Effect Of Long-Term Fertilization On Organic Carbon And Nitrogen In Black Soil

Black soil contents lots of organic matter,after tillige,organic matter lost rapidly under humenbeing huodng.jn.It is very important to searching effective fertlilization to control its decrease and improve prodiction .Organic matter are mainly composed of carbon and nitrogen.This paper studied the effect of long-term ferlilization on organic carbon and nitrogen in black soil. Five treatments are as follows: no ferlilization (CK);chemical ferlilization(NPK);chemical ferlilization+low mounts of straw(NPK+S1);chemical ferlilization+low mounts of straw(NPK+S2);chemical ferlilization+manure(NPK+OM)。No ferlilizer made TOC decreased 4.38% during 14 years;TOC also decreased 3.31% under chemical ferlilizer, and compared with CK, TOC didn't improved.;chemical fertilizer plus straw or manure inhibtive its lose,TOC maintained at original level during 14 years,compared with CK,TOC improved.The result show that no ferlilization and chemical fertilization can not maintain TOC in black soil, while chemical ferlilization plus straw or manure properly can maintain TOC or increase . ROC decreased under no ferlilizer and all ferlilizers improved ROC around 22.97%~26.13%, among them organic inorganic can make ROC improved 10.12%~15.18%. chemical fertilizer plus nanure are better than that of straw ,and low amount of straw are better than high amount of straw. LFOC show the same trend with ROC :fertilization nominately improved LFOC in black soil,differently, its range between 41.46%~143.00%。Inlabile organic carbon pool (HA-C)and(FA-C)changed as followed:HA-C and FA-C are both decreased under any ferlilization,HA-C decareased between 9.08%~23.16%;that of FA-C is between 7.36%~23.96%. Fertilization can slow down its velocity,compared with no fertilizer, organic plus inorganic are better, HA-C improved between 8.23%~18.33%.Straw are better than manure and low amount of straw are better than high amount of that. Chemical ferlilizer improved FA-C with 9.67%,organic plus inorganic ferlilizer decreased HA-C,especially chemical plus low amounts of straw (9.98%) .The value of HA-C/FA-C of NPK+S1 is the highest among five treatments , the second is NPK+S2,and the third is NPK+OM,that of NPK is consistent with CK.The result show that chemical fertilizarion plus with straw or manure are benefit for carbon to transmit to HA-C pool. Only chemical fertilizer can not change the destribute of carbon in humus。Total Nitrogen (TN)decreased under any treatments including CK, but organic manure plus inorganic chemical ferlilizer inhabit it's V of decreased.Compared with CK, TN increased between 2.21%~3.10%. C/N maintained around 12 during 14 years。Long-term fertilization have great effect on compose of organic nitrogen. Ferlilization increased Acidolysis N with 15.59%~33%. Among them, Amino N,Aminia N and unknown N increased while Aminosugar N decreased. Acidolysis N,Amino N and Aminosugar N are easy to mineralize, so manure and straw play important role to increase organic nitrogen pool. Effect of ferlilization on component of inorganic N are as follows: fertilizer have great effect on NH4-N, Compared with CK, after ferlilizer contents of NH4-N is 2~6 times than that of CK. Chemical fertilizer plus manure or straw (5~6 times)are better than NPK treatment(2~2.6 times), Fertilizer have the same affect on NO3-N, differently , NPK treatment improved NO3-N obviously than other treatment. After suplus with straw or manure, the proportion of NH4-N are higher than that of NO3-N. so organic matter are benifeit to accumulate N to NH4-N, so that control the lose of NO3-N which contaminated environment.