【作者】 王鑫；

【导师】 张卫建；

【作者基本信息】 南京农业大学 ， 生态学， 2011， 硕士

【摘要】 施肥是维持和提高作物产量的重要途径,对我国粮食增产的贡献率已达到50%以上。但是,不合理的施肥方式容易导致土壤退化和质量下降,从而影响作物产量的持续提升。江南丘陵是我国双季稻主产区,江西稻田是该区域的典型代表,在我国中长期粮食安全保障中起着关键作用。研究不同施肥模式对江西双季稻田系统生产力的长期影响,对保障我国南方双季稻生产的可持续性和粮食安全具有重要意义。本研究依据29年的田间施肥小区试验和4年的养分耗竭盆栽试验,分析比较了长期不同施肥下稻田系统生产力、物质生产效率的差异,通过对不同施肥处理下稻田生产力的变化趋势、变异系数和产量可持续指数(SYI)等相关参数的分析研究,阐明了长期不同施肥措施对江西稻田生产力和抗逆性的综合效应。本研究主要结果如下：1.长期氮磷钾单施在短期对双季稻有增产效应,其中,氮肥增产效果更显著。单施氮肥(N)增产年限约为16年,随时间推移,增产优势减弱。试验进行29后,N、P、K处理籽粒产量分别与对照相差9.8%、-6.1%、-1.0%,与对照之间差异不显著。长期缺失氮肥(PK)生产力显著低于NP、NK处理,多年籽粒产量均值分别比上述处理低15.0%、14.8%。平衡施肥处理(NPK和NPK+OM)生物量、产量始终高于其他施肥处理。其中有机无机配施(NPK+OM)生物量、产量始终显著高于化肥氮磷钾配施(NPK)处理,其周年平均生物量和籽粒产量比氮磷钾配施的高24.5%和20.2%。只有NPK+OM、P处理周年籽粒产量呈现上升趋势(6.9 kg hm-2 a-1、5.2 kg hm-2 a-1),未达到显著水平。2.与其他施肥处理相比,单施氮肥降低了双季稻周年生物量的变异系数(CV)、提高双季稻周年生物量的可持续性指数(SYI),其次是氮磷钾配施(NPK)处理；无论早稻还是晚稻季,平衡施肥处理(NPK、NPK+OM)下产量变异系数均小于其他处理,产量可持续性指数均大于其他处理。虽然N处理下生物量生产稳定性较高,但其生产力水平低。可见,只有平衡施肥能够确保双季稻田系统持续高产、稳产。3.在养分耗竭试验中,单施氮肥的稻田系统耐瘠能力好于单施磷肥和单施钾肥,其周年生物量、籽粒产量均值分别比上述处理高3.5%、3.7%,6.2%、8.0%。长期单施磷肥的稻田系统退化严重,耐瘠力差,偏施NK处理产量以-5.0 g pot-1 a-1的速度呈显著下降趋势,可见长期单施磷肥以及长期缺失磷肥对稻田系统的耐瘠性都有负面影响,因此在红壤稻田系统中合理配施磷肥才能有效地提高系统的耐瘠能力。耗竭试验4年后,各季及周年水稻的生物量和籽粒产量均以NPK+OM处理最高,而且试验期内生物量、籽粒产量均值也以NPK+OM处理为最高,说明有机无机配施的稻田土壤耐瘠能力高于其它施肥处理。可见,有机无机配施不仅能使稻田系统持续保持较高的生产力,而且能够提升系统的抗逆性,有利于江西双季稻田系统持续高产稳产。4.施氮肥的处理降低了氮收获指数,PK处理氮收获指数最高,显著高于N、NPK+OM、NP、NPK处理。氮肥施用量相等的情况下,氮肥利用效率随着氮磷钾配施水平的提高而增加,氮肥利用效率大小表现为：NPK>NP, NK>N;在氮磷钾配基础上适量加施有机肥同样能够提高氮肥利用效率。更多还原

【Abstract】 Fertilization is an important way to increase crop yield and contributes more than 50% to food production increment in China. However, unreasonable fertilization can lead to soil degradation and soil quality decline, and thus may influence the sustainable increase in crop yield. The hilly areas south of the Yangtze River are the main production areas for double rice and play a key role in the long-term food security in our country. Jiangxi is a typical region of the tested areas. It is of important significance for sustainable double rice production and food security in our country to study the long-term impact of different fertilization regimes on the productivity of double cropping rice systems. Therefore, through a 29-year (1981-2009) fertilization experiment in fields and a 4-year (2006-2009) nutrient depletion experiment with pots in Jiangxi province, we analyzed and compared the differences of crop productivity and dry matter production efficiency among different fertilization management. Through investigating the trends of crop productivity, coefficient of variation, and sustainable yield index (SYI) in the double rice cropping system, we elucidated the integrated effects of long term different fertilization regimes on the productivity and stress resistance of the agroecosystems. The main results were as follows:1. Only under N, P, and K fertilization, the yield of the double rice increased significantly in the short term. The chemical N could increase yield within 16 years, but the effects decreased with years. After 29 years, the yield of N, P and K treatments were close to the control by 9.8%,-6.1%,-1.0%. and there was no significant difference between them. The productivity of the treatment without N fertilizer (PK) was lower than NP, NK treatment significantly, whose mean value of yield was lower than the above two treatments by 15.0% and 14.8%. The balanced fertilization treatment (NPK and NPK+OM) had the significant biomass and yield in all the treatments all over the experiment. The application of NPK+OM gained both the highest mean aboveground biomass and mean grain yield that were 24.5% and 20.2% higher than those in the NPK treatment, respectively. The annual grain yield only in NPK+OM treatment and P treatment showed increasing trends, which inclined by 6.9 kg hm-2 a-1 and 5.2 kg hm-2 a-1 respectively.2. Compared with other treatments, only N fertilizer treatment decreased the annual biomass coefficient of variation (CV) of double rice, increased the annual biomass sustainable index of double rice. The next effects are NPK treatment. In balanced fertilizer treatments (NPK. NPK+OM), no matter early rice or late rice, the yield CV was the least and the sustainable yield index (SYI) was the highest. Although the stability of biomass production was higher the productivity was lower. Therefore, only balanced fertilizer can assure the high and stable yield in double rice ecosystem.3. In the soil nutrient depletion experiment, the tolerance ability of paddy ecosystem was higher in the only N fertilizer treatment than in only P or only K fertilizer treatment. The annual biomass was 3.5% and 3.7% higher in only N fertilizer treatment than in only P or only K fertilizer treatment and the annual yield mean was 6.2% and 8.0% higher. The paddy ecosystem under only P fertilizer degraded seriously and had lower tolerance ability. The yield significantly decreased at -5.0 g pot-1 a -1 in partial application of NK. So. the only long term P fertilizer application or long term P fertilizer absence had negative impacts on paddy ecosystem. Therefore, reasonable combined application of P fertilizer can effectively increase the tolerance ability in red soil paddy ecosystem. After four years operation of soil nutrient depletion experiment, the seasonal or annual biomass and yield of rice was the highest in NPK+OM treatment. And the biomass and yield means was also the highest in NPK+OM treatment. These results indicated that the tolerance ability under combined organic fertilizer and inorganic fertilizer was the highest. Therefore, the combined application of organic and inorganic fertilizer can not only maintain high productivity in paddy ecosystem but also increase the stress resistance of paddy ecosystem, facilitating the high and stable yield of double rice system in Jiangxi.4. The N harvest index was significantly reduced by N fertlizaiotn. which was highest in the PK treatment significantly higher than that in the N、NPK+OM、NP. and NPK treatments. Under application of the same amount of N, N use efficiendy (NUE) increased with the increasing application of P and K fertilizers, which was in the order:NPK> NP, NK> N. Application of NPK combined with organic manure can increase the NUE as well.更多还原