement of plastics with organic materials for mulching has been suggested to enhance the sustainability of agroecosystems. However, whether woodchip mulch can be used for annual crops needs to be verified. We examined the effects of mulberry woodchip mulches on tomato-fruit yields over two successive years. Mulberry is the unique food plant of silkworms, and it will be better if its pruned shoots can be recycled rather than incinerated as waste. Setting three treatments, including woodchip mulch, weed-free and weedy (i.e., unweeded) treatments, we compared the amounts of fresh-marketable and unmarketable tomato fruits. The yields of fresh-marketable tomato fruits in the woodchip mulch treatment were significantly 16-57% higher than those in the weed-free treatment and comparable to those in the weedy treatment. The yields of unmarketable dehiscent tomato fruits in the weed-free treatment were significantly 46-86% higher than those of the other two treatments. The woodchip mulches extensively suppressed the weed density, while the grown weeds became large, preventing strong sunlight exposure and dehiscence of tomato fruits. Current results suggest that woodchips could be a possible alternative to plastics, facilitating climate change mitigation with agroforestry practices.
塑料薄膜在农业生态系统中造成了各种环境风险。为了提高农业生态系统的可持续性，有人建议用有机材料代替塑料进行覆盖。然而，木片覆盖物是否可用于一年生作物仍需验证。我们连续两年考察了桑木片覆盖物对番茄果实产量的影响。桑树是蚕的特有食物植物，如果其修剪后的枝条可以回收利用而不是作为废物焚烧，那就更好了。设置了木片覆盖物、无草和杂草（即未除草）三种处理，我们比较了新鲜可销售和不可销售的番茄果实的数量。木片覆盖物处理的新鲜可销售番茄果实产量比无草处理分别高出 16-57%，与杂草处理相当。无草处理的不可销售开裂番茄果实的产量比其他两种处理分别高出 46-86%。木片覆盖物广泛抑制了杂草密度，而生长的杂草变得很大，防止了强烈的阳光照射和番茄果实的开裂。目前的结果表明，木片可以作为塑料的一种替代物，通过农林复合经营实践促进气候变化缓解。
