摘要
在河南封丘潮土上进行了小麦、玉米轮作的长期肥料试验，对该长期试验的作物产量、氮利用率及其环境效应进行了分析。结果表明，在施氮量为150kg hm^-2季^-1的情况下，化肥N、P、K配合施用（NPK），小麦和玉米产量最高，且年际之间变化小，14a平均产量分别为5261kg hm^-2和7633kg hm^-2。在等N、P、K的情况下，1／2氮用有机肥（1／20M），作物产量略低于NPK；全部氮用有机肥（OM），平均产量分别降低22％和16％，产量年际变化大，但表现出随时间而提高的趋势。小麦和玉米氮肥平均利用率NPK分别为60％和61％、1／20M为51％和56％，OM为33、6％和42．5％。上述处理的表层土壤（0～20cm）全氮含量均显著增加，增加幅度依次递增；作物吸收和表层土壤残留氮合计占氮肥施用量的69％、75％和69％，均未发现NO3^-盐向土壤剖面深层的移动，N2O的排放系数〈0．24％。不施P肥的处理（NK），作物产量极低，氮肥利用率几乎为零，且有大量的NO3^-向剖面深层迁移，在0～100cm范围内，NO；含量随着深度的增加而提高，但N2O排放系数小于上述3处理。由此可以得出，在该土壤上采用小麦、玉米轮作，年氮施用量300kg hm^-2，如果配合P、K肥，可以持续保持较高的产量，且不造成NO3^-盐淋移和大量N2O排放。
Crop yield, N use efficiency, and environmental impact of a 14-year fertilization experiment with winter wheat and summer maize, carried out in fluvor aqutic soil in North China, were analyzed. The results show that Treatment NPK （150 kg hm^- 2 chemical N fertilizer per crop plus a set rate of P and K fertilizer） has always been the highest in yield of either winter wheat or maize with the smallest annual variation. The average yield of winter wheat （over 14 years） and maize （over 13 years） was 5 261 kg hm^-2 and 7 633 kg hm^-2, respectively. Treatment I/20M （i.e. half of N from chemical fertilizer and the other half from organic manure） was slightly lower than Treatment NPK in average yield of the crops, but in Treatment OM （only organic manure applied at the same rates of N, P, K as those in Treatment NPK）, the yields of winter wheat and maize on average were 22% and 16% lower than those in Treatment NPK, respectively, and varied significantly from year to year. The treatment showed a rising trend with the time in yield （p 〈 0.05）. The averaged N use efficiency was 60% for winter wheat and 61% for maize in Treatment NPK, 51% and 56% in Treatment 1/20M, and 34% and 43% in Treatment OM, respectively. Total N in the surface soil （0 ～20 cm） was increasing in all the above treatments, which were in the order of OM 〉 1/20M 〉 NPK. The amount of N recovered by the plants plus N residue in surface Soll （0 ～ 20 cm） accounted for 69%, 75 % and 69% , respectively in NPK, I/2OM, and OM. There was no evidence of downwards movement of NO3^- to subsoil and the N2O emission factors were less than 0.24% in all the three treatments. In contrast, NO3^- content increased with the depth of soil profile to 100 cm in Treatment NK, of which the crop yields were not significantly different from those in CK （without fertilization） and the N use efficiency was almost equal to zero, but its N2O emission factor was lower than those in Treatment NPK. These results indicate that in the investigated soil with winter wheat and maize crop in rotation, crop yields could be maintained at a high level by application of chemical N fertilizer at a rate of 150 kg hm^-2 and P and K fertilizers at a reasonable rate per crop season. In this case negative environmental impact was negligible.
出处
《土壤学报》
CAS
CSCD
北大核心
2006年第6期885-891,共7页
Acta Pedologica Sinica
基金
国家重点基础研究发展计划(973计划)(2005CB121101)资助
关键词
长期试验
小麦
玉米
氮利用率
环境影响
Long-term experiment
Winter wheat
Maize
N use efficiency
Environmental impact
