春小麦产量形成对干旱胁迫的响应模拟及补灌调控

With the global climate change and drought prone, threat of food security is more and more serious and challenges of grain food production is extremely severe in typical semi-arid region. How to conduct systematic evaluation of grain production and to eliminate and control in advance, the collaborative model of crop provide a feasible way to solve these problems. Based on the control experiment, combined with long-term location field experiment, and on collaborative model of formation process of wheat yield in dry land, the project research response of the spring wheat yield formation process under different drought stress. The response mechanism and effect of regulation will be researched by system engineering and the technology of data mining. To reveal: (1) The collaborative model is suitability for simulating spring wheat yield formation process, to improve the prediction accuracy under drought stress. (2)The exact threshold of drought stress will be determined by collaborative model, to reveal the response mechanism. (3) Supplementary irrigation scheme will be put forward to eliminate and control the process of spring wheat yield formation by establishing the optimal regulation model and calculating compensation effect of irrigation. These problems solved will be optimized restricted factors of spring wheat production, and provide a theoretical basis to realize evaluation, regulation of wheat potential regulation, accurate and efficient cultivation in dryland area.

随全球气候的变化和干旱频发，粮食安全受到越来越严重威胁，典型半干旱地区粮食生产面临的挑战尤为严重。如何对干旱环境下粮食生产进行系统评价，并进行预先消控，作物协同模型为解决此问题提供了可行途径。本项目拟基于调控试验，结合长期定位大田试验，以旱地小麦产量形成过程协同模型为平台，模拟不同干旱胁迫条件春小麦产量形成过程，并运用系统工程和数据挖掘技术研究春小麦产量形成过程对干旱胁迫的响应机制及调控效应。拟揭示：（1）干旱胁迫条件下春小麦产量形成协同模型模拟的适宜性，提高模型在干旱环境中的预测精度。（2）利用模型确定春小麦产量形成过程中干旱胁迫的精确阈值，揭示春小麦产量形成对干旱环境的响应机制；（3）建立优化调控模型，计算灌水的补偿效应，提出补偿干旱胁迫春小麦产量消减的补灌方案。这些问题的解决无疑会对优化半旱地区制约春小麦生产的限制因素，实现旱地小麦潜力评估、调控以及精准高效栽培提供理论依据。

本研究基于APSIM模型，结合定西市安定区安家坡村长期大田调控试验，研究旱地春小麦产量形成过程对干旱胁迫的响应机制及调控效应。主要研究结论有：（1）APSIM模型对模拟干旱胁迫条件下旱地春小麦产量形成具有较好的适宜性，模拟小麦生育期、地上生物量、籽粒数、千粒重、产量、以及土壤水分含量的均方根误差分别为2.79d、373.25kg·hm-2、259.99number·m-2、2.07g、225.41kg·hm-2、1.97%，归一化均方根误差分别为2.11%、6.26%、2.32%、8.14%、7.80%、12.34%，模型有效性指数分别为0.82、0.66、0.84、0.68、0.71、0.74。（2）确定了不同生育期干旱胁迫对研究区旱地春小麦产量影响大小分别为：拔节期>灌浆期>抽穗期>开花期>出苗期>无胁迫>分蘖期。（3）确定了不历时干旱胁迫对小麦产量形成的影响。出苗期-抽穗期干旱胁迫对春小麦籽粒数的影响最大，春小麦平均籽粒数最低为3160.32 number·m-2。拔节期-灌浆期干旱胁迫对春小麦千粒重的影响最大，春小麦平均千粒重最低为28.66 g。出苗期-抽穗期干旱胁迫对小麦产量影响最大，春小麦平均产量最低为1273.96 kg·hm-2。（4）利用逐步多元回归方程确定了不同干旱胁迫条件下，小麦生长过程中的最佳灌水天数和灌水量以及对应的产量。其中出苗后第1、47、60、82、86天，且总灌水量为343.09 mm时，小麦产量达最大值5578.91 kg·hm-2。研究结果对揭示半干旱地区水分限制因素条件下，旱地春小麦潜力评估和调控等方面都具有重要的意义和应用价值，为旱作小麦精准高效栽培提供理论依据。