Section 67
Chapter 66,243

Effect of Long-Term Potassium Fertilization on Crop Yield and Potassium Efficiency and Balance Under Wheat-Maize Rotation in China

Zhang Hui-Min; Yang Xue-Yun; He Xin-Hua; Xu Ming-Gang; Huang Shao-Min; Liu Hua; Wang Bo-Ren

Pedosphere 21(2): 154-163


ISSN/ISBN: 1002-0160
DOI: 10.1016/s1002-0160(11)60113-6
Accession: 066242765

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Sustainable potassium (K) management at different soil sites requires understanding the relationships between crop productivity and long-term K fertilizations on a regional or national scale. We analyzed responses of grain yield of wheat (Triticum aestivum L.) and maize (Zea mays L.), K efficiency, and partial balance (difference between K input through fertilizer and K output in the aboveground biomass) during 15- (1990-2005) or 18-year (1990-2008) K fertilizations at five distinctive agroecological zones across China. Compared to the inorganic nitrogen (N) and phosphorus (P) fertilization, the inorganic NPK fertilization significantly increased grain yields of wheat (21%) and maize (16%-72%) at Qiyang and Changping, where soils have low exchangeable and non-exchangeable K contents, but not at Urumqi, Yangling and Zhengzhou, where soils have a high exchangeable and non-exchangeable K and/or low N/K ratio in crop plants. Compared to the inorganic NPK fertilization, the inorganic NPK (30% N) and organic manure (70% N) fertilization (NPKM) increased grain yields of wheat (14%-40%) and maize (9%-61%) at four sites, but not at Zhengzhou. For a productivity of wheat at 2-5 t ha(-1) or maize at 3-6 t ha(-1), 13-26 or 9-17 kg K ha(-1) were required to produce 1.0 t wheat or maize. The NP fertilization resulted in the lowest negative partial K balance and accumulated 52 kg K ha(-1) year(-1) less than the NPK fertilization, which accumulated 28 kg ha(-1) year(-1) less K than the NPKM fertilization. A re-evaluation of the site-specific fertilization effects on N/K ratio in crop plants and soil K accumulation under current NPK and NPKM fertilization is urgently needed to increase both crop yield and K use efficiency at different agroecological zones across China.

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