Effects Of Different Tillage On Growth And Yield And Grain Protein Quality In Wheat In Soybean-wheat Rotation System

In order to find the mechanism of acquainting higher yield and quality underdifferent tillage in Yu xi dry rain-red areas, a field experiment using wheat cultivar,luohan6was carried out to study the effects of seven tillage treatments on farm weeds,accumulation and translocation of dry matter and nutrient, senescence characteristicsof flag leaves, grain yield and protein quality in wheat in soybean-wheat rotationsystem. The seven tillage treatments were as follows: conventional tillage (CT),conventional tillage with straw mulching (CTS), rotary tillage (RT), rotary tillage withstraw mulching (RTS), no-tillage with straw mulching (NTS), subsoiling tillage withstraw mulching in soybean and no-tillage with straw mulching in wheat (STS-NTS)and subsoiling tillage with straw mulching (STS). The main results were as follows.1. Descurainia sophia was the dominance weed in wheat fields. Compared toconventional tillage, the density of Descurainia sophia was reduced under theconventional tillage with straw mulching, rotary tillage and rotary tillage with strawmulching, but improved significantly under the subsoiling tillage with straw mulchingin soybean and no-tillage with straw mulching in wheat, no-tillage with strawmulching and subsoiling tillage with straw mulching. The density of Euphorbiahelioscopia was reduced under the rotary tillage and conservation tillage treatmentswith straw mulching. Conservation tillage treatments with straw mulching breed moreLagopsis spina and Galiam aparine, and improved species richness and weedsdiversity, but reduced weeds community dominance. The subsoiling tillage with strawmulching in soybean and no-tillage with straw mulching in wheat, no-tillage withstraw mulching and subsoiling tillage with straw mulching breed Capsella bursa-pastoris and Veronica polita pries, and Veronica polita pries was the dominantcommunities weed.2. Compared to conventional tillage, under the tillage treatments with strawmulching the accumulation amounts of dry matter in grains was increased by 2.95%~16.67%, translocation of dry matter in vegetative organs by24.36%~46.51%,translocation rate of dry matter in vegetative organs by3.12%~10.17%andcontribution rate of dry matter translocated to grains in vegetative organs by3.30%~15.31%. The results showed that conservation tillage treatments with strawmulching were beneficial to the translocation of dry matter in vegetative organs tograins. Under the tillage treatments with straw mulching the chlorophyll content andsoluble protein content of flag leaves were improved, and SOD activity and PODactivity of flag leaves were improved, and MDA content were reduced in the latefilling. The no-tillage with straw mulching and subsoiling tillage with straw mulchingwere the best treatments.3. Compared to conventional tillage, under the tillage treatments with strawmulching the accumulation amounts of nitrogen in grains was increased by3.41%~20.37%, accumulation of phosphorus by14.49%~31.83%and accumulation ofpotassium by5.57%~34.51%. Translocation of nitrogen in vegetative organs wasincreased by20.85%~70.59%, translocation of phosphorus by26.69%~53.99%andtranslocation of potassium by9.02%~39.29%. Translocation rate of nitrogen invegetative organs was increased by1.19%~12.99%, translocation rate of phosphorusby5.85%~8.00%and translocation rate of potassium by3.84%~8.08%. Contributionrate of nitrogen translocated to grains in vegetative organs was increased by4.31%~31.89%, contribution rate of phosphorus translocated to grains by3.02%~18.95%and contribution rate of potassium translocated to grains by11.15%~57.39%. The results showed that conservation tillage treatments with strawmulching were beneficial to the translocation of nitrogen, phosphorus and potassium invegetative organs to grains. The no-tillage with straw mulching and subsoiling tillagewith straw mulching were the best treatments.4. In this trail conditions, the amylopectin and total starch content in grains andamylopectin and amylose ratio were significantly improved under the rotary tillagewith straw mulching. There were some highly significantly positive correlationsbetween grain protein content including total protein content, globulin content, gliadincontent and most of processing quality parameters such as dough development time,dough stability time, extensible area, resistance to extensibility and extensibility, andsome significantly or highly significantly positive correlations were found betweenglutenin and most of processing quality parameters such as dough stability time,extensible area, resistance to extensibility and extension. Water absorption and degree of softening were significantly affected by gliadin content. Water absorption was thehighest and degree of softening was the lowest under the subsoiling tillage with strawmulching. The grain gliadin content was reduced under the rotary tillage and rotarytillage with straw mulching. The grain globulin content and gliadin content wereimproved under the conventional tillage with straw mulching. The grain proteincontent and its components including globulin content and gliadin content wereimproved under the subsoiling tillage with straw mulching in soybean and no-tillagewith straw mulching in wheat, and significantly improved under the no-tillage withstraw mulching and subsoiling tillage with straw mulching. The quality parameterssuch as farinograph quality number, dough development time, dough stability time,extensible area, resistance to extensibility, maximum resistance to extensibility andextension were improved under the subsoiling tillage with straw mulching in soybeanand no-tillage with straw mulching in wheat, and significantly improved under the no-tillage with straw mulching and subsoiling tillage with straw mulching.5. Compared to conventional tillage, the conservation tillage managements almostpresented higher grain yield and the1000-grain weight which were significantlyimproved under the rotary tillage with straw mulching, no-tillage with straw mulching,subsoiling tillage with straw mulching in soybean and no-tillage with straw mulchingin wheat and subsoiling tillage with straw mulching, and the grain yield in winterwheat increased by10.67%,2.41%,7.34%and23.17%, respectively. Rotary tillagepresented lower grain yield and the1000-grain weight which was significantly reduced,and the grain yield in winter wheat reduced by1.71%.