The petroleum pool character of storage layers consist itself and the accumulation meshwork layers, and the latter include primary reservoir and secondary reservoir.
The results show the amounts of NO3-N accumulation in the soil profiles and their extents to leach into the deeper soil layers are increased significantly as the nitrogen fertilizer usage increased.
结果表明：随着氮肥用量的提高，土壤剖面硝态氮累积量明显增加，其向土壤下层淋溶的程度也越严重；
3
On the longitudinal hole reservoir distribution has better layers, D accumulation ability is best;