Nitrogen Transformations in Broiler Litter-Amended Soils

[摘要] Nitrogen mineralization rates in ten surface soils amended with (200 μg N g−1soil) or without broiler litter were investigated.The soil-broiler litter mixture was incubated at25±1C°for 28 weeks. A nonlinear regression approach for N mineralization was used to estimate the readily mineralizable organic N pools (N0) and the first-order rate constant (k). The cumulative N mineralized in the nonamended soils did not exceed 80 mg N kg−1soil. However, in Decatur soil amended with broiler litter 2, it exceeded 320 mg N kg−1soil. The greatest calculatedN0of the native soils was observed in Sucarnoochee soil alone (123 mgNO3 −kg−1soil) which when amended with broiler litter 1 reached 596 mg N kg−1soil. The added broiler litter mineralized initially at a fast rate (k1) followed by a slow rate (k2) of the most resistant fraction. Half-life of organic N remaining in the soils alone varied from 33 to 75 weeks and from 43 to 15 weeks in the amended soils. WhenN0was regressed against soil organic N (r=0.782**) and C (r=0.884***), positive linear relationships were obtained. TheN0pools increased with sand but decreased with silt and clay contents.

[学科分类] 农艺学与作物科学