麦秸全量还田下水稻物质生产与分配对氮肥运筹的响应.

[Objective] This paper studies the optimal rice nitrogen fertilizer management measures under the condition of returning the whole wheat straw to the field, in order to provide a theoretical basis for the utilization of straw returning to the field and the reduction of high-efficiency nitrogen application. [Method] The soil culture experiment was adopted, and the nitrogen application rate was set as constant nitrogen application (A1, 270 kg/hm²) and reduced nitrogen application (A2, 240 kg/hm²). Nitrogen management was used to set a high-ratio basal nitrogen fertilizer (B1, basal fertilizer: tiller Fertilizer: ear fertilizer = 5: 2: 3) and high-ratio tiller nitrogen fertilizer (B2, base fertilizer: tiller fertilizer: ear fertilizer = 2: 5: 3), with no nitrogen (CK, 0 kg/hm²) as the control, The characteristics of plant height, dry matter accumulation and distribution of different nitrogen levels and nitrogen management in key growth stages of rice were systematically compared. [Result] Under the condition of returning all wheat straw to the field, the plant height of rice in the late stage of the reduced nitrogen application was significantly lower than that of the constant nitrogen application, and the plant height increased under the two nitrogen application rates to increase the ratio of tiller nitrogen fertilizer (2∶5∶3). high. From booting stage to maturity stage, the dry matter quality of the aboveground rice in the treatment of reduced nitrogen application was lower than that of the treatment of constant nitrogen application. From the heading stage to the maturity stage, the rice leaf biomass and its proportion to the total biomass of the reduced nitrogen application were lower than that of the constant nitrogen application, and the proportion of the leaves under the high-ratio tiller nitrogen fertilizer treatment under the two nitrogen application rates was higher; The stalk biomass of the reduced nitrogen fertilization treatment was lower than that of the constant nitrogen fertilization, and the ratio of the tiller nitrogen fertilizer ratio was increased under the two nitrogen fertilization rates. The stalk biomass proportion of the stalk biomass was reduced; the reduced nitrogen fertilization treatment had a constant leaf sheath biomass and distribution Nitrogen application decreased, and the difference in leaf sheath biomass at heading stage reached a significant level; ear biomass and its proportion were higher than that of constant nitrogen application under reduced nitrogen application, and the ratio of tiller nitrogen fertilizer increased under reduced nitrogen application. The amount is reduced. [Conclusion] It can be seen from the above that under the condition of fully returning wheat straw to the field, high plant height and above-ground dry matter quality can be obtained in the middle and late stages of rice under constant nitrogen application, and the biomass and distribution ratio of leaves, stems and leaf sheaths are generally increased. Under constant nitrogen application, increasing the ratio of tiller nitrogen fertilizer is beneficial to the material production and accumulation of rice vegetative organs, while reduced nitrogen application is beneficial to the material accumulation and distribution of rice panicles. [ABSTRACT FROM AUTHOR]