Sun Yuan, Chen Shaoqing, Feng Puyu, Chen Qing, Hu Kelin
College of Land Science and Technology, China Agricultural University, Key Laboratory of Arable Land Conservation (North China), Ministry of Agriculture and Rural Affairs, Beijing 100193, China.
Agricultural Information Institute of Chinese Academy of Agricultural Science, Beijing 100081, China.
Plants (Basel). 2024 Aug 3;13(15):2150. doi: 10.3390/plants13152150.
Nitrate leaching, greenhouse gas emissions, and water loss are caused by conventional water and fertilizer management in vegetable fields. The Expert-N system is a useful tool for recommending the optimal nitrogen (N) fertilizer for vegetable cultivation. To clarify the fates of water and N in vegetable fields, an open-field vegetable cultivation experiment was conducted in Dongbeiwang, Beijing. This experiment tested two irrigation treatments (W1: conventional and W2: optimal) and three fertilizer treatments (N1: conventional, N2: optimal N rate by Expert-N system, and N3: 80% optimal N rate) on cauliflower ( L.), amaranth ( L.), and spinach ( L.). The EU-Rotate_N model was used to simulate the fates of water and N in the soil. The results indicated that the yields of amaranth and spinach showed no significant differences among all the treatments in 2000 and 2001. However, cauliflower yield under the W1N2 and W1N3 treatments obviously reduced in 2001. Compared with the W1 treatment, W2 reduced irrigation amount by 27.9-29.8%, water drainage by over 76%, increased water use efficiency by 5-17%, and irrigation water use efficiency by 29-45%. Nitrate leaching was one of the main pathways in this study, accounting for 8.4% of the total N input; compared to N1, the input of fertilizer N under the N2 and N3 treatments decreased by over 66.5%, consequently reducing gaseous N by 48-72% and increasing nitrogen use efficiency (NUE) by 17-37%. Additionally, compared with the W1 treatments, gaseous N loss under the W2 treatments was reduced by 18-26% and annual average NUEs increased by 22-29%. The highest annual average NUEs were under W2N3 (169.6 kg kg) in 2000 and W2N2 (188.0 kg kg) in 2001, respectively. We found that optimizing fertilizer management allowed subsequent crops to utilize residual N in the soil. Therefore, we suggest that the W2N3 management should be recommended to farmers to reduce water and N loss in vegetable production systems.
菜地传统的水肥管理会导致硝酸盐淋失、温室气体排放和水分流失。Expert - N系统是一种用于推荐蔬菜种植最佳氮肥用量的有用工具。为了阐明菜地水分和氮素的去向，在北京东北旺进行了一项露地蔬菜种植试验。该试验对花椰菜（ ）、苋菜（ ）和菠菜（ ）测试了两种灌溉处理（W1：传统灌溉和W2：优化灌溉）和三种施肥处理（N1：传统施肥、N2：Expert - N系统推荐的最佳施氮量、N3：最佳施氮量的80%）。采用EU - Rotate_N模型模拟土壤中水分和氮素的去向。结果表明，2000年和2001年，苋菜和菠菜在所有处理下的产量均无显著差异。然而，2001年W1N2和W1N3处理下的花椰菜产量明显降低。与W1处理相比，W2处理的灌溉量减少了27.9 - 29.8%，排水量减少了76%以上，水分利用效率提高了5 - 17%，灌溉水利用效率提高了29 - 45%。硝酸盐淋失是本研究中的主要途径之一，占总氮输入量的8.4%；与N1相比，N2和N3处理下的化肥氮输入量减少了66.5%以上，从而使气态氮减少了48 - 72%，氮素利用效率（NUE）提高了17 - 37%。此外，与W1处理相比，W2处理下的气态氮损失减少了18 - 26%，年平均NUE提高了22 - 29%。2000年最高年平均NUE出现在W2N3处理（169.6 kg/kg），2001年出现在W2N2处理（188.0 kg/kg）。我们发现优化施肥管理能使后续作物利用土壤中的残留氮。因此，我们建议向农民推荐W2N3管理方式，以减少蔬菜生产系统中的水分和氮素流失。
