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Accueil du site → Doctorat → Chine → 2013 → Effects Of Mulching Culture On Soil Thermal-moisture Status, Yield And Water Use Efficiency Of Corn In Semi-arid Area

China University (2013)

Effects Of Mulching Culture On Soil Thermal-moisture Status, Yield And Water Use Efficiency Of Corn In Semi-arid Area

Wang H L

Titre : Effects Of Mulching Culture On Soil Thermal-moisture Status, Yield And Water Use Efficiency Of Corn In Semi-arid Area

Auteur : Wang H L

Grade : Doctoral Dissertation 2013

Université : China University

Résumé partiel
Corn (Zea mays L.) is the third mainly crop (inferior to wheat and rice) in China. its plantingarea is increasing yearly from1949to nowadays. However, the cropland area is decreasing withthe development of economy and town expanding, resulted in the restricted area of corn, and theproductivity of corn is determined by unit yield solely. Recently, whole field surface plasticmulching and double ridge-furrow planting (PMF), a new technology increased corn yieldsignificantly, is applied widely in arid and semi-arid northwestern China. However, there has nosystemic research on the mechanism of improvement of PMF. To explore these, field experimentwere conducted in dingxi county of Gansu province during2009-2010, where locates at hilly andsemiarid northwest Loess plateau. Three treatments involved in the field experiment,1) wholefield surface plastic mulching and double ridge-furrow planting (PMF),2) whole field surfacesand mulching and flat planting (SM), and3) flat planting without mulching (CK), designedrandomly and replicated three times. Soil temperature, soil water storage, crop growth index, drymass, water consumption in different growth stages, water use efficiency, yield and yieldcomponent of corn were determined and analyzed. The main results are as follows:1. PMF increased soil average temperature about3℃in0-25cm soil profile duringSeeding-Heading stage of corn, as compare with CK, improved corn development in early growthperiod. Soil temperature of PMF was linear correlation with air temperature, but responsiblesensitivity was lower than SM and CK, especially in10-25cm soil profile. Therefore, PMF couldsustain relative stable soil temperature, benefit to corn development. SM also could improve andsustain relative stable soil temperature, but the impact was not significant as PMF.2. At the minimum soil temperature point, soil temperature gradient (Gra) of three treatmentswas positive, the deeper soil heat transported to surface. However, the Gra was opposed at themaximum soil temperature point. Before corn jointing, whether at the minimum or maximum soiltemperature point, Gra followed the sequence as PMF﹥SM﹥CK, soil thermal conductivity ofPMF was stronger than SM and CK. From corn jointing to harvest, Gra followed the sequence asPMF﹥SM﹥CK at the minimum soil temperature point, and followed the sequence as PMF<SM<CK at the maximum soil temperature point, then, it suggested that soil thermal conductivity of PMF was stronger at lower soil temperature condition, weaker at higher soil temperature stage,plastic mulching adjust the characteristics of soil thermal conductivity, keep the relative stable soiltemperature, therefore, PMF improve corn growth, advance corn growth stage, shorten the wholegrowing stage, especially, extend the reproductive growth period, its benefit to corn filling.3. PMF could improve soil water storage in0-200cm profile and reduce evaporationsignificantly before corn jointing, enhance the soil water capacity, the more soil water sustainedfor later corn development. As compared with SM and CK, before corn jointing, PMF increasedsoil water storage by9.5mm and18.2mm in0-60cm soil profile, by13.7mm and9.6mm in60-120cm soil layer in2009, and by24.7mm and6.9mm in0-60cm soil layer, by8.6mm and14.2mm in60-120cm soil layer in2010, respectively. With the corn growth, there was a significant differencein water consumption between three treatments, which followed the sequence as PMF>SM>CK.Conversely, the change of soil water storage followed as CK>SM> PMF.After corn jointing, cornwater consumption accelerated, the most significantly stage was filling, then was the stage fromjointing to heading. During corn filling stage, as compared with SM and CK, water consumptionof PMF increased by72.0%and190.8%in2009, by84.5%and237.7%respectively in2010,during corn jointing-heading stage, water consumption of PMF increased by8.2%and23.9%in2009, by8.2%and37.8%respectively in2010. Thus, PMF could sustain a relatively better watercondition for corn reproductive growth. The water consumption peak was adaptive to thedynamics of precipitation. SM also could reduce evaporation and promote water use inreproductive growth period, but the effect was not significant as PMF.4. PMF increased soil temperature, soil water storage during corn growth early stage,increasd corn water consumption, therefore, improved leaf growth and biomass accumulation ofcorn. Leaf area index (LAI) of PMF was higher than SM and CK through whole corn growingstage and keep higher LAI in whole reproductive growth period, therefore, dry matteraccumulation of PMF was highest among three treatments, better vegetative growth supportreproductive growth and yielding. PMF and SM elongated reproductive growth period andaccelerate water consumption during corn reproductive stage, keep higher water use efficiencybiomass(WUEb) in whole reproductive growth period, benefit to the using of light, heat and water.

Mots clés : whole field surface plastic mulching and double ridge-furrow planting (PMF), wholefield surface sand mulching and flat planting(SM), soil water and heat, yield, water useefficiency(WUE), soil water ecosystem

Présentation (Globethesis)

Page publiée le 21 avril 2013, mise à jour le 10 janvier 2018