Effects Of Irrigation And Fertilization On Water And Nitrogen Use Of Intensive Wheat-maize Double Cropping System

The experiment was conducted in an intensive wheat-maize double cropping system inHuang-Huai-Hai Plain of China. Two winter wheat varieties (SM15and JM19) and two summer maizevarieties (ZN99and LN14) were chosen to study the water and nitrogen use of different wheat/maizevarieties under different fertilizer types (Inorgnic fertilizer, orgnic fertilizer, orgnic and inorganiccombined fertilizer), different fertilizer input levels and different irrigation ragimes.The main results arebelow:(1) There was no significant difference in the yield of SM15under inorganic fertilizer treatment,but the yield of JM19increased with the increasing fertilizer input levels under inorganic fertilizertype.And the yields of SM15and JM19under orgnic fertilizer and orgnic combined with inorganicfertilizer also increased with the increasing fertilizer input levels. Under the same fertilizer input level,wheat yield of orgnic fertilization treatments is significantly lower than the other two fertilizer types. In180kg N/ha fertilizer input level,the yield under orgnic combined with inorganic fertilizer was lowerthan inorganic fertilizer level,but in240kg N/ha fertilizer input level,there was no significantdifferences between orgnic combined with inorganic fertilizer and inorganic fertilizer treatment. Therewas no significant differences in wheat yields under different irrigation ragimes (270mm,180mm and90mm),but the yield was highest under180mm irrigation ragimes. Changes of wheat crude proteincontents under different irrigation and fertilizer treatments were similar to the yields changes. As todifferent genotype varieties, the flour sedimentation value of JM19was significantly higher than that ofSM15, and showed significantly differences among different treatments.The Wet gluten content of intwo varieties is no significant difference,both of them are the lowest under organic fertilizer treatments;the stability property of dough of JM19is longer than SM15.(2) The average yield was highest under organic combined with inorganic fertilizer inputtreatments, and generally decreased with the increasing fertilizer input levels except of the LN14yieldin orgnic fertilizer input treatments. Yields of LN14in inorganic fertilization treatments and in orgniccombined with inorganic fertilization treatments were obviously lower than ZN99, but in organicfertilization treatments the yields of ZN99were higher than that of LN14. The crude protein content andlysine content of maize in orgnic fertilization treatments were significantly lower than those in otherfertilizer types input treatments. And the crude protein content generally increased with the increasingfertilizer input levels, but there was no difference with the lysine contents among these treatments. Theaverage content of crude starch in organic fertilization treatments is the highest, and is the lowest under240kgN/ha inorganic fertilizer input treatment.(3) The wheat nitrogen uptake under180mm irrigation regime is the highest among irrigationtreatments, but there were no obvious differences in them. Both of wheat and maize nitrogen uptakeswere lower in organic fertilization treatments than in other two fertilizer input types treatments. The wheat nitrogen uptakes increased with the increasing fertilizer input levels,while the maize nitrogenuptakes showed the opposite trend. The nitrogen physiological use efficiency of wheat and maizeshowed significant differences among different fertilizer input types treatments, and the trend isoganic fertilization treatment>oganic+inorganic fertilization treatment>inorganic fertilization treatment.As to different wheat varieties, the nitrogen uptake of JM19is higher than that of SM15, but there wereno significant differences between them. For maize varieties, the average nitogen uptake of LN14wassignificantly higher than that of ZN99under organic fertilization treatments, but it showed the oppositetrend under the other two fertilizer input types treatments.(4) During wheat flowering stage, the nitrate nitrogen contents of0-100cm soil profiles decreasedwith the increasing irrigation amount, while after wheat harvest, the nitrate nitrogen contents of0-100cm soil profiles showed no significant differences with the increasing irrigation amount. Theaverage nitrate nitrogen content of2m soil profiles was the lowest under270mm irrigation regime,which shows270mm water promoted soil nitate leaching losses.The nitrate nitrogen contents of soilprofiles under organic fertilization treatments were lower than under inorganic fertilization treatmentsand organic-inorganic fertilization treatments. The nitrate nitrogen contents of0-100cm soil profilesafter harvest under240kgN/ha fertilizer input treatment is higher than under180kgN/ha fertilizer inputtreatment, which showed that the increasing fertilizer input levels could improve nirate nitrogen contentin soil after harvest. The Nep%under270mm irrigation treatment was the highest in the three irrigationragimes,and the Nep%under90mm irrigation treatment was the lowest.The trend of Nep%underdifferent fertilizer types was orgnic fertilization treatment>orgnic and inorganic combined fertilizationtreatment>inorganic fertilization treatment.The Nep%increased with the ircreasing fertilizer inputlevels. In different varieties, the nitrate nitrogen content of JM19in2m soil profiles was higher than thatof SM15.(5) Soil water content after wheat harvest increased with the increasing irrigation amounts; thehigher irrigation water input, the lower water use efficiency. When the irrigation water was270mm,water use efficiency of wheat under inorganic fertilization treatments and orgnic-inorgatic fertilizationtreatments increased with the increasing fertilizer input levels; But when the irrigation water was180mm and90mm, water use efficiency of wheat under inorganic fertilization treatments decreasedwith the increasing fertilizer input levels, and increased with the increasing fertilizer input levels underorgnic-inorgatic fertilization treatments.Water use efficiency of wheat under organic fertilizationtreatments is the lowest in the three fertilizer input types treatments.For maize, the water use efficiencywas significantly different among different treatments. As to different genotype varieties, the water useefficiency of ZN99was significantly higher than that of LN14. The water use efficiency of ZN99underinorganic fertilization treatments and organic-inorganic fertilization treatments was higher than that ofLN14seperately,but was lower than that of LN14under organic fertilization treatments.