摘要
1 999年以不同施肥制度对红壤稻田系统生产力和土壤环境影响的长期定位试验的为依托 ,比较研究了 9a定位试验后 ,不施肥、单施无机肥、有机物循环和有机无机结合施肥对红壤稻田生态系统土壤供氮能力、水稻吸氮特性和水稻生产的影响。结果表明 :红壤稻田系统长期不施肥 (CK)土壤速效氮含量低 ,最高为 1 6 .7mg/kg,平均为 1 4.2 mg/kg,水稻累积吸收氮量较少 ,早稻为 3 2 .84kg/hm2 ,晚稻为 5 9.79kg/hm2 ,系统生产力低 ,早稻生物量为 3 887kg/hm2 ,稻谷产量为 2 1 80 kg/hm2 ,晚稻生物量为 71 6 4 kg/hm2 ,稻谷产量为3 71 9kg/hm2 ;施用 N肥可以改善土壤供氮状况 ,提高土壤速效氮含量 ,且 N、NP、NK、NPK处理间没有显著差异 ,土壤速效氮含量最大可达到 2 9.7mg/kg,平均为 2 1 .4mg/kg,而水稻累积吸收氮量与系统生产力随着 NPK配合程度的增加而提高 ,NPK处理的早稻累积吸收氮量、生物量和稻谷产量分别比 CK处理增加1 2 2 .6 %、87.1 %和 6 5 .4% ,晚稻分别增加 85 .0 %、48.2 %和 46 .0 % ;系统内有机物循环利用 (C)水稻各生育期土壤速效氮含量显著提高 ,最高为 3 0 .2 mg/kg,平均为 2 0 .8mg/kg,水稻累积吸收氮量早、晚稻分别比 CK增加 1 1 1 .1 %和 48.9% ,早稻生物量与稻谷产量显分别比 CK高 85 .6
A field study was conducted at the Taoyuan Experimental Station of Agro-ecosystem Observation, to investigate the long-term (9 years) effects of different fertilization systems on rice productivity, nitrogen absorption by the crops at different growth stages and the nitrogen supplying capacity of soils in the red earth region of China.; The experiment had a total of ten treatments. (1) A control treatment ‘CK', in which no fertiliser or recycled crop nutrients were applied; (2) treatment ‘C', in which crop nutrients were recycled but no fertiliser was applied; (3) treatment ‘N', in which nitrogen fertiliser (urea) alone was applied at N 262.5kg/(hm 2·a) (pre-1997) and at N 182.3kg/(hm 2·a) (post-1997) with no recycling of crop nutrients; (4) treatment ‘N+C', which was simply treatments N and C combined; (5) treatment ‘NP', which was treatment N plus P39.3 kg(hm 2·a) as single-superphosphate; (6) treatment ‘NP+C', which was treatments NP and C combined; (7) treatment ‘NK', which was treatment N plus K 197.0 kg/(hm 2·a) (post-1997) as potassium chloride (K 137.0 kg/(hm 2·a) (pre-1997); (8) treatment ‘NP', which was treatment NK plus P 39.3 kg/(hm 2·a) as single-superphosphate; (9) treatment ‘NPK+C', which was treatment NPK plus treatment C; (10) treatment ‘F+1/2C', which was nitrogen, phosphorus and potassium applied at rates N 121.5 kg/(hm 2·a) (N 175.5 kg/(hm 2·a)(pre 1997), P 26.2 kg/(hm 2·a) and K 65.7 kg/(hm 2·a) (K 45.7 kg/(hm 2·a) (pre-1997), respectively, and only 1/2 the rice straw recycled to the plots.; Each treatment had three replicates, which were arranged in fully randomized blocks. For the treatments in which there was no recycling of crop nutrients, Chinese milk vetch was cultivated in winter from 1990 to 1994 (but not after 1994) and the upper parts of the green manure harvested and removed from the field before spring plowing. For the treatments in which there was recycling of crop nutrients (C), Chinese milk vetch was cultivated in winter and ploughed into the field. Rice straw was also fully returned to the field after harvesting and 80% of the full grains (50% after 1995) and all of the empty or blighted grains were fed to pigs, and the pig muck subsequently spread on the field. ; Soil samples were collected from all plots at seven growth stages: (1) prior to early rice transplanting, (2) at transplanting-tillering, (3) at tillering-heading (4) at heading-maturity (5) at late rice transplanting (6) at tillering-heading, (7) at heading-maturity. Multiple soil cores were taken from each plot with an auger to a depth of 200mm and mixed to form composite samples. Fresh soil samples were extracted with 2mol/L KCl and analysed for mineral nitrogen (NO+--3-N and NH++-4-N) by steam distillation and titration. Soil moisture contents were determined to convert the nitrogen results to units of nitrogen per kilogram of dry soil. Samples of rice plants were collected from each plot on the same dates that the soil samples were collected. The samples were oven-dried at 80℃, milled, and analysed for total nitrogen by the Kjeldahl digestion method. Based on the soil mineral nitrogen results, the treatments can be divided into four different groups. The lowest level of soil mineral nitrogen (14mg N/kg on average over all 7 samplings) was found in the control treatment CK. The next lowest level (21mg N/kg on average over all 7 samplings), however, encompassed the four full rate fertiliser treatments (N, NP, NK, and NPK), and also treatment C, in which crop nutrients alone had been recycled and no fertiliser had been applied. This is interesting because it implies that recycling of crop nutrients alone had supplied as much nitrogen as the full N application rate. The second highest level of mineral nitrogen (N26mg/kg on average over all 7 samplings) was found in treatment F+1/2C, in which only 2/3 of the N application rate had been applied and only half the straw had been recycled. The highest level (N31mg/kg on average over all 7 samplings) was found in the three
出处
《生态学报》
CAS
CSCD
北大核心
2003年第5期914-921,共8页
Acta Ecologica Sinica
基金
中国科学院知识创新资助项目 (KZCX2 -4 0 7)~~
关键词
施肥
红壤稻田
土壤
氮素
水稻
生产效益
无机肥
有机肥
recycling of crop nutrients
rice
soil mineral nitrogen
profits of rice production
