The effects of manure and nitrogen fertilizer applications on soil organic carbon and nitrogen in a high-input cropping system.
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.
College of Resources and Environmental Science, China Agricultural University, Beijing, China; College of Resources and Environment, Huazhong Agricultural University, Wuhan, China.
Tao
T
Ren
College of Resources and Environmental Science, China Agricultural University, Beijing, China.
Jingguo
J
Wang
College of Resources and Environmental Science, China Agricultural University, Beijing, China.
Qing
Q
Chen
College of Resources and Environmental Science, China Agricultural University, Beijing, China.
Fusuo
F
Zhang
Department of Agronomy, Tianjin Agricultural University, Tianjin, China.
Shuchang
S
Lu
D002244:Carbon / Q000032:analysis / Q000737:chemistry*; D018556:Crops, Agricultural / Q000254:growth & development; D005308:Fertilizers; D018551:Solanum lycopersicum / Q000254:growth & development; D008372:Manure; D009584:Nitrogen / Q000032:analysis / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*
D005308:Fertilizers; D008372:Manure; D012987:Soil; D002244:Carbon; D009584:Nitrogen