In order to reveal the effects of different organic fertilizers on nitrogen mineralization characteristics in a coal mining reclamation soil

a pot experiment was conducted by using a subsidence reclamation soil

which collected from Shuiyu Coal Mining in Xiaoyi City

Shanxi Province. The nitrogen mineralization dynamic characteristics of 0~161 days after application of three organic fertilizers (chicken manure

pig manure

cattle manure) were studied by indoor aerobic incubation method under 40% water content and 30℃ incubation conditions. The nitrogen supply characteristics of different organic fertilizers in the reclaimed soil of the mining area could be predicted

which could provide a scientific basis for the rational application of organic fertilizers for the fertility improvement of low-yield farmland. The results showed:(1) The dynamic trend of NH4+-N content in each treatment was basically same. The NH4+-N contents decreased rapidly with incubation time at 0~14 days

which were significantly negative correlation with the incubation time (P<0.01). The NH4+-N contents remained at the low level at 14~161 days. At the end of incubation

the content of NH4+-N in each treatment was lower than 1.31 mg/kg. (2) The dynamic trend of soil NO3--N content

NO3--N accumulation amount and mineral nitrogen accumulation showed an increased S-shaped curve in the whole incubation period

which slowly increased at 0~56 days

quickly increased at 56~84 days

and basically unchanged at 84~161 days. At the end of incubation (161 days)

the NO3--N content

NO3--N accumulation amount and mineral nitrogen accumulation varied among different treatments

with a sequence of chicken manure > pig manure > cattle manure > CK

and chicken manure treatment was significantly higher than pig manure treatment and cattle manure treatment

meanwhile pig manure treatment and cattle manure treatment were significantly higher than CK (P<0.05). (3) The time of nitrogen net mineralization in different fertilization treatments was different. The net mineralization of chicken manure occurred at 14 days

while the net mineralization of pig manure and cattle manure occurred after 28 days. (4) Although the accumulation rates of NO3--N and mineral nitrogen of different fertilization treatments at different periods of incubation were different

their trends were totally consistent

which showed that the soil mineralization rate fluctuated greatly at 0~84 days

peaked at 56~84 days

decreased steadily at 84~161 days. In a word

the application of organic fertilizer could effectively promote the nitrogen mineralization of reclaimed soil in coal mines

thereby improved soil nitrogen availability. Among three organic fertilizers

the application of chicken manure was better than pig manure and cattle manure in improving the available nitrogen in the reclaimed soil in the mining area. The effects of nitrogen mineralization varied with four treatments

with a sequence of chicken manure > pig manure > cattle manure > CK.