The new Caribbean Nitrogen Index to assess nitrogen dynamics in vegetable production systems in southwestern Puerto Rico

作     者：Miguel Oliveras-Berrocales David Sotomayor-Ramirez Jorge A.Delgado Luis R.Perez-Alegriad 

作者机构：USDA-NRCSArkansas:2603 Federal Building100 E8th AvePine BluffAR 71601USA University of Puerto RicoMayaguez CampusCollege of Agricultural SciencesDepartment of Agroenvironmental SciencesPO Box 9000MayagüezPR 00680USA USDA-ARSActing Research LeaderSoil Management and Sugar Beet Research Unit2150 Centre Ave.Building DSuite 100Fort CollinsCO 80526USA University of Puerto RicoMayaguez CampusCollege of Agricultural SciencesDepartment of Agricultural and Biosystems EngineeringUSA 

出 版 物：《International Soil and Water Conservation Research》 (国际水土保持研究（英文）)

年 卷 期：2017年第5卷第1期

页      面：69-75页

核心收录：

学科分类：0710[理学-生物学] 02[经济学] 0202[经济学-应用经济学] 0818[工学-地质资源与地质工程] 0903[农学-农业资源与环境] 0815[工学-水利工程] 0901[农学-作物学] 0833[工学-城乡规划学] 0713[理学-生态学] 0834[工学-风景园林学（可授工学、农学学位）] 

主　　题：Nitrogen index Nitrogen management Residual soil N Crop N removal 

摘      要：Nutrient loss from agricultural fields is one of the main factors influencing surface-and ground-water quality.Typical fertilizer nitrogen(N)consumption rates in vegetable production systems and horticultural crops in Puerto Rico fluctuate between 112 and 253 kg N/ha.The nitrogen use efficiency of vegetable crops is low,increasing the potential for nitrogen losses and high residual soil nitrate content.Quantification of residual soil N and N losses to the environment can be a difficult task.Simulation models such as the USDA-ARS N Index can be used to identify the relative magnitude of varying N-loss pathways and to identify best management practices.Field studies were conducted to quantify residual soil N and crop N removal,and to validate the Nitrogen Index in onion,tropical pumpkin and tomato production systems in the Lajas Valley in southwestern Puerto Rico.Relationships between observed and simulated values were determined to examine the capability of the model for evaluating N losses.There was good correlation between observed and predicted values for residual soil N(r=0.88)and crop N removal(r=0.99)(p0.05).In the production systems evaluated,the N volatilization losses ranged from 1 to 4 kg N/ha,the denitrification losses ranged from 18 to 46 kg N/ha,the leaching losses ranged from 155 to 779 kg N/ha,and the residual soil nitrate ranged from 64 to 401 kg N/ha.The N use efficiency ranged from 15% to 39%.The results obtained showed that the Nitrogen Index tool can be a useful tool for evaluating N transformations in vegetable production systems of Puerto Rico s semi-arid zone.