中国主要麦区农户小麦氮磷钾养分需求与产量的关系

【目的】明确实际生产中农户小麦产量与养分需求的关系,为科学施肥、合理减肥提供理论依据。【方法】连续两年对中国小麦主产区多点的农户调研和取样分析,研究中国春麦、旱作、麦玉和稻麦4个典型种植区域农户小麦氮磷钾养分需求量与产量的关系。【结果】中国农户小麦产量平均为6.4 t·hm-2,麦区间存在显著的产量差异,春麦、旱作、麦玉和稻麦区平均分别为6.0、4.0、7.7和5.5 t·hm~(-2),产量越高的麦区小麦生物量越大、公顷穗数越多,收获指数随产量增加而增加。全国农户小麦平均需氮量为28.1 kg·Mg~(-1),4个麦区分别为28.6、28.3、29.3和25.0 kg·Mg~(-1),产量由低产增至高产时,旱作区和麦玉区小麦需氮量分别显著降低16.9%和14.6%,春麦和稻麦区有降低趋势,但未达差异显著水平。全国小麦平均需磷量为4.0 kg·Mg~(-1),4个麦区分别为4.5、3.2、4.1和4.1 kg·Mg~(-1),产量从低产增至高产时,麦玉和稻麦区分别显著降低11.4%、17.8%,旱作区需磷量降低8.6%,差异亦未达显著水平,春麦区低产时需磷量最低为3.7 kg·Mg~(-1),产量从偏低提高到高产水平时也显著降低21.4%。农户小麦平均需钾量为21.5 kg·Mg~(-1),各麦区存在显著差异,4个麦区分别为26.5、17.1、23.3和18.8 kg·Mg~(-1),产量由低产增至高产时,4个麦区需钾量分别降低4.0%、4.4%、12.7%和19.9%,仅稻麦区差异显著。【结论】中国各麦区农户的小麦产量存在显著差异,养分需求量与产量的关系因麦区而异,总体来看,随产量增加,小麦氮、磷、钾养分需求量呈降低趋势。可见,在向农户推荐肥料用量时,需针对不同区域,结合农户田块的小麦产量水平、作物养分需求特性和土壤养分供应能力,确定合理的养分需求量,避免肥料施用过量或不足。

Relationships of N,P and K Requirement to Wheat Grain Yield of Farmers in Major Wheat Production Regions of China

【Objective】It is of great significance to clarify relationships of NPK requirement to farmers’ wheat grain yield for reasonable fertilization and decreasing fertilizer application rates.【Method】A 2 years long on-farm survey combined with sample collection and analysis related to wheat production were carried out in the Spring Wheat (SW), Dryland Wheat (DW), Wheat-Maize (WM), Rice-Wheat regions (RW) of China, to study the relationships of NPK requirement to wheat grain yield of farmers.【Result】The mean grain yield of wheat was observed to be 6.4 t·hm^-2, and the differences were significant among the yield averages of different regions, with the grain yield average of 6.0, 4.0, 7.7, 5.5 t·hm^-2 in SW, DW, WM and RW region, respectively. The high yield regions usually had higher above-ground biomass and spike numbers, and harvest indexes increased with grain yields. The average N requirement was 28.1 kg·Mg^-1, with the average of 28.6, 28.3, 29.3 and 25.0 kg·Mg^-1 in SW, DW, WM and RW region, respectively, and the N requirement average decreased significantly by16.9% and 16.4% in DW and WM, tending to decrease but being not significant in SW and RW regions, when the yield was increased from the very low to the very high levels. The average P requirement was 4.0 kg·Mg^-1, with the average of 4.5, 3.2, 4.1 and 4.1 kg·Mg^-1 in SW, DW, WM and RW region, respectively. P requirement average decreased significantly by 11.4% and 17.8% in WM and RW, decreased by 8.6% but not significantin DW region, when the yield was increased from the very low to the very high levels, and even though the lowest P requirement of 3.7 kg·Mg^-1 occurred at the very low wheat yield level, it was still significantly decreased by 21.4%, when the yield was increased from the lower to the very high level. The average K requirement was 21.5 kg·Mg^-1, with the average of 26.5, 17.1, 23.3 and 18.8 kg·Mg^-1 respectively and significantly different in the four regions, and the K requirement average significantly decreased by 4.0%, 4.4%, 12.7% and 19.9% in SW, DW, WM and RW region, respectively, when the yield was increased from the very low to the very high levels, although the difference was only significant in the RW region. 【Conclusion】Wheat grain yield of farmers were significantly different among the main wheat production regions in China, relationships of NPK requirements to grain yields were also different with regions, and generally they tended to decrease with the grain yield increase. Therefore, fertilizer application recommendation should determine the reasonable nutrient requirement based on the yield levels, the crop nutrient requirement characteristics and the land soil nutrient supply capacities of farmers, in order to avoid over or insufficient fertilizer application in different regions of China.