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为探明不同宽度沟垄集雨种植下土壤呼吸对土壤水热因子的响应机制,对比研究了沟垄比分别为20 cm∶40 cm(P40)、30 cm∶30 cm(P30)、40 cm∶20 cm(P20)的沟垄集雨种植和平作种植(CP)下冬小麦的土壤呼吸动态变化,及其与土壤温度和水分的关系.结果表明,4个处理的土壤呼吸速率在越冬期最低,返青期开始升高,扬花期前后达到峰值,之后逐渐降低.沟垄集雨处理土壤呼吸速率表现为P40>P30>P20,垄宽增加使呼吸速率提高1.2%~18.4%;苗期和越冬期,沟垄集雨种植提高了土壤呼吸速率,表现为P40>P30>P20>CP,其中苗期3个沟垄集雨处理均显著高于CP(P<0.05),越冬期P40处理显著高于CP;苗期和越冬期沟垄集雨种植提高了土壤温度,拔节期至成熟期CP土壤温度高于沟垄集雨处理;沟垄集雨种植能有效蓄水保墒,随着垄宽的增加集雨效果越好,苗期至拔节期降雨稀少,7.6 cm和12 cm土层土壤含水量均表现为P40>P30>P20>CP.相关分析表明,土壤呼吸与温度的相关系数达极显著水平(P<0.01),P40和P30的土壤呼吸与水分的相关系数小于P20和CP;水热双因子二次方程模型能解释呼吸变化的61.7%~74.1%,温度指数模型能解释50.3%~68.2%.本研究结果为沟垄集雨种植的生态效益评估提供理论依据.
In order to find out the response mechanism of soil respiration to soil hydrothermal factors under the furrow-furrow planting with different widths, the furrow-to-furrow ratio of 20 cm to 40 cm (P40), 30 cm to 30 cm (P30) : The dynamic changes of soil respiration and their relationship with soil temperature and moisture under rainwater harvesting and flat planting (CP) of 20 cm (P20) , Returning to greening stage began to increase, reaching the peak before flowering stage, and then gradually decreased.The soil respiration rate of ridge-ridge rainwater harvesting treatment showed P40> P30> P20, and the increase of ridge width increased the respiration rate by 1.2% ~ 18.4% In the period, rainwater harvesting increased the soil respiration rate, which showed P40> P30> P20> CP. The rainwater harvesting of three furrows and furrows at seedling stage was significantly higher than that of CP (P <0.05) At the seedling stage and wintering period, ridge-ridge rainwater harvesting increased the soil temperature. The temperature of CP soil at jointing stage to maturity stage was higher than that of ridge and ridge rainwater harvesting. The furrow-ridge rainwater harvesting planting could effectively store water and soil moisture, The better the rain-harvesting effect was, the less rain was in the seedling stage and the jointing stage, and the soil moisture in 7.6 cm and 12 cm soil layers showed P40> P 30> P20> CP. Correlation analysis showed that the correlation coefficient between soil respiration and temperature reached extremely significant level (P <0.01). The correlation coefficient between soil respiration and water content of P40 and P30 was less than that of P20 and CP. The model can explain 61.7% -74.1% of the change in respiration and the temperature index model can explain 50.3% -68.2% .This study provides the theoretical basis for ecological benefit evaluation of furrow-furrow planting.