稻田系统生产力及其稳定性对施肥制度的响应

Response of rice-rice ecosystem productivity and yield stability to long-term fertilization

为探讨长期不同施肥制度对稻田系统生产力及其稳定性的影响,以国家生态系统研究网络中国科学院桃源农业生态试验站稻田施肥试验（2004—2010年）监测数据为基础,分析不同施肥制度下红壤性稻田系统生产力及其稳定性。结果表明,施肥是维持和提升稻田系统生产力的物质基础,稻田系统生产力稳定性对不同施肥制度响应不同：（1）各施肥处理总生物量生产力显著高于不施肥处理,是不施肥处理的1.33~2.23倍,从高至低依次为：优化施肥处理〉常规施肥处理〉化肥处理〉不施肥处理,且优化施肥能显著提高总生物量生产力的稳定性（P〈0.05）;（2）各施肥处理的水稻产量均显著高于不施肥处理,是不施肥处理的1.35~2.02倍,年际变异系数分别为：不施肥处理22.4%、化肥处理15.8%、优化施肥处理10.3%、常规施肥处理15.7%,优化施肥处理产量稳定性最高;（3）地下部分生产力施肥处理显著高于不施肥处理,施肥年限较长的处理地下部分生物量生产力的稳定性显著高于年限较短的施肥处理（P〈0.05）。总的来说,优化施肥处理水稻生产力及其稳定性较好,不施肥处理水稻生产力及其稳定性最差;地上部分生产力及其稳定性和地下部分生产力受施肥制度的影响较大,而地下部分生产力的稳定性则受施肥年限影响较大。

The productivity and yield stability of rice-rice ecosystem in Huazhong with different fertilizers were investigated using experimental data from the Chinese Ecosystem Research Network at Taoyuan Station of Agro-ecology Research,Chinese Academy of Sciences.The field trials included no fertilizer（CK）,chemical fertilizer（NPK）,rice straw with low N,K and high P（optimal fertilization,OF） and rice straw with some amount of NPK（general fertilization,GF）.The results showed that fertilization was the basic mode of maintaining or increasing productivity of rice in paddy ecosystem.Productivity and stability were different in paddy ecosystems with different fertilizers.The total rice biomass was significantly higher in fertilizer treatments than in no fertilizer treatments;0.33~1.23 times higher for the period of 2005 to 2010.The order of stability from high to low was OF GF NPK CK.OF treatment improved total biomass stability in the study area.Yield under fertilizer treatments was 0.35~1.02 times higher than under no fertilizer treatment for the period of 2005 to 2010.It was 0.35 times higher in GF than CK in 2005,0.82 times higher in NPK than CK in 2007 and 1.02 times higher in OF than CK in 2010.The stability of rice yield was high in OF treatment and significantly low in CK treatment.Yearly variation coefficient under CK,NPK,OF and GF treatments was 22.4%,15.8%,10.3% and 15.7%,respectively.Productivity of underground biomass was significantly higher in fertilizer treatments than in no fertilizer treatment.Also ecological stability was significantly higher under GF treatment than the other treatments.In conclusion,rice productivity and production stability were highest under OF treatment and lowest under CK treatment.While fertilizers influenced rice yield stability and total or over-ground rice biomass,they little affected the stability of below-ground biomass productivity.