长期有机无机配施黑土土壤有机碳对农田基础地力提升的影响

【目的】探讨长期不同施肥方式对提升东北黑土土壤有机碳和农田基础地力的差异。【方法】以国家黑土肥力和肥料效益长期监测试验(1989—2011年)资料为基础,采用DSSAT ver.4.0作物生长模型模拟:(1)CK(对照,不施肥);(2)NPK(施氮磷钾肥);(3)NPKM(有机肥+NPK化肥,M指有机肥);(4)l.5NPKM(NPKM处理的1.5倍);(5)NPKS(秸秆+NPK化肥,S指玉米秸秆)5种施肥方式下东北黑土区春玉米20年的农田基础地力产量,在分析长期不同施肥措施下基础地力与土壤有机碳的演变规律的基础上,进一步探讨两者之间的数量化关系。【结果】经过20年施肥管理,NPK、NPKM、1.5NPKM和NPKS施肥处理春玉米农田基础地力产量分别增长了53.4%、78.0%、101.2%和69.4%,而CK处理的基础地力产量随时间延长呈下降趋势。到2008年,1.5NPKM、NPKM、NPKS、NPK 4个处理的土壤有机碳含量分别比CK处理的土壤有机碳含量增加了65.6%、65.1%、26.0%和21.7%,土壤有机碳储量分别提升了69.9%、44.2%、25.2%和16.7%。土壤有机碳含量与春玉米基础地力产量呈显著正相关(P0.01),土壤有机碳含量每增加1 g·kg-1,春玉米农田基础地力产量大约提高220 kg·hm-2。【结论】土壤有机碳是黑土区基础地力的主要驱动因素,有机肥或秸秆与化肥配施提升了土壤有机碳,因而能有效提高春玉米农田基础地力产量和基础地力贡献率。增加有机物料投入是黑土区农田基础地力培育的最佳施肥措施。

Effects of Long-Term Organic and Inorganic Fertilization on Enhancing Soil Organic Carbon and Basic Soil Productivity in Black Soil

【Objective】The objective of this study is to explore the effects of different long-term fertilizations on soil organic carbon (SOC) and basic soil productivity (BSP) in the northeast area of China. 【Method】Based on the data of the long-term experiments (1989-2011) on black soil in Gongzhulin, Jilin Province, China, the decision support system for an agrotechnology transfer crop growth model (DSSAT ver.4.0) was used to simulate yields by basic soil productivity of spring maize (Zea mays L.) to examine the relationship between BSP and SOC under long-term fertilization. Five treatments were included: (1) no-fertilization (Control), (2) synthetic fertilizer N, P, K (NPK), (3) NPK plus farmyard manure (NPKM), (4) 1.5 times of NPKM (1.5NPKM) and (5) NPK plus straw (NPKS). 【Result】After 20 years of treatments, the yields of BSP of spring maize increased 53.4%, 78.0%, 101.2%, and 69.4% under the NPK, NPKM, 1.5NPKM and NPKS, respectively, but the yield decreased under the CK. Until 2008, the SOC content increased 65.6%, 65.1%, 26.0%, and 21.7% under the 1.5NPKM, NPKM, NPKS and NPK, respectively, compared to the CK. The SOC stock increased 69.9%, 44.2%, 25.2%, and 16.7% compared to the initial value. There were significant positive correlations between SOC content and yields by BSP of spring maize (P＜0.01), and yields by BSP of spring maize increased 220 kg·hm^-2 when the SOC content increased 1 g?kg^-1.【Conclusion】SOC was a major factor affecting BSP in the black soil. The manure or straw combined application with chemical fertilizers significantly enhanced BSP compared to the application of chemical fertilizers alone.