不同覆盖对土壤水热及冬小麦生长的影响

发布时间：2018-04-14 00:11

本文选题：覆盖 + 土壤水热　；参考：《西北农林科技大学》2017年硕士论文

【摘要】：我国西北干旱半干旱地区,干旱少雨,地表采用不同材料进行覆盖能够调控土壤温度,增加土壤有效蓄水量,提高水资源利用效率,增加作物产量。试验于2015年10月~2016年5月在西北农林科技大学中国旱区节水农业研究院进行,采用遮雨棚下地埋式土柱进行冬小麦生长控水试验,共设10个试验处理,每个处理三组重复,分别为砂石覆盖处理(GS)、白膜全覆盖处理(WF)、WF+1mm秸秆处理(WS)、黑膜全覆盖处理(BF)、BF+1mm秸秆处理(BS)、长度分别为1mm、1cm、5cm和10cm的秸秆覆盖处理(S1、S10、S50和S100)以及不覆盖对照处理(CK)。基于小型蒸渗仪实测土柱质量变化动态,对比研究了单、双作物系数法计算的冬小麦蒸散发量;并运用HYDRUS-1D模型对冬小麦土壤水分进行模拟,结合不同覆盖下冬小麦生长过程的差异,得出以下主要结论:(1)不同覆盖处理均明显影响了冬小麦土壤贮水量和土壤水分的动态变化过程:总体来看,秸秆覆盖的蓄水保墒效果好于覆膜处理,砂石覆盖的蓄水保墒效果介于二者之间;在覆盖厚度不变的情况下,在0~10cm秸秆长度内,秸秆长度越大,抑制土壤蒸发效果越明显;黑膜系列的覆盖处理在抑制土壤蒸发方面好于白膜覆盖,同种颜色地膜覆盖处理下,上膜下秸覆盖处理保水效果好于单一覆膜处理;所有覆盖措施相较于对照而言,均不同程度地抑制了土壤蒸发,提高了土壤含水量。从整个生育期来看,秸秆覆盖处理和砂石覆盖具有增温和降温的双重作用;覆膜处理总体表现为增温效应;黑膜系列覆盖较白膜系列覆盖增温幅度小,同种颜色地膜覆盖下上膜下秸的增温效应比单一覆膜处理的增温效应明显。(2)覆盖处理总体上延长了冬小麦的物候期。随着秸秆长度的增大,冬小麦物候期有延后的趋势;黑膜覆盖生育期略长于白膜覆盖,对于上膜下秸和单一覆膜处理,前者生育期晚于后者。(3)各覆盖处理下冬小麦株高和叶面积均显著增加。覆膜和覆砂条件下冬小麦株高高于秸秆覆盖,秸秆处理中各长度下的冬小麦株高无明显规律,白膜覆盖下冬小麦株高高于黑膜覆盖,上膜下秸与单一覆膜处理对比不明显;秸秆覆盖下冬小麦叶面积指数大于覆膜和覆砂条件下,且5cm和10cm长度的秸秆覆盖下冬小麦叶面积指数在生长中后期明显大于其他覆盖处理。利用Logistic生长曲线能够很好地实现对冬小麦叶面积指数和株高的生长变化的动态模拟,构建出各种处理下的冬小麦叶面积指数和株高的曲线回归方程,各处理下冬小麦的生长过程符合S型曲线。(4)各覆盖处理由于增加了冬小麦穗数,因而有效地提高了产量,但对千粒重和穗长无明显影响;各覆盖处理均不同程度地提高了冬小麦水分利用效率(WUE),且秸秆长度越大,WUE越大;黑膜处理比白膜处理的WUE大,砂石覆盖的WUE介于二者之间。(5)基于单、双作物系数法计算所得的蒸散发量总体上小于实测值。校正后拟合效果较好,且双作物系数法拟合效果明显好于单作物系数法;相较于不覆盖处理,覆盖后单、双作物系数法拟合效果更好;秸秆覆盖处理中,秸秆长度越大,拟合效果越好。(6)HYDRUS-1D模型对覆砂和覆膜条件下冬小麦土壤水分的模拟效果较好,较好地反映出了冬小麦生育期内土壤贮水量的动态变化,说明在覆膜和覆砂条件下,HYDRUS模型仍然具有一定的适用性。
[Abstract]:China's northwest arid and semi arid areas, drought, surface covered with different materials can regulate soil temperature, increase soil water storage capacity, improve the utilization efficiency of water resources, increase crop yield. Experiments were carried out in Northwest Agriculture and Forestry University China arid Institute of water saving agriculture in October 2015 ~2016 year in May, the cover is buried in soil column under the canopy the winter wheat growth and water controlling experiments were divided into 10 treatments, each treatment group were repeated three, gravel mulch treatment (GS), albuginea coverage treatment (WF), WF+1mm (WS), black straw mulch treatment (BF), BF+1mm (BS), straw length were 1mm 1cm, 5cm, and 10cm straw mulching (S1, S10, S50 and S100) and no mulching treatment (CK). The small lysimeter soil column quality dynamic change based on the comparative research of single and dual crop coefficient of winter wheat evapotranspiration calculation method The amount of fat; and use the HYDRUS-1D model to simulate the soil moisture in winter wheat, with the growth of Winter Wheat under different mulching, the main conclusions are as follows: (1) different mulching treatments were significantly affected the winter wheat soil water storage and soil moisture in the process of change: Overall, straw mulching and water retention effect in the film processing, between sand covered water retention effect between the two; in the cover thickness unchanged in 0~10cm stalk length, stalk length, restraining soil evaporation effect is obvious; the black film series covered in the inhibition of soil evaporation in white cover, same color film mulching treatment membrane under straw mulching, water treatment effect is good in a single film; all coverage measures compared to the control, inhibited the soil evaporation, increase soil water content. In the entire growing period, straw mulching and gravel mulching has the dual role of mild cooling; film mulching generally shows warming effect; black film series cover a series of albuginea coverage for increase of temperature range is small, the warming effect of the same color film under the straw mulching under the warming effect than single treatments significantly. (2) the overall coverage extended the phenological period of winter wheat straw. With the increase of the length of the winter wheat phenology postponed trend; black film growth period is slightly longer than white cover, for membrane under straw mulching treatment and single growth period, the former is later than the latter. (3) under different mulching treatments the winter wheat plant height and leaf area were significantly increased. And the sand covered under the condition of winter wheat plant height was higher than that of straw mulching, straw processing under different lengths of winter wheat plant height had no obvious regularity, white film covered under the winter wheat plant height was higher than that of black film That film under the straw mulching treatment compared with the single is not obvious; under Straw Mulching Winter Wheat Leaf area index is larger than the sand covered and under the conditions of 5cm and 10cm, and the length of the straw mulching under the winter wheat leaf area index in the late growth is significantly greater than other mulch treatments. Using the Logistic growth curve can achieve good dynamic simulation of the growth of winter wheat leaf area index and plant height, construct the winter wheat leaf area index of different treatment conditions and the height of the curve regression equation, the growth process of Winter Wheat under different treatments with S curve. (4) the covered reasons to increase the spike number, thus effectively to increase the yield, but had no significant effect on 1000 grain weight and panicle length; different mulching treatments increased the water use efficiency of Winter Wheat (WUE), and the straw length is larger, more than WUE; WUE treated with white black film, sand Between the coverage of WUE between the two. (5) based on the calculated evapotranspiration, dual crop coefficient hair is generally less than the measured value. The better fitting effect after correction, and the effect coefficient method of double crop is obviously better than the single crop coefficient method; compared with no mulch treatment, after covering single and dual crop better the fitting effect coefficient method; straw mulching, straw length is bigger, better fit. (6) the simulation results of HYDRUS-1D model for winter wheat soil water and sand mulching conditions, can better reflect the dynamic changes of soil water content during winter wheat growth period, in the film and coated sand under the condition, the HYDRUS model still has certain applicability.

【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S152;S512.11

【参考文献】