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Soil available potassium affected by rice straw incorporation and potassium fertilizer application under a rice–oilseed rape rotation system
Author(s) -
Zhu Dandan,
Zhang Jianglin,
Wang Zheng,
Muhammad Rizwan Khan,
Lu Jianwei,
Li Xiaokun
Publication year - 2019
Publication title -
soil use and management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.709
H-Index - 81
eISSN - 1475-2743
pISSN - 0266-0032
DOI - 10.1111/sum.12507
Subject(s) - straw , fertilizer , potassium , agronomy , rotation system , soil water , potash , soil test , chemistry , environmental science , zoology , mathematics , nitrogen , soil science , biology , organic chemistry
Data from 147 field trials were collected to study the influence of straw incorporation on soil potassium (K) under an intensive rice–oilseed rape rotation system, while pot experiments were conducted to evaluate the effects of rice straw incorporation on soil K availability. A significant correlation was observed between the soil available K and the relative yield ( RRY ) and the relative K uptake ( RKU ) of oilseed rape, with R 2 values ranging from 0.07 to 0.08 and from 0.10 to 0.11, respectively, when data were fitted to a logarithmic equation model. In approximately 30% of trials, RRY reached 90%, while soil test available K values were below the critical limit, indicating that soil K values at the time of sampling (within 1 week of rice harvest) underestimated the actual soil K supply capacity. The pot experiment results showed that soil available K was affected by straw incorporation and soil type in the fallow period. The NH 4 OA c‐K and Na BP h 4 ‐K concentrations of soils increased at first, and then, plateaued after 28 days. Straw incorporation significantly influenced the critical soil K concentration, which is important for making accurate K fertilizer recommendation. These results suggested that straw K should be seriously considered in making K fertilizer recommendations. Extending the sampling time from 1 to 3 weeks after the harvesting of rice to stabilize the effects of straw incorporation may help achieve a more accurate evaluation of soil available K.