Losses of NO and N₂O emissions from Venezuelan and other worldwide tropical N‐fertilized soils

Abstract

[1] N fertilization significantly increases N 2 O and NO soil fluxes to the atmosphere. In spite of the expansion of agricultural activities in tropical managed soils from the developing world, there is little information about the loss of applied nitrogen (LAN) as NO and N 2 O from these areas. In this work, we determined LAN-N 2 O and LAN-NO from different crops during the growing season at a sandy soil experimental field and two active farms with loamy and clay soils, respectively. Tillage (T) and no-tillage (NT) farming were separately evaluated. All of the evaluated areas were located in the Venezuela savanna region. A large range of LAN-N 2 O (0.30-6.1%) and LAN-NO (0.26-2.1%) were recorded, with overall average values of 1.9% and 0.9%, respectively. LAN values were mainly affected by soil texture and rainfall pattern, which affected soil moisture and water-filled pore space. Also, soil management (T and NT) and the chemical composition of the N fertilizer played important roles. The overall average of LAN-N 2 O is about two times higher than the IPCC default value of 1%; therefore, our results suggest that a higher factor should be considered for cropping systems in tropical savanna regions.

The mechanisms governing low denitrification capacity and high nitrogen oxide gas emissions in subtropical forest soils in China

“…A previous investigation suggested that the denitrification process was the main source of N 2 O emission in subtropical forest soils [ Zhang et al , ]. Marquina et al [] have also reported that the loss of applied nitrogen as N 2 O and NO is higher than the Intergovernmental Panel on Climate Change default value in cropping systems of the tropical savanna region.…”

N2O emissions from banana plantations in tropical China as affected by the application rates of urea and a urease/nitrification inhibitor

“…In comparison with temperate and subtropical regions, the studies concerning N 2 O emissions from tropics are currently limited (Mosier et al 2004;Marquina et al 2013). To make a global comparison, we compiled the available literature data (Fig.…”

“…Banana cultivation is characterized by high N fertilization rates, frequent irrigation, and high temperatures (Veldkamp and Keller 1997;Irizarry et al 2002). The N application rate (in the form of mineral fertilizer and poultry manure) is as high as 500-1300 kg N ha −1 (Al-Harthi and Al-Yahyai 2009; Yao et al 2009;Al-Busaidi 2013), which is significantly higher than that used in other food crops (e.g., rice, wheat, and maize) (Watanabe et al 2000;Weitz et al 2001;Khalil et al 2002;Marquina et al 2013). In addition, multiple topdressings in combination with irrigation are also utilized during the banana-growing season (Veldkamp and Keller 1997).…”

“…To date, several studies have focused on investigating N 2 O emissions from wheat, corn, rice, and vegetable fields in China (Meng et al 2005;Pang et al 2009;Ding et al 2011;Liu et al 2014), but these studies were largely conducted in temperate and subtropical regions. Considering the characteristic of climate (e.g., high temperature and frequent rainfall) and increasing N input in tropics, N 2 O emissions from this regions have been receiving widespread attention (Mosier et al 2004;Marquina et al 2013). Banana, the important tropic fruit, is grown on over 10 million hectares in tropical and subtropical regions, with total production of approximately 138 million tons (FAOSTAT 2010).…”

“…This great variation is probably caused by a combination of soil properties (e.g., texture, pH), management (e.g., tillage, straw returning), environmental conditions (e.g., temperature, rainfall), N fertilizer (e.g., types, application rates), and cultivated crops(Mosier and Delgado 1997;Weitz et al 2001;Mosier et al 2004;Marquina et al 2013). Based on our results (1.76-2.31 %) and those (1.26-2.92 %) of Veldkamp andKeller (1997), we can see clearly that the EF values of banana plantations were obviously higher than those of most tropical row crops (e.g., maize, sorghum, corn), which may be attributed by the great difference in rate and frequency of N fertilizer application (Veldkamp and Keller 1997;Mosier et al 2004).…”