Study On Water And Nitrogen Use Characteristics Of Spring Wheat And Their Interrelation

Water use efficiency(WUE)and nutrient use efficiency(NUE)are two important indicators of plant resource utilization. The WUE and NUE of crop play an important role in drought adaptation, increasing agricultural production and income, reducing environment pollution, etc. The WUE and NUE of crop were influenced by many factors, including: soil moisture, soil nutrients, crop species, climate conditions and the measures of irrigation and fertilization. At present, species of the selection and cultivation and management of optimization was the main direction in improving the WUE and NUE of crop.In this paper, the interrelation between WUE and NUE was investigated by three types of resistance in spring wheat Heshangtou, DingXi35, NingChun4 under different level of water and nitrogen. the three water levels were: 80-85% of field capacity(Wg); 60-65% of field capacity(Wz); 40-45% of field capacity(Wd), the three nitrogen levels were: 0.25 g pure nitrogen /kg dry soil(Ng); 0.15g pure nitrogen /kg dry soil(Nz); 0.05g pure nitrogen /kg dry soil(Nd). There were totally five treatments combinations: NgWg, NzWz, NdWd, NdWg, NgWd, repeated three times.The main conclusions of the study are summarized as follows:1,More water and less nitrgon could improve the NUE of spring wheat. The WUE of spring was the highest under middle level of water and nitrgon. The WUE of HeShangTou was the highest, and the NUE of DingXi was the highest in three varieties spring wheat. There was a negatively relation between WUE and NUE, and wasnot related with levels of water and nitrgon;2,The malonaldehyde(MDA) contents of spring wheat significantly increased under drought stress. Drought and nitrogen caused activities of antioxidant defense enzymes(SOD,POD,CAT,APX)and the contents of antioxidants(ASA,GSH)of three sping wheat increased. The drought tolerance of HeShangTou was stronger than that of DingXi35 and NingChun4.3,Drought and nitrogen caused contents of praline(Pro),soluble protein and soluble suger of three sping wheat significantly increased. The osmotic adjustment ability of HeShangTou was the strongest, following by DingXi35. Soil moisture and nitrogen increased the activities of NR, the activities of NR in DingXi35 was stronger than that of HeShangTou and NingChun4.