中国农业科学 ›› 2014, Vol. 47 ›› Issue (24): 4858-4867.doi: 10.3864/j.issn.0578-1752.2014.24.009

• 土壤肥料·节水灌溉·农业生态环境 • 上一篇    下一篇

几种保护措施对红壤坡地水文过程及干旱的影响

林丽蓉1,陈家宙1,王 峰1邓盛华2   

  1. 1华中农业大学资源与环境学院/农业部长江中下游耕地保育重点实验室,武汉 430070
    2重庆市永川区农业综合开发项目管理中心,重庆 402160
  • 收稿日期:2014-08-26 出版日期:2014-12-16 发布日期:2014-12-16
  • 通讯作者: 陈家宙,Tel:027-87283960
  • 作者简介:林丽蓉,Tel:027-87283960;E-mail:lrlin@mail.hzau.edu.cn
  • 基金资助:
    国家自然科学基金(41271240)、中央高校基本科研业务费专项资金(2011QC044)、湖北省自然科学基金(2011CDC069)

Several Conservation Practices Influencing the Hydrologic Processes and Drought of the Red Soil Sloping Farmland

LIN Li-rong1, CHEN Jia-zhou1, WANG Feng1, DENG Sheng-hua2   

  1. 1College of Resources and Environment, Huazhong Agricultural University/Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, Wuhan 430070
    2 The Administrative Center of Comprehensive Agricultural Development Projects, Yongchuan, Chongqing, Chongqing 402160
  • Received:2014-08-26 Online:2014-12-16 Published:2014-12-16

摘要: 【目的】中国亚热带红壤坡地的农业生产受水蚀与季节性干旱双重影响,水蚀与季节性干旱之间的水文联系仍然不明确。本研究探索农田常用保护措施如何影响红壤坡地的雨旱季水文过程和土壤-作物水分胁迫,为更有针对性地选择农田管理措施提供依据。【方法】 2008—2010年在湖北咸宁第四纪红色粘土母质发育的红壤8°坡地上开展大田试验,设置无保护措施或对照(CK)、牧草带(GS)、地表施用聚丙烯酰胺(PAM)、地表覆盖稻草(SM)4种处理,第一年和后两年分别以花生(白沙1018)和玉米(登海3632)为供试作物,研究不同处理的地表产流和产沙、土壤储水、土壤-作物干旱、作物产量。【结果】当降雨量相近时,降雨强度越大产流、产沙量一般也越大;总体上,产流、产沙量均为CK>PAM>GS>SM,4种处理的水蚀程度依次降低;与CK比较,3种保护措施平均减少产流量36.6%,减少产沙量52.7%,减少产沙量的作用更明显。0—45 cm土壤储水量动态变化在雨旱季的特征明显不同。总体上,土壤储水量在雨季呈升高趋势,在旱季呈下降趋势;处理间差异随降雨持续而减小,随无雨期延长而增大。雨旱季土壤储水量最高的和波动变化最小的均为SM处理,其次是PAM处理,GS和CK处理的土壤储水量最接近。旱季持续干旱阶段,0—15 cm土壤干旱程度D值随土壤干旱的持续逐渐增大;两年D值均为CK>GS>PAM>SM,4种处理的土壤干旱程度依次减小。受气候、作物生长期及保护措施的共同影响,作物胁迫积温SDD值的增加过程及处理间差异的变化都表现出明显的阶段性,整个旱季的SDD值均为CK>GS>SM和PAM,4种处理的作物水分胁迫依次减小。作物产量是SM和PAM>GS和CK。与CK比较,GS、PAM、SM 3种处理分别使2008年的花生增产19.3%、33.0%、27.3%;对于2009年的玉米产量,GS处理减产0.5%,PAM、SM处理分别增产17.1%和36.3%。不同保护措施对干旱的影响不同,GS因自身耗水而不能明显缓解土壤-作物干旱;PAM主要通过减少蒸散发来减轻土壤-作物干旱;SM明显增加土壤雨季储水和减少旱季土壤水分耗失,因此有效缓解土壤-作物干旱。【结论】GS、PAM、SM 3种农田保护措施在红壤坡地上都能够阻控水蚀和缓解季节性干旱,但作用途径、特点、程度不同,雨季减少产流量和增加土壤储水量的作用有限,增加雨季土壤储水的作用小于其减轻旱季土壤-作物水分胁迫的作用。

关键词: 农田保护措施, 土壤-作物干旱, 水文过程, 红壤

Abstract: 【Objective】 In subtropical China, agricultural production of the red soil sloping land is limited by water erosion and seasonal drought. The hydrological relationships between water erosion and seasonal drought are not well understood. The objective of this study was to explore how field commonly used conservation practices influence the hydrologic processes in rainy and dry seasons and the soil and crop water stress in the red soil sloping land, and to provide a theoretical basis for selecting more pertinent field management practices. 【Method】 From 2008 to 2010, a field experiment was conducted in Xianning, Hubei. The zonal soil was red soils (Ultisols), developed from the Quaternary red clay. The experiment field is a typical low hill with a slope of 8°. Four treatments were used in the experiment plots, including no-conservation practice or control treatment (CK), grass strip (GS), application of polyacrylamide on the soil surface (PAM), and mulching the soil surface with rice straw (SM). Peanuts (Arachis hypogaea L., Baisha 1018) and maize (Zea mays L., Denghai 3632) were planted in the first and the next two years, respectively. The surface runoff amounts, sediment yields, soil water storages, soil and crop drought, and crop yields among the four treatments were studied. 【Result】 When rainfall amounts were close, surface runoff amounts and sediment yields generally increased with the rising rainfall intensities. As a whole, surface runoff amounts and sediment yields were in the same declining order of CK>PAM>GS>SM, indicating the four treatments reduced water erosion by different degrees. Compared with the CK, the three conversation practices reduced surface runoff amounts and sediment yields by about 36.6% and 52.7% on average, respectively, with more significant decreases in the sediment yields. Soil water storage dynamics in the 0-45 cm depth were obviously different between the rainy and dry seasons. In general, the water storages rose up in rainy seasons, while gradually reduced during dry seasons. In addition, the differences among the four treatments turned to be smaller and smaller in persistent rainfalls, however they became larger and larger during rain free periods. Both in rainy and dry seasons, the SM had the highest soil water storage and the least fluctuation, followed by the PAM. GS and CK had close water storages. Values of soil drought degree (D) in the 0-15 cm depth gradually increased during the continuous drought in dry seasons. Both in the two years, D values were in the declining order of CK>GS>PAM>SM, suggesting that soil drought degrees in the four treatments declined in turn. Under the influences of climate, crop growing periods and conversation practices, the increases in stress degree day (SDD) and the variability in differences among treatments appeared obvious periodicity. In the whole dry season, values of SDD were all in the reducing order of CK>GS>SM and PAM, showing that crop water stresses in the four treatments reduced in sequence. SM and PAM had larger crop yields than GS and CK. Compared to the CK, the GS, PAM and SM separately increased peanut yields by 19.3%, 33.0%, and 27.3% in 2008. While in 2009, the GS reduced maize yield by 0.5% and the PAM and SM separately increased maize yields by 17.1% and 36.3%. Different conversation practices had different kinds of impacts on the drought. For example, the GS didn’t greatly relieve soil and crop drought for its water consumption. The PAM reduced soil and crop drought mainly by reducing the loss of evaporation. The SM markedly increased soil water storage in rainy seasons, and greatly reduced soil moisture loss in dry seasons, and therefore significantly alleviated soil and crop drought. 【Conclusion】When applied in the red soil sloping farmland, all the three conservation practices of GS, PAM, and SM could reduce water erosion and alleviated seasonal drought in different ways, with different characteristics and degrees. In rainy seasons, the three conservation practices reduced surface runoff amount and increased soil water storage only by limited volumes. The function in increasing the soil water storage in the rainy season was smaller than that in alleviating the soil and crop water stress in the dry season.

Key words: field conservation practices, soil and crop drought, hydrologic process, red soil