秸秆和地膜覆盖模式下土壤水热动态分析

采用减氮追肥、垄覆沟播、秸秆还田等措施种植冬小麦,研究其对冬小麦产量、土壤储水量、土壤水热动态变化过程及作物水分利用效率的影响。结果表明,不同处理之间土壤水分差异显著,不同土层土壤含水量既随降雨量波动,又受不同覆盖栽培条件的影响。"推荐施肥+垄覆沟播"模式0~100 cm土壤储水量最高。不同处理之间日间土壤温度差异较小,但温度日内变化差异较大。不同处理的增温效果为推荐施肥+垄覆沟播推荐施肥推荐施肥+夏闲秸秆。同对照相比,旱地"推荐施肥+垄覆沟播"模式使小麦增产5.25%,水分利用效率提高42.06%,是适合旱地作物生产的栽培措施。HYDRUS-1D模型模拟值同实测值拟合度较好,可用于不同覆盖模式下土壤水热过程分析。

Soil Water and Heat Dynamic Analysis Under Straw and Plastic Film Mulching Modes

A field experiment was conducted to investigate the effects of different covering cultivation modes on winter wheat yield, soil water storage, soil water and heat coupling processes and water use efficiency in the dry land of loess plateau. The experiment consisted of four treatments: conventional fertilization (CK), recommended fertilization (JN), recommended fertilization + straw mulching (JN+S), recommended fertilization + plastic film mulching on soil ridges and straw mulching in furrows (JN+PFM+S). The results showed that there are significantly different in soil moisture contents among all the treatments, and soil water content of different soil layers fluctuated with rainfall and was influenced by different covering cultivation modes. JN+PFM+S treatment had the highest water storage. Soil daily mean temperature differences were very small among all the treatments, but the intraday temperature changes were significantly different, and warming effects of different treatments were JN+PFM+S > JN > JN+S. Compared with the CK treatment, the wheat yield was increased by 5.25% and water use efficiency was increased by 18.85% in the JN+PFM+S treatment. In summary, JN+PFM+S treatment was considered to be suitable mode for the crop production in the local region. HYDRUS-1D model is capable of simulating soil water content dynamics well, so it can be used for analyzing soil water and heat processes between different covering cultivation modes.