摘要
通过连续3年的冬小麦 夏玉米轮作试验研究高肥力土壤的供氮能力。结果表明,在本试验的高肥力土壤上,存在土壤供氮能力随时间延长而下降的趋势。但在连续3年3个轮作周期6季作物生长过程中,土壤都保持了较高的供氮能力,其中夏玉米季高于冬小麦季,不施氮处理在冬小麦季的相对产量保持在46%～76%,夏玉米季为69%～81%,轮作周期中土壤氮素的表观矿化量为125～184kg hm2,而供氮能力为123～190kg hm2。在考虑土壤供氮能力的基础上,基于土壤植株测试的氮肥优化管理,在连续6季作物中较大幅度地降低了氮肥用量,但却获得了同传统施氮处理一致的产量,保持了较低的土壤无机氮残留量,避免了过量施氮对环境的不良影响。
Continuous N-supplying capacity of the fertile soil in the winter wheat /summer maize rotation system was studied in a three-year experiment. Three N fertilization treatments, including no N fertilization treatment, optimized N fertilization treatment by soil N_(min) testing and plant nitrate testing, and conventional N fertilization treatment, were involved in this field experiment. The results indicated, that the soil N-supplying capacity declined with time run, especially in the third year. However, this experimental fertile soil maintained relatively high N-supplying capacity during whole three experimental years, and in summer maize growing season the soil N-supplying capacity was higher than that in the winter wheat growing season. The relative grain yield of no N fertilization treatment was 46%-76% in the winter wheat growing season and 69%-81% in the summer maize growing season. The calculated apparent N mineralization in each rotation period varied from 184 to 125 kg/hm^2 in the three experimental years, and the amount of soil N supplying which obtained from N uptake by crop at the no N fertilization treatment was 123-190 kg/hm^2. Because of taking soil N-supplying capacity in consideration, the optimized N fertilization treatment reached a same crops grain yield compared with the conventional N fertilization treatment, although its' N rate was much lower than that in the conventional N fertilization treatment. Moreover, soil residual N_(min) of the optimized N fertilization treatment was quite lower, which avoided the risk of N losses to the groundwater and atmosphere.
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2004年第1期1-5,共5页
Journal of Plant Nutrition and Fertilizers
基金
国家自然科学基金(300070451
60300001)
北京市自然科学基金重大项目(6010001)资助
关键词
冬小麦
夏玉米
轮作
高肥力土壤
土壤持续供氮能力
土壤氮矿化
winter wheat / summer maize rotation
N-supplying capacity of soil
nitrogen mineralization
fertile soil
