^(15)N示踪研究氮肥中N对土壤硝酸盐形成和积累的影响  

STUDY ON FORMATION AND ACCUMULATION OF SOIL NITRATE INFLUENCED BY FERTILIZER NITROGEN WITH ^(15)N TRACING TECHNIQUE

作　　者：郭智芬[1] 潘勇[1] 涂书新[1] 张宜春[1] 林若泰[1] 

机构地区：[1]湖北省农科院原子能应用研究所

出　　处：《同位素》1996年第4期200-206,共7页Journal of Isotopes

摘　　要：应用１５Ｎ示踪技术，通过在生产条件下的盆钵试验，研究施入土壤中的化学氮肥经硝化形成ＮＯ３－Ｎ的动态变化及其对土壤硝酸盐形成积累的影响。研究证明，不同肥力灰潮土、不同施Ｎ量和不同施Ｎ比例，氮肥中Ｎ在土壤中净硝化形成积累ＮＯ３－Ｎ量的动态变化均符合Ｎｔ＝ａｔｅｂｔ数学模型；施Ｎ量增加时ＮＤＦＦ（来自氮肥的ＮＯ３－Ｎ量）随之成线性增加；土壤ＮＯ３－Ｎ量出现高峰与土壤中ＮＤＦＦ的高峰同步，说明ＮＤＦＦ是造成土壤高硝酸盐的主要原因；基、追肥比例８：１：１比６：２：２好，重施基肥不仅能提供蔬菜生长期充足的Ｎ素养分，而且还可能在收获期降低蔬菜中硝酸盐含量。氮肥中Ｎ在土壤中的净硝化率最高达４２％，因土壤肥力和施Ｎ量不同而异。By using 15N tracing technique,the drnamic change of soil nitrate from fertilizer N and its influence to soil nitrate accumulation are studied through pot experiments under usual cultivating condition.The results show that the dynamic changes of net amount of formed and accumulated nitrate from fertilizer N(NDFF)in soil with different fertilities, under different amount of N fertilizer,and in different ratios of basal and split application,accord with the mathematicc model: Nt=atebt.NDFF increase linearly along with the increase of the amount of N fertilizer. The peak of soil nitrate content appears synchronously with the peak of soil NDFF.It shows that NDFF is the major factor causing high content of soil nitrate.The ratio of hasal and split dressing of N fertilizer 8: 1: 1 is better than 6:2:2.Heavy amount of hasal N fertilizer not only supply sufficient N nutrient for vegetable growth, but the decrease the nitrate content of vegetable during harvest.The maximum nitrification ratio of fertilizer N in soil is up to 20%-42%, according to the soil fertility and rate of fertilizer N applied.

关 键 词：^(15)N示踪 硝酸盐 形成 积累 硝化率 

分 类 号：S153.61[农业科学—土壤学]