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Accueil du site → Doctorat → Chine → 2017 → Plastic-film Mulching and Fertilizers Affect Growth and Soil CO_2 Emissions of Spring Maize in Dryland on the Loess Plateau,China

Northwest A&F University (2017)

Plastic-film Mulching and Fertilizers Affect Growth and Soil CO_2 Emissions of Spring Maize in Dryland on the Loess Plateau,China

刘乔斐

Titre : Plastic-film Mulching and Fertilizers Affect Growth and Soil CO_2 Emissions of Spring Maize in Dryland on the Loess Plateau,China

Auteur : 刘乔斐;

Grade : Doctoral Dissertation 2017

Université : Northwest A&F University

Résumé partiel
Food security problems,due to the fast-growing human population and loss of farmland,and climate change,caused primarily by increased concentrations of CO2 in the atmosphere,have become global issues that seriously threaten developing countries.The rain-fed farmland area is accounting for 50% of the total farmland area in China,approximately.It is essential for ensuring national food security.Maize(Zea mays L.)is one of the most popular grain crops in dryland areas.However,the maize grain yield in the area is always maintained at a low level due to the limited water resources.The grain yield production potential is not fully excavated.Therefore,there is still a long way to go to enhance the yield further,and shorten the yield gap in the future.In addition,the overuse of chemical fertilizers is a common problem during the maize production,resulting in decreased nitrogen(N)use efficiency,increased N losses and the risk of environmental pollution.Therefore,optimizing grain production system in dryland,improving grain yield and water/fertilizer use efficiency of maize,have a great important practical significance for protecting food security of the country in the future,and achieving the sustainable development of regional agriculture and environment.Accordingly,a 2-year field experiment was conducted in 2013-2014 years to investigate the effects of field management practices(six treatments : no mulching with urea,NU ;no mulching with controlled release fertilizers,CRFs,NC ;transparent plastic-film mulching with urea,WU ;transparent plastic-film mulching with CRFs,WC ;black plastic-film mulching with urea,BU ;black plastic-film mulching with CRFs,BC)on growth and soil CO2 emissions of spring maize in rain-fed farmland on the Loess Plateau,China.The main results of this study were concluded as follows :(1)Plastic-film mulching can increase topsoil temperatures and soil water contents.Early in the growing season,the soil temperatures was in the following order of,transparent plastic-film mulching(PMw)> black plastic-film mulching(PMb)> no mulching.Soil temperature was higher by 0.2–2.2℃ in the transparent mulching treatments than in the black mulching treatments.Late in the growing season,soil temperature was often higher in the no mulching treatments than in the mulching treatments.The soil water storage(SWS)was in the following order of,PMb>PMw>no mulching.In the upper 40 cm soil layers,about 6–20 mm soil water in all treatments was replenished at harvest time compared with that at sowing time in 2013.However,the soil water content in 2014 was decreased at the 120 cm soil layer compared with that at sowing time.(2)Mulching practices and urea types significantly affected the height,LAI and biomass grain yield of maize(P<0.05).A significant “mulching×urea”(P<0.05)interaction effect was also observed in these in two years.During the experimental years,the maize height was in the following order of,PMw>PMb>no mulching.LAI increased throughout the growing seasons,and peaked in mid-July in both years.Subsequently,LAI decreased because of leaf losses.In general,LAI under mulching treatments were higher than that under no mulching treatments.Early in the growing season,LAI under transparent plastic-film mulching treatments were higher than that under black ;Late in the growing season,LAI under black plastic-film mulching treatments were higher than that under transparent.Early in the growing season,the biomass grain yield of maize was in the following order of,PMw>PMb>no mulching ;However,late in the growing season,biomass grain yield of maize under black plastic-film mulching treatments were significantly higher than under other treatments(P<0.05).Biomass grain yield of maize under no mulching treatments were lowest during the whole growing stage of maize in both experimental years.Early in the growing season,there was no significant differences in the growth traits of maize under the two fertilization treatments ;However,late in the growing season,LAI and biomass grain yield of maize under CRFs treatments were higher than under urea treatments.(3)The mulching practices and urea types significantly affected the grain yield and water use efficiency(WUE)of maize in the two experimental years(P<0.05).Except NC plot in 2013,grain yield under CRFs treatments were significantly higher than under urea treatments(P<0.05).In general,the grain yield in 2014 were higher than in 2013.Compared with NU(9.18 t ha-1),yields in the WC,BC,BU,and WU plots in 2013 increased by 34.5%,32.4%,28.5%,and 13.4%,respectively,but yields in the NC plot decreased by 1.5%.In 2014,the highest yield was recorded in the BC plot(16.64 t ha-1),whereas the lowest was recorded in the control(13.18 t ha-1).WUE under PMb were significantly higher than that under PMw(P<0.05).ET was similar for all treatments in the two years(P>0.05

Mots clés : Loess Plateau of China; plastic-film mulching; controlled release fertilizer; soil CO2 emission; water use efficiency;

Présentation (CNKI)

Page publiée le 21 janvier 2018