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Accueil du site → Doctorat → Chine → 2010 → Effects Of Fertilization, Mulch And Tillage On Crop Yields And Soil Quality In The Semi-arid Loess Plateau Of China

China University (2010)

Effects Of Fertilization, Mulch And Tillage On Crop Yields And Soil Quality In The Semi-arid Loess Plateau Of China

Liu C A

Titre : Effects Of Fertilization, Mulch And Tillage On Crop Yields And Soil Quality In The Semi-arid Loess Plateau Of China

Auteur : C A Liu

Grade : Doctoral Dissertation 2010

Université : China University

Résumé partiel
Recently,a method using double ridges and furrows mulched with plastic film for micro-catchment water harvesting has been rapidly developing for maize owing to its significant effect on increased yields in dry-land farming system.Terraces have a significant effect of rainwater harvesting and soil conservation,so more and more terraces were used in the cultivation of maize with this technique.Terracing of sloping fields has been widely adopted by farmers in semiarid areas.This technique needs significant inputs of money and labor every year,and result in decrease of soil fertility and soil dryness in the deep soil profile.In 2003,one experiment was established to explore the optimum method for improving crop yields and soil fertility in newly built terraces ;in 2006,another experiment was established to minimize investment, improve economic benefits and overcome the problems of soil dryness in the deep soil profile and decrease of soil fertility.(1) August 2003 onwards:1) MNP,or sheep manure plus nitrogen and phosphorus,2) NP,or nitrogen and phosphorus but no manure,3) M,or manure alone,that is neither nitrogen nor phosphorus,and 4) CK,or control(check),that is neither fertilizers nor manure.The rotation of field pea(Pisum sativum L.),spring wheat(Triticum aestivum L.),and potato(Solanum tuberosum L.) was applied in newly built terraces.(2) In March 2003,three treatments were established under double ridges and furrows mulched with plastic film:1) plastic-film mulching at maize sowing with conventional tillage,and the film was removed at harvest(CK) ;2) mulching applied 30 d before sowing with conventional tillage,and the film was removed at harvest(T1) ;and 3) mulching at sowing with no tillage,and the film left on the field after harvest in the first season and used for mulching in the second season(T2).MNP improved soil water conversation,with the average soil water content in 0-100 cm soil depth over the 6 years increased 26.9mm before sowing date,compared to NP,the value between M and CK was 12.8 mm ;Manure treatments(MNP and M) were propitious to increase the soil water content in the 0-40 cm soil layer.Compared to CK,fertilization decreased the soil water content in the 100-200 cm soil layer throughout the duration of the experiment.Total rainfall storage in soil throughout the duration of the growing season for NP,CK,M and MNP were 207.7,217.9,269.7 and 291.8 mm in the 0-200 cm soil layer,respectively.Yields and water use efficiency (WUE) were the highest in MNP,and yields in MNP—as much as 70%of the corresponding yields in established terraces in the region in the case of field pea and spring wheat and 90%in the case of potato.Soil organic carbon(SOC) and soil total nitrogen(TN) built up faster in MNP and M than in CK or NP in the short term.C/N and C/P in MNP have been optimized,but the C/N in NP gradually left equilibrium point.From the third year,mineral nitrogen(MN) and available phosphorus(AP) were significantly higher in MNP than in other treatments

Mots clés : Maize, Newly-built terraces, Double ridges and furrows, Plastic film mulch, Soil water, Water use efficiency, Soil organic carbon, Soil microbial biomass carbon, Light fraction of organic carbon, Total nitrogen, soil microbial biomass nitrogen

Présentation (Globethesis)

Page publiée le 21 avril 2013, mise à jour le 4 mai 2018