Effects of long-term Fertilizer application on crop yields and stability

Chinese. 研究长期施肥处理对华北平原潮土作物产量及稳定性的影响，为维持田块尺度粮食高产、稳产、高效提供指导。采用长期定位试验中不同肥料处理与多种稳定性指数方法分析作物产量效应及稳定性。经过7年定位施肥试验，CK、P2K2、N2K2和N2P2处理的小麦产量分别为N2P2K2处理的25.5%、34.5%、43.3%和83.2%；玉米产量分别为42.3%、52.7%、70.6%和76.2%；不施氮肥，土壤氮自然供给力第1年降到59%，第2年为43%，此后稳定在40%左右；不施磷肥，土壤磷自然供给力第1年降至72%，第3年为55%，之后保持在55%左右；不施钾肥，土壤钾自然供给力第1年降为93%，第3年为76%，之后基本不变；7年累计，小麦、玉米及全年作物产量稳定性最强的处理分别为N1P2K2、N2P2K2和N1P2K2。作物产量效应与施肥量有明显相关性，产量稳定性与施肥量无明显关系，但与氮、磷、钾肥配比明显相关。

English. Yield response and its stability were studied in fluvo-aquic soil of North China Plain, and the result has provided a theoretical basis for high yield, stable production, high efficiency and sustainable development of grain production in field block scale. The different fertilization treatments and Multi-type Stability Index were adopted in long-term experiment for study of yield response and its stability. A 7-year fertilization experiment was carried out to study crop responses and yield stability in fluvo-aquic soil, North China Plain. The data indicated that for wheat the 7-year mean yields ratio of CK, P2K2, N2K2 and N2P2 treatments to N2P2K2 were 25.5%, 34.5%, 43.3%, 83.2%, and for maize 42.3%, 52.7%, 70.6% and 76.2%. N supply capacity of soil in the absence of N fertilizer declined to 59% of the original in the first investigated year, and down to 43% in the second year, and then fluctuated around 40% in the followed years, and without P fertilizer application, soil P supply capacity decreased to 72% in the first year, and down to 55% in the third year, after fluctuated around 55%. Finally, K supply capacity changed from 93% in the first year down to 76% in the third year of the experiment without K fertilizers. The best yield stability of wheat, maize and annual yield were the treatments of N1P2K2, N2P2K2 and N1P2K2. There were significant correlations between fertilizer application and yield response, between ratio of N, P, K and yield stability, but no obvious relationship between fertilizer application and yield stability.