Soil mineral nitrogen and yield-scaled soil N2O emissions lowered by reducing nitrogen application and intercropping with soybean for sweet maize production in southern China
Soil mineral nitrogen and yield-scaled soil N_2O emissions lowered by reducing nitrogen application and intercropping with soybean for sweet maize production in southern China作者机构:Institute of Tropical and Subtropical Ecology~Key Laboratory of Agro-environment in the Tropics Ministry of Agriculture/KeyLaboratory of Agroecology and Rural Environment of Guangdong Regular Higher Education Institutions South China AgriculturalUniversity Guangzhou 510642 P.R. China
出 版 物:《Journal of Integrative Agriculture》 (农业科学学报(英文版))
年 卷 期:2017年第16卷第11期
页 面:2586-2596页
核心收录:
基 金:supported by the Key Technologies R&D Program of China during the 12th Five-year Plan period(2012BAD14B16-04) the Science and Technology Development Program of Guangdong,China(2012A020100003 and 2015B090903077)
主 题:sweet maize-soybean intercrop cropping system N fertilizer rate grain yield soil mineral N soil NzO emissions
摘 要:The increasing demand for fresh sweet maize (Zea mays L. saccharata) in southern China has prioritized the need to find solutions to the environmental pollution caused by its continuous production and high inputs of chemical nitrogen fertilizers. A promising method for improving crop production and environmental conditions is to intercrop sweet maize with legumes. Here, a three-year field experiment was conducted to assess the influence of four different cropping systems (sole sweet maize (SS), sole soybean (SB), two rows sweet maize-three rows soybean (S2B3) intercropping, and two rows sweet maize-four rows soybean (S2B4) intercropping), together with two rates of N fertilizer application (300 and 360 kg N ha-1) on grain yield, residual soil mineral N, and soil N2O emissions in southern China. Results showed that in most case, inter- cropping achieved yield advantages (total land equivalent ratio (TLER=0.87-1.25) was above one). Moreover, intercropping resulted in 39.8% less soil mineral N than SS at the time of crop harvest, averaged over six seasons (spring and autumn in each of the three years of the field experiment). Generally, intercropping and reduced-N application (300 kg N ha-1) produced lower cumulative soil N20 and yield-scaled soil N20 emissions than SS and conventionaI-N application (360 kg N ha-l), respectively. $2B4 intercropping with reduced-N rate (300 kg N ha-~) showed the lowest cumulative soil N20 (mean value=0.61 kg ha-1) and yield-scaled soil N20 (mean value=0.04 kg t-1) emissions. Overall, intercropping with reduced-N rate maintained sweet maize production, while also reducing environmental impacts. The system of S2B4 intercropping with reduced-N rate may be the most sustainable and environmentally friendly cropping system.