长期不同养分投入对土壤养分和水稻生产持续性的影响

以中国科学院桃源农业生态试验站15a长期田间定位试验为研究对象,分析了不同养分投入对稻田土壤养分和水稻产量可持续性的影响.结果表明,化肥与系统内循环的有机物料循环的肥力效力和产量效应基本一致,有机物料循环更有利于土壤有机质和氮素的积累;在不同养分投入下,土壤耕层有机质和全氮均呈上升趋势,年均增长率分别为1.5%～5.8%和2.5%～9.4%;与试验前相比,不同养分投入耕层磷素变动幅度在-18.3%到30%之间,钾素养分有所亏缺,下降幅度在8.1%～22.6%之间;通过可持续性指数的分析得出,土壤N素养分的可持续性对化肥的依赖性较大,而P、K养分的可持续性则对有机肥的依赖性更高.稻田生态系统具有良好的自维持能力,系统内有机物循环有利于提高稻谷产量的稳定性和可持续性.

Effect of different fertilizer applications on sustainable soil fertility and rice production in red soil paddy ecosystem

Based on a long-term field experiment started in 1990 in Taoyuan Experimental Station of Agriculture Ecosystem-CERN, the effects of fertilization on the fertility and productivity of paddy soil were analyzed, so as to discuss the sustainability of ecosystem of double-cropped paddy field in subtropical red earth region. Results showed that: chemical fertilizer input and recycling of organic matter in the ecosystem had the similar effects on soil fertility and system productivity. Organic matter recycling was better for the accumulation of soil organic matter (SOM) and total nitrogen (N). SOM and total N under different nutrient inputs presented an assurgent direction in cultivated soil layer (0-20cm) and annual amplitude varied from 1.5%-5.8% and 2.5%-9.4%, respectively. Contrast to previous experiment, nutrient phosphorus (P) content in soil cultivated layer under fertilization regime varied from -18.3% to 30%, potassium (K) was exhausting which decreased from 8.1% to 22.6%. The sustainability index indicated that, the sustainability of soil N was much more dependent on chemical fertilizer input, while P and K were relied on organic fertilizer. Paddy ecosystem has a strong ability of self-maintenance and the recycling of organic matter within the ecosystem could be benefit to the stability and sustainability of the system.