动态种植密度条件下制种玉米耗水监测与模拟

The imbalance between supply and demand of water resources is serious in the Shiyang River Basin, a typical inland arid basin in northwest China. Compared with the normal corn planting system, planting seed corn is more effective to raise farmers' income, hence is well developed in integrated management for the Shiyang River basin. But plant height of male parent and female parent is different, the male parent of the seed corn needs to be removed in the late growth stage, which results in heterogeneity in spatial distribution of water consumption. Regulation of planting density is an effective method for water saving and high yield. This research project will monitor and analyze water consumption processes of seed corn under different planting density, using large-scale weighing lysimeter method, eddy covariance method and water balance method. The potential achievements from the research project will be: (1) the rules of water consumption and crop coefficient changes under different weather condition, growth period and planting density conditions; (2) the difference of water consumption between seed corn and normal corn; (3) the effects of different planting density conditions on physiological and ecological index, yield and composition elements; (4) the response relationship of water-yield in different planting density condition and the water production function of seed corn; (5) A seed corn water consumption estimation model considering shading and cover change will be built and a water consumption conversion method in field scale will be established for seed corn, based on the actual water consumption data and comparison of estimation accuracies between the Penman-Monteith, Shuttleworth-Wallance and C models. The research results will provide a scientific basis for formulating a high efficient irrigation model and planting system for seed corn in this basin.

石羊河流域水资源供需矛盾十分突出。在流域综合治理中，制种玉米因其相对于普通玉米更能促进农民增收而得到大力发展，但父母本株高明显不同，生育后期需去除父本，耗水空间分布存在异质性。调控种植密度是节水高产的有效方法。本项目采用大型蒸渗仪法、涡度相关法、茎流计法、水量平衡法等监测不同种植密度条件下制种玉米的耗水过程。研究不同天气、不同生育期、不同种植密度下制种玉米耗水规律，研究其作物系数变化规律，对比制种玉米与普通玉米的耗水差异。分析不同种植密度对制种玉米生理生态指标、产量及构成要素的影响。研究不同种植密度条件下制种玉米水分-产量响应关系，获得制种玉米的水分生产函数。以实测耗水资料为标准，对比Penman-Monteith模型和S-W模型、C模型等的估算精度，构建考虑遮阴与覆盖变化的制种玉米耗水估算模型，确立农田尺度制种玉米耗水转换方法。研究结果将为制定制种玉米节水高效灌溉模式与制度提供科学基础。

石羊河水资源供需矛盾十分突出，在流域综合治理中，制种玉米相比于普通玉米更能促进农民增收且该地区的气候条件适宜制种业，所以得到了大力发展。制种玉米父母本株高差异显著，生育期后期需去除父本，耗水存在空间异质性，调控种植密度是节水高产的有效方法。.本项目采用大型蒸渗仪法、涡度相关法、茎流计法、水量平衡法等方法连续四年在中国农业大学石羊河试验站开展不同密度、不同密度和水分耦合作用下制种玉米田间试验。获得了不同密度及水分对玉米株高、叶面积、茎粗等生理指标、产量及其构成要素和品质等的影响。摸清了不同天气、不同生育期、不同密度条件下制种玉米耗水规律，建立不同密度条件下制种玉米作物系数数学表达，对比制种玉米与普通玉米的耗水差异。揭示了制种玉米父本母本植株特性和耗水特性的差异，确定叶面积指数为制种玉米单株液流的尺度转换因子，实现单株到农田ET的尺度提升。建立了考虑父本母本混种及土壤多组分组合的作物系数法，并构建考虑父本母本相邻行光能截获划分的多源模型，实现制种玉米父本母本ET的精确划分。获得了不同种植密度条件下制种玉米水分-产量响应关系与水分利用效率，水分利用效率随着种植密度和作物耗水量的增加呈抛物线趋势。研究结果为制定制种玉米节水高效灌溉模式与制度、促进石羊河流域综合治理规划顺利执行提供科学基础。.在《Journal of Hydrology》、《Agricultural Water Management》、《Journal of Arid Land》等国内外期刊公开发表学术论文 7篇，其中SCI收录论文3 篇，另有一篇文章在《Journal of Arid Land》处于proofreading阶段，一篇在《灌溉排水学报》待刊；培养博硕士研究生7 人，已毕业5人。