养分专家系统推荐施肥提高梨果产量及品质

  【目的】   养分专家系统推荐施肥方法是基于产量反应和农学效率的推荐施肥方法，简便易行。我们应用该方法进行了梨树的优化推荐施肥，并通过田间试验验证了该方法的可行性。   【方法】   在河北省保定市伍仁桥镇开展了3年 (2017—2019年) 田间实验，供试黄冠梨 (Pyrus bretschneideri Rehd. var. Huangguan) 采用养分专家推荐施肥 (Nutrient Expert，NE)、农户习惯施肥 (farmers’ practice，FP) 和当地农技部门测土配方推荐施肥 (soil test，ST) 3种施肥技术，研究黄冠梨叶片和果实氮磷钾养分含量、果实产量、主要品质指标、肥料农学效率、偏生产力及经济收益的变化。   【结果】   供试黄冠梨3年平均氮、磷和钾施肥量NE施肥处理与FP施肥处理相比分别降低35.96%、28.8%和57.92%。与FP施肥处理相比，NE施肥处理下叶片中的氮、磷含量3年平均分别增加了8%、26%，果实中的氮、磷、钾含量3年平均分别增加了26%、68%和18%。NE施肥处理梨果3年平均最高产量和产值分别为45.80 t/hm2和18.61万元/hm2，NE施肥处理的果实产量3年比FP与ST施肥处理分别增加了15.56%～26.91%和10.24%～15.23%；NE施肥处理3年经济效益比FP与ST施肥处理分别增加了17%～29%和11%～16%。与FP施肥处理相比，NE施肥处理3年果实中的平均可溶性糖含量和固酸比分别显著提高了27%和10%；与ST施肥处理相比，NE施肥处理下可溶性糖含量显著提高了21%。而其它果实品质如可滴定酸、可溶性固形物在3个施肥处理之间没有显著差异。同时，与FP施肥处理相比，虽然NE处理施肥量有所降低，而氮、磷、钾肥的3年平均农学效率和偏生产力分别提高了13.76、19.95、24.07 kg/kg和36.52、42.21、76.81 kg/kg。   【结论】   基于产量反应和农学效率的养分专家推荐施肥能够显著提高梨果产量、品质、肥料利用率及经济效益，证明该优化施肥方案适用于河北省梨树生产。但是在推荐方案中能否以部分有机肥替代无机肥，以及是否能长期维持土壤养分平衡等问题还需要进一步探究。

Fertilizer recommendation based on Nutrient Expert system to improves pear yield and quality

  【Objectives】   The Nutrient Expert System recommends fertilization based on yield response and agronomic efficiency, which is simple and easy to implement. In this study, we applied this method to optimize recommended fertilization for pear trees and verified the practicability of this method using field trials.   【Methods】   We conducted a 3-year fertilization experiment in Baoding City, Hebei Province, China, from 2017 to 2019 using the Chinese pear variety, Huangguan (Pyrus bretschneideri Rehd. var. Huangguan) as test material. The three fertilization regimes evaluated in this study were Nutrient Expert (NE), farmers’ practice (FP), and soil test (ST). We measured the leaf and fruit nitrogen (N), phosphorus (P) and potassium (K) concentrations, fruit yield and quality, fertilizer agronomic efficiency and partial productivity, and economic returns.   【Results】   Compared to FP, N, P and K fertilization rates in NE treatment decreased by 35.96%, 28.8% and 57.92%, respectively. Compared with FP treatment, the nitrogen and phosphorus content in leaves under NE treatment was increased by 8% and 26% on average in three years; the nitrogen, phosphorus and potassium content in fruits incrensed by 26%, 68% and 18% on average in three years. Under NE treatment, the average maximum yield and market value of pear fruits were 45.80 t/hm2 and RMB 186100 yuan/hm2. The fruit yield under NE treatment increased by 15.56%–26.91% and 10.24%–15.23% compared with FP and ST fertilization treatments. The economic benefits of NE treatment were increased by 17%–29% and 11%–16% compared with those of FP and ST fertilization. The average soluble sugars and ratios of soluble solids/titratable acids in 2017–2019 were significantly increased by 27% and 10% under NE treatment than FP treatment, and there was 21% higher soluble sugars under NE treatment than ST treatment. However, titratable acids, soluble solids were similar among FP, NE and ST treatments. Meanwhile, compared with FP, the agronomic efficiency and partial factor productivity of N, P and K fertilizers under NE treatment were increased by 13.76, 19.95, 24.07 g/kg and 36.52, 42.21 and 76.81 g/kg, respectively.   【Conclusions】   Our findings show that recommending fertilization based on the Nutrient Expert System can increase the yield response and agronomic efficiency of pear fruit plantations. We show that the Nutrient Expert System increased the yield, quality, fertilizer utilization and economic benefit of pear production, indicating that the optimized fertilization program is suitable for pear production in Hebei Province. However, in the recommended scheme, further research is needed to determine if inorganic fertilizers can substitute for organic fertilizers and whether soil nutrient balance can be maintained for a long time.