Ren Tao, Wang Jingguo, Chen Qing, Zhang Fusuo, Lu Shuchang
College of Resources and Environmental Science, China Agricultural University, Beijing, China; College of Resources and Environment, Huazhong Agricultural University, Wuhan, China.
College of Resources and Environmental Science, China Agricultural University, Beijing, China.
PLoS One. 2014 May 15;9(5):e97732. doi: 10.1371/journal.pone.0097732. eCollection 2014.
With the goal of improving N fertilizer management to maximize soil organic carbon (SOC) storage and minimize N losses in high-intensity cropping system, a 6-years greenhouse vegetable experiment was conducted from 2004 to 2010 in Shouguang, northern China. Treatment tested the effects of organic manure and N fertilizer on SOC, total N (TN) pool and annual apparent N losses. The results demonstrated that SOC and TN concentrations in the 0-10cm soil layer decreased significantly without organic manure and mineral N applications, primarily because of the decomposition of stable C. Increasing C inputs through wheat straw and chicken manure incorporation couldn't increase SOC pools over the 4 year duration of the experiment. In contrast to the organic manure treatment, the SOC and TN pools were not increased with the combination of organic manure and N fertilizer. However, the soil labile carbon fractions increased significantly when both chicken manure and N fertilizer were applied together. Additionally, lower optimized N fertilizer inputs did not decrease SOC and TN accumulation compared with conventional N applications. Despite the annual apparent N losses for the optimized N treatment were significantly lower than that for the conventional N treatment, the unchanged SOC over the past 6 years might limit N storage in the soil and more surplus N were lost to the environment. Consequently, optimized N fertilizer inputs according to root-zone N management did not influence the accumulation of SOC and TN in soil; but beneficial in reducing apparent N losses. N fertilizer management in a greenhouse cropping system should not only identify how to reduce N fertilizer input but should also be more attentive to improving soil fertility with better management of organic manure.
为了改善氮肥管理，以在高强度种植系统中最大限度地增加土壤有机碳（SOC）储量并减少氮素损失，于2004年至2010年在中国北方寿光进行了一项为期6年的温室蔬菜试验。该试验测试了有机肥和氮肥对土壤有机碳、全氮（TN）库以及年度表观氮损失的影响。结果表明，在不施用有机肥和矿物氮的情况下，0-10厘米土层中的土壤有机碳和全氮浓度显著下降，主要是由于稳定碳的分解。在试验的4年期间，通过添加小麦秸秆和鸡粪增加碳输入并不能增加土壤有机碳库。与有机肥处理不同，有机肥和氮肥组合并未增加土壤有机碳和全氮库。然而，当同时施用鸡粪和氮肥时，土壤活性碳组分显著增加。此外，与常规施氮相比，较低的优化氮肥投入并未降低土壤有机碳和全氮的积累。尽管优化施氮处理的年度表观氮损失显著低于常规施氮处理，但过去6年土壤有机碳未发生变化可能会限制土壤中的氮储存，更多的过剩氮流失到环境中。因此，根据根区氮管理进行优化氮肥投入不会影响土壤中有机碳和全氮的积累，但有利于减少表观氮损失。温室种植系统中的氮肥管理不仅应确定如何减少氮肥投入，还应更加注重通过更好地管理有机肥来提高土壤肥力。
