CAJ | 학술논문

【目的】研究不同稻作区域钾肥和秸秆还田对水稻产量、钾素吸收量以及农田钾素表观平衡的影响，分析不同稻区秸秆还田可替代化学钾肥的用量，为不同区域稻田秸秆还田条件下钾肥的合理配置提供理论依据。【方法】2013年在湖北省鄂东丘陵、鄂中丘陵岗地和江汉平原3个区域的19个县（市）布置稻田秸秆还田替代钾肥效果研究田间试验，试验共设置6个处理：分别为（1）不施钾（NP）；（2）施化学钾肥（NPK）；（3）施秸秆（NP+S）；（4）秸秆还田配施1/2化学钾肥（NP+1/2K+S）；（5）秸秆还田配施3/4化学钾肥（NP+3/4K+S）；（6）秸秆还田配施全量化学钾肥（NPK+S）。【结果】不同稻作区钾肥和秸秆均能不同程度增加水稻产量和地上部钾素吸收量。与NP处理相比，鄂东丘陵区、鄂中丘陵岗地区和江汉平原区NPK处理水稻分别增产0.36、0.36和1.07 t·hm-2，平均增产率分别为6.4%、5.0%和15.3%；而施秸秆（NP+S）处理水稻分别平均增产0.57、0.49和0.24 t·hm-2，增产率为7.6%、6.9%和4.0%。3个稻作区施化学钾肥（NPK）地上部钾素吸收量平均增加20.1—61.9 kg K2O·hm-2，施秸秆（NP+S）钾素吸收量平均增加8.5—39.1 kg K2O·hm-2，江汉平原区施化学钾肥处理产量和钾素吸收量均显著高于施秸秆处理，而鄂东丘陵区和鄂中丘陵岗地区NP+S与NPK处理的产量和钾素吸收量均没未表现出差异。通过计算土壤-作物系统钾素表观平衡，发现一季水稻收获后土壤钾素均处于亏缺（平均钾素亏缺量为144.3—284.4 kg K2O·hm-2）状态，但秸秆还田处理亏缺量小于秸秆不还田处理。在保证水稻产量（即NPK处理产量）时秸秆还田条件下，采用模型计算出鄂东丘陵区、鄂中丘陵岗地区和江汉平原区的平均钾肥用量分别比目前钾肥推荐用量（60 kg K2O·hm-2）节约化学钾肥66.8%、75.2%和9.7%；参考2013年钾肥和水稻价格，可计算出秸秆还田条件下鄂东丘陵区、鄂中丘陵岗地区和江汉平原区最经济钾肥推荐用量分别比推荐用量节省化学钾肥54.3%、53.5%和36.9%。【结论】湖北省不同稻区均可采用秸秆还田的方式减少钾肥投入，不但可以缓解土壤钾素亏缺，而且对农田钾素的可持续管理具有重要意义。【目的】研究不同稻作區域鉀肥和秸稈還田對水稻產量、鉀素吸收量以及農田鉀素錶觀平衡的影響，分析不同稻區秸稈還田可替代化學鉀肥的用量，為不同區域稻田秸稈還田條件下鉀肥的閤理配置提供理論依據。【方法】2013年在湖北省鄂東丘陵、鄂中丘陵崗地和江漢平原3箇區域的19箇縣（市）佈置稻田秸稈還田替代鉀肥效果研究田間試驗，試驗共設置6箇處理：分彆為（1）不施鉀（NP）；（2）施化學鉀肥（NPK）；（3）施秸稈（NP+S）；（4）秸稈還田配施1/2化學鉀肥（NP+1/2K+S）；（5）秸稈還田配施3/4化學鉀肥（NP+3/4K+S）；（6）秸稈還田配施全量化學鉀肥（NPK+S）。【結果】不同稻作區鉀肥和秸稈均能不同程度增加水稻產量和地上部鉀素吸收量。與NP處理相比，鄂東丘陵區、鄂中丘陵崗地區和江漢平原區NPK處理水稻分彆增產0.36、0.36和1.07 t·hm-2，平均增產率分彆為6.4%、5.0%和15.3%；而施秸稈（NP+S）處理水稻分彆平均增產0.57、0.49和0.24 t·hm-2，增產率為7.6%、6.9%和4.0%。3箇稻作區施化學鉀肥（NPK）地上部鉀素吸收量平均增加20.1—61.9 kg K2O·hm-2，施秸稈（NP+S）鉀素吸收量平均增加8.5—39.1 kg K2O·hm-2，江漢平原區施化學鉀肥處理產量和鉀素吸收量均顯著高于施秸稈處理，而鄂東丘陵區和鄂中丘陵崗地區NP+S與NPK處理的產量和鉀素吸收量均沒未錶現齣差異。通過計算土壤-作物繫統鉀素錶觀平衡，髮現一季水稻收穫後土壤鉀素均處于虧缺（平均鉀素虧缺量為144.3—284.4 kg K2O·hm-2）狀態，但秸稈還田處理虧缺量小于秸稈不還田處理。在保證水稻產量（即NPK處理產量）時秸稈還田條件下，採用模型計算齣鄂東丘陵區、鄂中丘陵崗地區和江漢平原區的平均鉀肥用量分彆比目前鉀肥推薦用量（60 kg K2O·hm-2）節約化學鉀肥66.8%、75.2%和9.7%；參攷2013年鉀肥和水稻價格，可計算齣秸稈還田條件下鄂東丘陵區、鄂中丘陵崗地區和江漢平原區最經濟鉀肥推薦用量分彆比推薦用量節省化學鉀肥54.3%、53.5%和36.9%。【結論】湖北省不同稻區均可採用秸稈還田的方式減少鉀肥投入，不但可以緩解土壤鉀素虧缺，而且對農田鉀素的可持續管理具有重要意義。
【목적】연구불동도작구역갑비화갈간환전대수도산량、갑소흡수량이급농전갑소표관평형적영향，분석불동도구갈간환전가체대화학갑비적용량，위불동구역도전갈간환전조건하갑비적합리배치제공이론의거。【방법】2013년재호북성악동구릉、악중구릉강지화강한평원3개구역적19개현（시）포치도전갈간환전체대갑비효과연구전간시험，시험공설치6개처리：분별위（1）불시갑（NP）；（2）시화학갑비（NPK）；（3）시갈간（NP+S）；（4）갈간환전배시1/2화학갑비（NP+1/2K+S）；（5）갈간환전배시3/4화학갑비（NP+3/4K+S）；（6）갈간환전배시전양화학갑비（NPK+S）。【결과】불동도작구갑비화갈간균능불동정도증가수도산량화지상부갑소흡수량。여NP처리상비，악동구릉구、악중구릉강지구화강한평원구NPK처리수도분별증산0.36、0.36화1.07 t·hm-2，평균증산솔분별위6.4%、5.0%화15.3%；이시갈간（NP+S）처리수도분별평균증산0.57、0.49화0.24 t·hm-2，증산솔위7.6%、6.9%화4.0%。3개도작구시화학갑비（NPK）지상부갑소흡수량평균증가20.1—61.9 kg K2O·hm-2，시갈간（NP+S）갑소흡수량평균증가8.5—39.1 kg K2O·hm-2，강한평원구시화학갑비처리산량화갑소흡수량균현저고우시갈간처리，이악동구릉구화악중구릉강지구NP+S여NPK처리적산량화갑소흡수량균몰미표현출차이。통과계산토양-작물계통갑소표관평형，발현일계수도수획후토양갑소균처우우결（평균갑소우결량위144.3—284.4 kg K2O·hm-2）상태，단갈간환전처리우결량소우갈간불환전처리。재보증수도산량（즉NPK처리산량）시갈간환전조건하，채용모형계산출악동구릉구、악중구릉강지구화강한평원구적평균갑비용량분별비목전갑비추천용량（60 kg K2O·hm-2）절약화학갑비66.8%、75.2%화9.7%；삼고2013년갑비화수도개격，가계산출갈간환전조건하악동구릉구、악중구릉강지구화강한평원구최경제갑비추천용량분별비추천용량절성화학갑비54.3%、53.5%화36.9%。【결론】호북성불동도구균가채용갈간환전적방식감소갑비투입，불단가이완해토양갑소우결，이차대농전갑소적가지속관리구유중요의의。
[Objective]The experiment was conducted to study the effects of potassium (K) fertilization and straw incorporation on rice yield, K uptake and K balance in different rice producing regions of Hubei province, in order to find how much chemical potassium can be replaced by straw potassium. The results would provide a scientific basis for K fertilization management under straw incorporation for different regions. [Method]Field trials in 19 counties were carried out to study the effects of the substitution of straw incorporation for K fertilization in hilly regions of east (HEH) and center Hubei (HCH) and Jianghan Plain (JHP) in 2013. The designed six treatments were no K fertilization (NP), chemical K fertilization (NPK), straw incorporation (NP+S), straw incorporation with 50%of chemical K fertilizer (NP+1/2K+S), straw incorporation with 75%of chemical K fertilizer (NP+3/4K+S), and straw incorporation with 100% of chemical K fertilizer (NPK+S). [Result]Both K fertilization and straw incorporation improved the rice yield and K uptake across the regions. Compared with NP treatment, the averaged rice yield increased by 0.36, 0.36 and 1.07 t·hm-2 in NPK treatment in the regions of HEH, HCH, and JHP, respectively, with the increasing rate of 6.4%, 5.0%and 15.3%. For the NP+S treatment, rice yield increased by 0.57, 0.49 and 0.24 t·hm-2 in HEH, HCH, and JHP regions, with the increasing rate of 7.6%, 6.9%and 4.0%, respectively. K fertilization (NPK) enhanced the K uptake by 20.1-61.9 kg K2O·hm-2, while the straw incorporation (NP+S) increased K uptake by 8.5-39.1 kg K2O·hm-2. Both yield and K uptake of NPK treatment were higher significantly than NP+S treatment in JHP area. However, no difference was observed between the NPK and NP+S treatments in the HEH and HCH areas. After calculating the apparent K balance, it was found that K lost (144.3-284.4 kg K2O·hm-2) occurred in all the treatments across the sites especially in the treatments without straw incorporation. Model was used to fit the relationship between K fertilization rate and rice yield, the optimum application rate of K fertilizer under straw incorporation for which could reach the yield under NPK treatment was obtained. The optimal K rate was 19.9, 14.9 and 54.2 kg K2O·hm-2 in the regions of HEH, HCH, and JHP, which saved chemical K fertilizer by 66.8%, 75.2% and 9.7% compared with the recommended amount (60 kg K2O·hm-2), respectively. Using the price of K fertilizer and rice in 2013, the economic optimum K rate (EOKR) could be obtained. The EOKR values were 27.4, 27.9 and 37.9 kg K2O·hm-2 in the HEH, HCH, and JHP, saved 54.3%, 53.5%and 36.9%chemical K fertilizer compared with the recommended amount, respectively. [Conclusion]Chemical K fertilizer could be partly replaced by straw incorporation across different rice planting regions in Hubei province. In addition, straw incorporation can alleviate soil K loss, which plays an important role in sustainable potassium management on farmland.