Purpose

Significant leaching losses of nitrogen (N) and phosphorus (P) from soil occurred during the summer fallow period of intensive plastic-shed vegetable production systems, which could be resolved by catch crops.

Materials and methods

We firstly estimated the economic profits and then evaluated the efficiencies of six catch leafy vegetables on reducing N and P leaching losses. Meanwhile, responses of soil nutrient contents and the yield as well as the quality of subsequent lettuce were observed under plot-scale experiment.

Results and discussion

The six leafy vegetables as catch crops can bring approximately 23, 000–43, 000 yuan RMB hm^–2 extra economic profits to farmers. There were five catch treatments that reduced the NO₃^–-N leaching losses from 22.7 kg hm^–2 under the control treatment to 4.6–15.8 kg hm^–2. The total P leaching losses were lower under all six catch crop treatments (with 10.5–22.3 kg hm^–2) than that under the control treatment (with 39.2 kg hm^–2). The mitigation efficiency of catch crops on N and P leaching losses was dependent on the vegetable variety. Overall, vegetable crops did not exhaust soil available N but increased soil available P by 42.1% and organic matter content by 16.8%. The catch crop-based vegetable plantation did not influence yield and N and P uptake capacities of subsequent lettuce. As such, the qualities of lettuce (including the soluble protein, sugar, vitamin, and nitrate contents) were also not influenced following the plantation of catch crops.

Conclusions

Leafy vegetable as catch crop during the fallow season increased farmer’s income while reducing N and P leaching losses. Moreover, there were no negative effects on subsequent vegetable production and qualities. We can also attempt to reduce the input of N and P chemical fertilizers to subsequent vegetable, as increased available P and organic matter were found in the catch crop treatments.

中文翻译：

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叶菜类蔬菜作为农作物的好处，可减轻集约化塑料大棚生产系统中的氮和磷淋失

目的

在集约化塑料棚蔬菜生产系统的夏季休耕期，土壤中氮（N）和磷（P）的淋失显着增加，这可以通过农作物来解决。

材料和方法

我们首先估算了经济利润，然后评估了六种多叶蔬菜在减少氮和磷淋失方面的效率。同时，在样地规模试验下，观察了土壤养分含量，产量以及后续生菜质量的响应。

结果与讨论

六种多叶蔬菜作为农作物可以给农民带来大约23，000–43，000元人民币hm ^–2的额外经济收益。有五种捕捞处理将NO ₃ ^-- N淋失损失从对照处理下的22.7 kg hm ^-2降低到4.6-15.8 kg hm ^-2。在所有六种作物的处理下（10.5-22.3 kg hm ^-2），总磷淋失量均低于对照处理下的（39.2 kg hm ^-2））。捕获作物对氮和磷淋失的缓解效率取决于蔬菜品种。总体而言，蔬菜作物没有耗尽土壤中的有效氮，但使土壤中的有效磷增加了42.1％，有机质含量增加了16.8％。以农作物为基础的蔬菜种植园不影响随后生菜的产量以及氮和磷的吸收能力。因此，种植农作物后，生菜的品质（包括可溶性蛋白质，糖，维生素和硝酸盐含量）也没有受到影响。

结论

休耕季节以叶类蔬菜作为农作物，增加了农民的收入，同时减少了氮和磷的淋失。而且，对随后的蔬菜生产和品质没有负面影响。我们还可以尝试减少后续蔬菜中氮和磷的化肥投入，因为在农作物的处理中发现了可利用的磷和有机质增加。