春玉米积温稳定性及在发育期预报中的应用

Accumulated Temperature Stability of Spring Maize and Its Application to Growth Period Forecast

  • 摘要: 修正已有积温模型,提高积温稳定性,对积温指标更好地应用于农业生产实践有重要意义。基于东北地区春玉米的生长发育情况,综合分析影响积温稳定性的气象因素,订正常用的活动积温模型。在进行积温稳定性评价基础上,将订正模型应用于春玉米的发育期预报中。结果表明:温度条件是影响积温稳定性的最主要因素,基于温度因子得到的订正模型,在出苗-抽雄阶段和抽雄-成熟阶段较原模型年际间变异系数分别平均减小了0.42%和1.42%,订正模型计算的积温稳定性更好。分别利用1981-2010年及2011-2017年资料进行回代及预报检验,发现订正模型对抽雄期的预报结果改进不明显,对成熟期的预报结果误差较原活动积温模型在回代及预报检验中分别降低了3.78 d和1.1 d。

     

    Abstract: Northeast China is the largest spring maize production area in China and plays a vital role in ensuring food security. Temperature is an important environmental factor affecting agricultural production, especially for mid-high latitudes. Accumulated temperature, as a measure of heat, can be used to estimate the growth rate of crops, and the advance or delay of the growth period will affect the accumulation of dry matter in crops. Therefore, accurate forecast of maize growth period can promote current farming systems and management measures to ensure spring maize yield. As one of the most commonly used accumulated temperature calculation methods, the active accumulated temperature is refered to the accumulation of the average daily temperature over a period of time above a certain threshold, which is widely used in phenological period forecasting, agrometeorological disaster assessment, introduction of new varieties, and agro-climatic thematic analysis and zoning. The active accumulated temperature required for the growth period of the crop is not a constant. The relationship between crop development speed and temperature is not linear. Affected by the crop variety and environmental factors, the active accumulated temperature reflects the instability to influence application effect. Therefore, it is of great significance to modify the existing accumulated temperature models and improve the stability of accumulated temperature for better application. Based on the growth and development of spring maize, 5 agrometeorological stations in Northeast China, Hailun, Dunhua, Changling, Kuandian and Zhuanghe are selected to comprehensively analyze the meteorological factors affecting the stability of accumulated temperature and to revise the widely used active accumulated temperature model. After evaluating its effect, the revised model is applied to the growth period forecast of spring maize. Results show that due to its important role in affecting the stability of the accumulated temperature, the temperature is the key factor considered in the model revision. The revised model improves its stability and reduces variation coefficients in the emergence-heading period and the heading-maturation period by 0.42% and 1.42%, respectively. Using data in 1981-2010 for hindcast and data in 2011-2017 for forecast test, compared with the original active accumulated temperature model, the forecast error in revised model during the mature period is reduced by 3.78 d and 1.1 d. The revised model does not improve the forecast of the heading period.

     

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