长期施肥对塿土冬小麦产量及土壤养分的影响

Effects of Long-term Fertilization on Winter Wheat Yield and Soil Nutrients in Rainfed Loess Soil

以20年塿土冬小麦-夏休闲轮作体系长期肥料定位试验为平台,探讨长期施肥对小麦产量及土壤养分的影响。结果表明:同时施入氮磷肥处理(NP、NPK、MNPK)小麦产量上升趋势显著,年均增产幅度为219~265 kg hm^(-2),平均产量均为CK的3倍。化肥配施有机肥(MNPK)土壤有机质、全氮、全磷、速效磷和速效钾含量均呈明显上升趋势,年均分别增加0.93g kg^(-1)、0.05 g kg^(-1)、0.07 g kg^(-1)、12.11 mg kg^(-1)、8.8 mg kg^(-1),有机质和全磷的平均含量较CK分别提升59%、73%,速效磷和速效钾平均含量为CK的13.6倍和1倍。氮磷配施(NP、NPK)土壤有机质平均含量较CK增加18%和16%。施氮肥对土壤中全氮含量没有明显影响。施磷肥(NP、PK、NPK)土壤全磷以及速效磷含量逐年显著上升,土壤全磷平均含量较CK提升27%,速效磷含量为CK的4倍。施钾肥(NPK、NK、PK)对土壤全钾含量没有明显影响,但土壤速效钾上升趋势显著,年均增幅为5.6~6.9 mg kg^(-1),平均含量较CK分别增加38.8%、59.3%和48.1%。旱作塿土合理的施肥措施为有机肥配合氮肥。

The aim of this research was to investigate the effects of long-term fertilization on winter wheat yield and soil nutrients in the long-term fertilizer trial of rain-fed loess soil for 20 years in Guanzhong Plain, Shaanxi Province,China. Combined applications of nitrogen（N） and phosphorus（P） fertilizers（NP, NPK, MNPK） significantly increased the winter wheat yield and the increments of mean annual yield ranged from 219 to 295 kg hm^-2. The mean annual yield was 3 times in the treatments of NP, NPK and MNPK than that of control（CK）. The application of organic manure combined with NPK（MNPK） significantly raised the contents of soil organic matter（SOM）, total N（TN）, total P（TP）, available P（AP） and available potassium（AK）, and their mean annual increments were 0.93 g kg^-1, 0.05 g kg^-1,0.07 g kg^-1, 12.11 g kg^-1 and 8.8 g kg^-1, respectively. The annual mean contents of SOM and TP were, respectively,59% and 73% higher and those of AP and AK were, respectively, 13.6 times and 1 time in MNPK than in CK treatment. The content of SOM was 18% and 16% higher, respectively, in the treatments of NP and NPK than in the treatment of CK. The application of N fertilizer had no significant effect on soil TN content. However, the application of P fertilizer resulted in significant increase in the content of soil TP and AP. The mean annual content of soil TP was 27% higher, and the mean annual content of soil AP was 4 times in the treatments of NP, PK and NPK than in the treatment of CK. On the other hand, the application of K fertilizer had no significant effect on the content of soil TK.The content of soil AK showed increase trend with years. The mean annual increments of AK ranged from 5.6 to 6.9 mg kg^-1, and the mean content of soil AK was, respectively, 38.8%, 59.3% and 48.1% higher in the treatments of NPK, NK and PK than in the treatment of CK. In summary, the application of organic manure combined with N fertilizer was the best fertilization measure in loess soil.