Zotarelli Lincoln, Scholberg Johannes M, Dukes Michael D, Muñoz-Carpena Rafael
University of Florida, IFAS, Agronomy Department, Gainesville, FL 32611, USA.
J Environ Qual. 2007 May 25;36(4):953-62. doi: 10.2134/jeq2006.0292. Print 2007 Jul-Aug.
Proper N fertilizer and irrigation management can reduce nitrate leaching while maintaining crop yield, which is critical to enhance the sustainability of vegetable production on soils with poor water and nutrient-holding capacities. This study evaluated different methods to measure nitrate leaching in mulched drip-irrigated zucchini, pepper, and tomato production systems. Fertigation rates were 145 and 217 kg N ha(-1) for zucchini; 192 and 288 kg N ha(-1) for pepper; and 208 and 312 kg N ha(-1) for tomato. Irrigation was either applied at a fixed daily rate or based on threshold values of soil moisture sensors placed in production beds. Ceramic suction cup lysimeters, subsurface drainage lysimeters and soil cores were used to access the interactive effects of N rate and irrigation management on N leaching. Irrigation treatments and N rate interaction effects on N leaching were significant for all crops. Applying N rates in excess of standard recommendations increased N leaching by 64, 59, and 32%, respectively, for pepper, tomato, and zucchini crops. Independent of the irrigation treatment or nitrogen rate, N leaching values measured from the ceramic cup lysimeter-based N leaching values were lower than the values from the drainage lysimeter and soil coring methods. However, overall nitrate concentration patterns were similar for all methods when the nitrate concentration and leached volume were relatively low.
合理的氮肥和灌溉管理可以减少硝酸盐淋失，同时维持作物产量，这对于提高保水保肥能力差的土壤上蔬菜生产的可持续性至关重要。本研究评估了测量覆盖滴灌西葫芦、辣椒和番茄生产系统中硝酸盐淋失的不同方法。西葫芦的施肥量分别为145和217千克氮/公顷；辣椒为192和288千克氮/公顷；番茄为208和312千克氮/公顷。灌溉要么以固定的日灌水量进行，要么基于放置在生产床中的土壤湿度传感器的阈值进行。使用陶瓷吸盘测渗仪、地下排水测渗仪和土芯来研究施氮量和灌溉管理对氮素淋失的交互作用。灌溉处理和施氮量对所有作物的氮素淋失交互作用均显著。对于辣椒、番茄和西葫芦作物，施氮量超过标准推荐量分别使氮素淋失增加了64%、59%和32%。无论灌溉处理或氮肥用量如何，基于陶瓷杯测渗仪测得的氮素淋失值均低于排水测渗仪和土芯取样法测得的值。然而，当硝酸盐浓度和淋失量相对较低时，所有方法的总体硝酸盐浓度模式相似。
