Effect of fertilizer and green manure incorporation methods on the growth and water use efficiency of winter wheat

An experiment was carried out to investigate the effect of different fertilizer on green manure biomass in summer fallow period and the growth of next winter wheat.The fertilizer treatments included CK(no fertilizer),P(phosphate fertilizer,40 kg P2O5/hm2) and SF(special fertilizer for leguminous green manure crops,30 kg/hm2).The Effects of different methods of green manure incorporation on winter wheat yield and water production efficiency were also investigated.Green manure incorporation treatments included early incorporation(green manure was incorporated into soil half month before wheat sowing),early mulching(green manure crop was cut and left on the soil surface half month before wheat sowing,then incorporated into soil before wheat sowing),late incorporation (green manure was incorporated into soil before wheat sowing) and summer fallow (no green manure).The results showed that SF had significant higher aboveground biomass of green manure while SF had no effect on root biomass of green manure crop,compared with CK.P could increase root biomass of green manure crop.SF and P treatments obtained greater wheat yield,especially when green manure was incorporated into soil half month before wheat sowing.Early incorporation treatment had greater winter wheat tiller number,total shoot number,spike number and significantly higher wheat yield,compared with other treatments.Early incorporation treatment also increased water use efficiency of wheat compared with summer fallow.Soil water content differences through 0～200 cm profile between summer fallow and other three treatments were found from the date of green manure incorporation half month before wheat sowing to wheat jointing stage.There was obvious difference of soil water content above 40 cm depth among early incorporation,early mulch and late incorporation treatments.