关键词: 冬小麦, 产量水平, 籽粒产量, 养分需求量, 干物质累积, 华北地区

Abstract:

【Objective】The objective of this study was to clarify the characteristics of N, P and K nutrient demand of high-yielding winter wheat and to identity the relationship between N, P and K requirements and grain yield, so the results of the study could provide theoretical basis and technical support for in-season nutrient management of high-yielding winter wheat in North China Plain. 【Method】 Under the optimal nitrogen, phosphorus and potassium fertilizer treatment, some databases of nutrient demand of winter wheat was created by collecting on-farm experiments in different places and in many years to evaluate the relationship between aboveground N, P and K uptake and grain yield to quantify N, P and K requirements per ton grain yield in North China Plain.【Result】For the optimal N fertilizer treatment, the average N requirement per ton grain in North China Plain was 24.3 kg and it declined with increasing grain yield. For the yield ranges between <4.5 t·hm^-2 and 6.0 to 7.5 t·hm^-2, the N requirement per ton grain decreased from 27.1 kg to 24.5 kg due to increasing harvest index and decreasing grain N concentration. For the yield ranges between 6.0 to 7.5 t·hm^-2 and 9.0 to 10.5 t·hm^-2, the N requirement per ton grain decreased from 24.5 kg to 22.7 kg due to decreasing grain N concentration. For the yield ranges >10.5 t·hm^-2, the N requirement per ton grain tended to be stable and changed little. Under the optimal P fertilizer treatment, the average P requirement per ton grain was 4.5 kg, and it declined from 4.7 kg in the yield range of <4.5 t·hm^-2 to 4.2 kg in the yield range of >9.0 t·hm^-2 due to the increasing harvest index and the diluting effect of declining grain P concentrations. Under the optimal K fertilizer treatment, the average K requirement per ton grain was 21.1 kg and it declined with increasing grain yield, it decreased from 23.8 kg with <4.5 t·hm^-2 to 20.2 kg with >7.5 t·hm^-2, which was attributed to the increase of the harvest index and decline in grain potassium concentrations. The largest variation in dry matter and nutrient accumulation occurred from the stem elongation stage to anthesis stage.【Conclusion】Under the optimal nitrogen, phosphorus and potassium fertilizer treatment in North China Plain, the N, P and K uptake requirement increased with increasing grain yield. The average N, P and K requirement per ton grain declined with increasing grain yield, which was attributed to the increase of the harvest index and decline in grain N, P and K concentrations. For different yield levels of winter wheat, there was higher dry matter accumulation rate and nutrient uptake rate after the stem elongation stage of high yield levels.

Key words: winter wheat, yield level, grain yield, nutrient requirement, dry matter accumulation, North China Plain