Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, China Agricultural University, Beijing, China.
College of Horticulture, Henan Agricultural University, Zhengzhou, China.
PLoS One. 2018 Sep 27;13(9):e0204570. doi: 10.1371/journal.pone.0204570. eCollection 2018.
Excessive fertilization is a common agricultural practice that often negatively influence soil and environmental quality in intensive vegetable production systems in China. To reduce negative effects of excessive fertilization, current studies generally focused on fertilizer management but not irrigation. In this study, we investigated the effects of fertilization and irrigation on soil properties, leaching water characteristics, plant growth, cucumber yield, irrigation water use efficiency (IWUE) and partial factor productivity of nitrogen (PFPN) in a double cropping system. The treatments included (i) conventional irrigation with conventional N fertilization (IcNc), (ii) optimal irrigation with conventional N fertilization (IoNc), (iii) conventional irrigation with optimal N fertilization (IcNo), and (iv) optimal irrigation with optimal N fertilization (IoNo). In general, fertilization merely influenced concentrations of nitrate (NO3-), phosphorus (P) and potassium (K), but did not affect most leaching water characteristics. In contrast, irrigation influenced pH, EC and concentrations of P, K, Ca, Mg, Na and Cu. Cumulative leached amounts of NO3-, P, K, Ca, Mg, Na, Fe, Cu and Zn were significantly decreased by optimal irrigation as compared to conventional irrigation under same fertilization conditions, but not by optimal fertilization as compared to conventional fertilization under same irrigation conditions. The leachate volume was strongly positively correlated with cumulative leached amounts of all tested elements, and these relationships were obviously influenced by irrigation but not fertilization. The IoNo treatment significantly increased both IWUE and PFPN as compared to the IcNc treatment. However, the IcNo treatment only enhanced PFPN, while the IoNc treatment improved IWUE, when compared to the IcNc treatment. Our results suggested that irrigation has more influence than fertilization on leaching water quality and that the optimal irrigation combined with optimal fertilization was efficient in reducing the potential environmental risk caused by excessive fertilization in intensive vegetable production systems.
过量施肥是中国集约化蔬菜生产系统中常见的农业实践，通常会对土壤和环境质量产生负面影响。为了减少过量施肥的负面影响，当前的研究通常集中在肥料管理上，而不是灌溉上。在这项研究中，我们调查了施肥和灌溉对土壤特性、淋溶液特性、植物生长、黄瓜产量、灌溉水利用效率（IWUE）和氮的偏生产力（PFPN）的影响，在复种系统中。处理包括（i）常规灌溉与常规 N 施肥（IcNc），（ii）最佳灌溉与常规 N 施肥（IoNc），（iii）常规灌溉与最佳 N 施肥（IcNo），和（iv）最佳灌溉与最佳 N 施肥（IoNo）。一般来说，施肥仅影响硝酸盐（NO3-）、磷（P）和钾（K）的浓度，但不影响大多数淋溶液特性。相比之下，灌溉影响 pH 值、EC 和 P、K、Ca、Mg、Na 和 Cu 的浓度。与常规灌溉相比，在相同施肥条件下，最佳灌溉可显著减少 NO3-、P、K、Ca、Mg、Na、Fe、Cu 和 Zn 的累积淋失量，但在相同灌溉条件下，最佳施肥不会减少 NO3-、P、K、Ca、Mg、Na、Fe、Cu 和 Zn 的累积淋失量。淋溶液量与所有测试元素的累积淋失量呈强正相关，这些关系明显受灌溉影响，而不受施肥影响。与 IcNc 处理相比，IoNo 处理显著提高了 IWUE 和 PFPN。然而，与 IcNc 处理相比，IcNo 处理仅提高了 PFPN，而 IoNc 处理提高了 IWUE。我们的结果表明，灌溉对淋溶液质量的影响大于施肥，最佳灌溉与最佳施肥相结合可有效降低集约化蔬菜生产系统中过量施肥造成的潜在环境风险。
