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Accueil du site → Doctorat → Chine → 2013 → Effects of Tillage and Nitrogen Fertilizer Management on Water Consumption Characteristics and Yield Formation in Dryland Farming Systems of Wheat

Shandong Agricultural University (2013)

Effects of Tillage and Nitrogen Fertilizer Management on Water Consumption Characteristics and Yield Formation in Dryland Farming Systems of Wheat

Duan Wen Xue

Titre : Effects of Tillage and Nitrogen Fertilizer Management on Water Consumption Characteristics and Yield Formation in Dryland Farming Systems of Wheat

Auteur : Duan Wen Xue

Grade : Doctoral Dissertation 2013

Université : Shandong Agricultural University

Résumé partiel
1Effects of tillage and nitrogen fertilizer on the water consumption characteristics andgrain yield formation in dryland farming systems of wheatThe field experiment was conducted in the hilly dryland region of the Bianhe village inLinzi, Shandong Province during the2009to2012growing seasons. The winter wheatcultivars Jimai22, Shannong16, and Yannong0428were used for the2009to2010,2010to2011, and2011to2012wheat growing seasons, respectively. The treatments included fourtillage patterns and six levels of N, which was applied before sowing. The tillage patternswere, namely, strip rotary tillage (SR), strip rotary tillage after subsoiling (SRS), rotary tillage(R), and rotary tillage after subsoiling (RS). The nitrogen treatments were six levels of Napplied before sowing:0,90,120,150,180, and210kg N ha1, designated as N0to N5,respectively. Subsoiling treatments were only conducted during the2009to2010growingseason.1.1Effects of tillage and nitrogen fertilizer rate on water consumption characteristics indryland farming systems of wheatUnder the same tillage condition, the amount of water consumption in the N3treatmentfrom jointing to maturity was significantly higher than that in N0, N1, and N2treatments. Bycontrast, no significant differences were observed in the water consumption of the N3and N4treatments from jointing to maturity. The N3treatment had the capability to absorb morewater from deep soil layers below100cm, as compared with the N0, N1, and N2treatments.The amount of soil water consumption and its ratio to the amount of total water consumptionwere significantly increased as the N rate increased from N0to N3. The amount of waterconsumed from deep soil layers below100cm did not significant change as the N rateincreased from N3to N5. The water potential of the flag leaf during the middle and late grainfilling stages in the N3treatment was not significantly different from the N4or N5treatments, but it was significantly higher than that of the N0, N1, and N2treatments. The soilevaporation after jointing in the N3treatment was not significantly different from that in theN4or N5treatments, but it was significantly lower than that in the N0, N1, and N2treatments.These results suggested that N3treatment allowed for sufficient soil water consumption indeep soil layers, with higher amounts of water consumed after jointing. The N3treatment alsoreduced the level of soil evaporation after the jointing stage.Under the same N rate condition, the soil water content before sowing with subsoilingwas increased after subsoiling in the first growing season. The amount of soil water consumedin the SRS and RS treatments were not significantly difference, but were significantly higherthan those in the SR and R treatments. This finding suggested that subsoiling improved theconsumption of soil water. The amount of water consumed from the sowing to the jointingstage in the SR and SRS treatments was significantly lower than that in the R and RStreatments. The amounts of water consumed from the jointing to the maturity stages in theSRS treatment were the highest, whereas the amounts in the R treatment were the lowest. Thesoil evaporation at various stages was significantly lower in the SR and SRS treatments thanin the R and RS treatments. The SRS treatment had the advantages of the improved use of soilwater by wheat and the reduced level of soil evaporation after jointing. This treatmentconsumed a larger amount of water amount after jointing, despite its lower amount of waterconsumption before jointing ; this trend was beneficial to meet the water demand afterjointing.1.2Effects of tillage and nitrogen fertilizer rate on carbon metabolism in drylandfarming systems of wheatUnder the same tillage conditions, the photosynthetic rate and SPS activity of the flag leafat the middle and late grain filling stages in the N3treatment were not significantly differentfrom those in the N4treatment. However, these rate and activity were significantly higherthan those in the N0, N1, and N2treatments, which promoted sucrose accumulation. Theseresults were reduced when the nitrogen application rate was increased in the N5treatment.During the2009to2010and the2011to2012growing seasons, the dry matter accumulationafter jointing in the N3treatment was not significantly different from that in the N4and N5treatments ; however, it was significantly higher than those in the N0, N1, and N2treatments. During the2010to2011growing season, the dry matter accumulation at maturity in the N3treatment was not significantly different as compared with that in the N4or N5treatment butwas significantly higher than that in N0, N1, and N2treatments. The dry matter accumulationafter anthesis in the N3and N4treatments was significantly higher than that in the other Ntreatments. The N3and N4treatments under the same tillage conditions likewise hadrelatively higher dry matter translocation after anthesis.The photosynthetic rate of the flag leaf at the middle and late grain filling stages underthe same N rate conditions was not significantly different in the SR and RS treatments, butthis rate was significantly higher in the SRS treatment. This photosynthetic rate in the Rtreatment was the lowest among all treatments. The SPS activity of the flag leaf at the middleand late grain filling stages in the SRS treatment was significantly higher than that in othertreatments, which was beneficial for sucrose synthesis. The SRS treatment had the highest drymatter accumulation at maturity

Mots clés : dryland wheat tillage nitrogen application rate nitrogen application depth water consumption characteristics grain yield

Présentation (Dissertation topics)

Page publiée le 8 octobre 2014, mise à jour le 10 janvier 2018