Details

Autor(en) / Beteiligte

• He, Y.T.
• Zhang, W.J.
• Xu, M.G.
• Tong, X.G.
• Sun, F.X.
• Wang, J.Z.
• Huang, S.M.
• Zhu, P.
• He, X.H.

Titel

Long-term combined chemical and manure fertilizations increase soil organic carbon and total nitrogen in aggregate fractions at three typical cropland soils in China

Ist Teil von

• The Science of the total environment, 2015-11, Vol.532, p.635-644

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2015

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Soil organic carbon (SOC), total nitrogen (TN), microbial biomass carbon (MBC) and nitrogen (MBN) are important factors of soil fertility. However, effects of the combined chemical fertilizer and organic manure or straw on these factors and their relationships are less addressed under long-term fertilizations. This study addressed changes in SOC, TN, MBC and MBN at 0–20cm soil depth under three 17years (September 1990–September 2007) long-term fertilization croplands along a heat and water gradient in China. Four soil physical fractions (coarse free and fine free particulate organic C, cfPOC and ffPOC; intra-microaggregate POC, iPOC; and mineral associated organic C, MOC) were examined under five fertilizations: unfertilized control, chemical nitrogen (N), phosphorus (P) and potassium (K) (NPK), NPK plus straw (NPKS, hereafter straw return), and NPK plus manure (NPKM and 1.5NPKM, hereafter manure). Compared with Control, manure significantly increased all tested parameters. SOC and TN in fractions distributed as MOC>iPOC>cfPOC>ffPOC with the highest increase in cfPOC (329.3%) and cfPTN (431.1%), and the lowest in MOC (40.8%) and MTN (45.4%) under manure. SOC significantly positively correlated with MBC, cfPOC, ffPOC, iPOC and MOC (R2=0.51–0.84, P<0.01), while TN with cfPTN, ffPTN, iPTN and MTN (R2=0.45–0.79, P<0.01), but not with MBN, respectively. Principal component analyses explained 86.9–91.2% variance of SOC, TN, MBC, MBN, SOC and TN in each fraction. Our results demonstrated that cfPOC was a sensitive SOC indicator and manure addition was the best fertilization for improving soil fertility while straw return should take into account climate factors in Chinese croplands. •Assessed the effects of 17years fertilization on SOC, TN and its fractions.•Manure increased all indexes but straw return had no effects on all indexes at GZL.•Chemical fertilization had no effects on TN but decreased MBC in GZL and QY.•cfPOC was the most sensitive indicator and MOC, MTN was the main sequestrated form.•Straw return was site-dependent and manure was the best for improving soil quality.