基于产量反应和农学效率的苹果养分专家系统构建及验证

【目的】构建基于产量反应与农学效率的苹果养分专家施肥系统，通过田间试验验证其可行性，为我国苹果科学施肥提供新方案。【方法】搜集整理2002—2017年272个苹果田间试验数据，计算产量反应、养分内在效率、农学效率等参数，采用QUEFTS模型评估苹果养分吸收特征，建立基于产量反应和农学效率的苹果养分专家施肥系统。2017—2019年，在山西运城、陕西洛川和长武共选择12个盛果期‘红富士’苹果园开展田间验证试验，即采用苹果养分专家推荐施肥(Nutrient Expert,NE)、农民习惯施肥(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，研究苹果产量、氮肥利用效率及经济效益响应特征。【结果】苹果产量平均为33.91 t/hm²；苹果果实N、P、K含量分别为3.19、0.57、8.07 g/kg，枝条N、P、K含量分别为7.57、1.12、4.61 g/kg；叶片N、P、K含量分别为24.02、1.38、8.58 g/kg；地上部N、P、K养分吸收量分别为89.06、11.11、83.32 kg/hm...

Construction and validation of apple Nutrient Expert system based on yield response and agronomic efficiency

  【Objectives】  To develop an alternative for optimum fertilization in apple production systems, Nutrient Expert (NE) for apple fertilization based on yield response (YR) and agronomic efficiency (AE) was established, and its practicability was evaluated simultaneously using field experiments.   【Methods】  We collected the published results from 272 field experiments and calculated the data of several parameters such as YR, internal efficiency and AE from 2002 to 2017. The nutrient uptake of N, P, and K in apple was estimated by QUEFTS model, and NE was established based on YR and AE. Two-year field experiments (2017–2019) treated with NE, FP (farmers’ practice, FP), and ST (soil test, ST) were carried out in Luochuan and Changwu counties of Shaanxi Province, and Yuncheng county of Shanxi Province, and four apple orchards were selected in each county to investigate apple yield, nitrogen use efficiency (NUE), and economic benefits in response to NE, FP, and ST treatments.  【Results】  The averaged apple yield was 33.91 kg/hm2. The averaged N, P, and K concentrations were 3.19, 0.57, and 8.07 g/kg in apple fruit, 7.57, 1.12, and 4.61 g/kg in branches, and 24.02, 1.38, and 8.58 g/kg in leaves, respectively. The averaged N, P, and K uptakes in aboveground parts (i.e., fruit, branches, and leaves) were 89.06, 11.11, and 83.32 kg/hm2, and the harvest indices were 0.19 kg/kg for N, 0.27 kg/kg for P, and 0.48 kg/kg for K, respectively. The QUEFTS model indicated that nutrient uptake was linearly increased when apple yield reached 50%–60% of potential yield, and N 3.1 kg, P 0.4 kg, and K 2.9 kg were required to produce 1 t apple fruit, with a N: P: K ratio of 7.8:1.0:7.3. The yield response for N, P, and K was quadratically correlated with their respective AE, and the corresponding equation was AE_N=?0.0054YR_N2+1.767YR_N?0.056 (R2=0.804, n=270) for N, AE_P=?0.0053YR_P2+2.775YR_P+0.538 (R2=0.763, n=257) for P, and AE_K=?0.0036YR_K2+1.629YR_K+1.653 (R2=0.794, n=264) for K, respectively. The field experiment results revealed that the NE treatment substantially decreased the application rates of N-P-K fertilizers by 41.9%, 37.0%, and 43.6%, respectively. More importantly, apple yield, AE_N, PFP_N and economic benefit in NE were increased by 17.3%, 81.7%, 80.6%, and 21.9%, respectively, compared to the FP. Relative to the ST, the N-P-K fertilizers in NE were decreased by 20.8%, 25.0%, and 29.7%, respectively, while apple yield, AE_N, PFP_N, and economic benefits were comparable to that of ST.   【Conclusions】  Apple Nutrient Expert system based on yield response and agronomic efficiency was developed using QUEFTS model. Field experiments indicated that the apple Nutrient Expert system was a potentially multi-win strategy for optimizing apple fertilization, enhancing apple yield, and increasing NUE and economic benefits.