scholarly journals Mitigation of ammonia volatilization with application of urease and nitrification inhibitors from summer maize at the Loess Plateau

2018 ◽  
Vol 64 (No. 4) ◽  
pp. 164-172 ◽  
Author(s):  
Ahmed Muneer ◽  
Yu Weijia ◽  
Lei Ming ◽  
Raza Sajjad ◽  
Zhou Jianbin
Keyword(s):  
Loess Plateau ◽  
Field Experiments ◽  
Nitrification Inhibitors ◽  
Alkaline Soils ◽  
The Loess Plateau ◽  
Summer Maize ◽  
Band Placement ◽  
N Losses ◽  
Maize Crop ◽  
Meteorologic Factors

Field experiments were conducted at three sites: Yangling (YL); Zhouzhi-1 (ZH-1) and Zhouzhi-2 (ZH-2) of the Loess Plateau during summer maize crop, to investigate the effectiveness of N-(n-butyl) thiophosphoric triamide (NBPT) and NBPT + dicyandiamide (DCD) with urea on reducing NH<sub>3</sub> volatilization from different soils under different environmental conditions. Four treatments including control (no N), N-220 kg/ha, N-220 + NBPT and N-220 + NBPT + DCD were applied in two splits through the band placement method. Total NH<sub>3</sub>-N loss observed were 65.8, 40.5 and 20.1 NH<sub>3</sub>-N kg/ha (accounting for 29.9, 18.4 and 9.2% of N applied) from urea for YL, ZH-1 and ZH-2, respectively. The application of NBPT and NBPT + DCD significantly reduced NH<sub>3</sub> volatilization by 80–93% and 75–90%, respectively. The meteorologic factors such as precipitation, air temperature and wind speed significantly affected NH<sub>3</sub> volatilization. These results suggested that the amendment of urea with NBPT and NBPT + DCD have potential to mitigate NH<sub>3</sub>-N losses from alkaline soils in the Loess Plateau.

Dicyandiamide increased ammonia volatilisation and decreased carbon dioxide emission from calcareous soil during wheat–maize rotation on the Loess Plateau

Soil Research ◽  
2019 ◽  
Vol 57 (7) ◽  
pp. 767 ◽  
Author(s):  
Sajjad Raza ◽  
Xuesong Li ◽  
Na Miao ◽  
Muneer Ahmed ◽  
Zhanjun Liu ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Loess Plateau ◽  
Soil Ph ◽  
Co2 Emission ◽  
Calcareous Soil ◽  
Carbon Dioxide Emission ◽  
Nitrification Inhibitors ◽  
The Loess Plateau ◽  
N Losses ◽  
Nitrification Process

Nitrification inhibitors (NIs) have been found to retard the nitrification process, reduce N losses and increase nitrogen use efficiency; however, their effect on carbon dioxide (CO2) emission from calcareous soil has rarely been reported. A 2-year field experiment was conducted to study whether nitrification inhibition by dicyandiamide (DCD) has any effect on CO2 release from calcareous soil. The experiment comprised five treatments: a control (0 kg N ha–1) and two levels of N fertiliser applied on wheat (160 and 220 kg N ha–1) and maize (180 and 280 kg N ha–1) crops, with and without DCD. Compared with the control, a decrease in soil pH (mean 0.21 units in N fertiliser treatments without DCD and 0.11 units with DCD) and increases in cumulative CO2 emission (mean 17% and 23% in wheat and maize respectively) and cumulative ammonia (NH3) volatilisation (mean 28% and 446% in wheat and maize respectively) was recorded under all N fertilised treatments (with and without DCD). The application of DCD with N fertiliser retarded the nitrification process, as indicated by a higher NH4+-N and lower NO3–-N content, as well as a relatively higher soil pH, compared with application of N fertiliser without DCD. In addition, DCD application significantly reduced CO2 emission in both wheat (10–20%) and maize (13–14%) crops compared with crops grown with N fertiliser without DCD. However, the losses from NH3 volatilisation increased when DCD was applied at both N fertiliser levels in both wheat (38–41%) and maize (24–36%) crops. Inhibition of nitrification by DCD was more effective during the wheat than during maize season. Controlling nitrification using DCD is an effective approach to minimise CO2 emission from calcareous soils on the Loess Plateau; however, DCD application increases in NH3 volatilisation.

Soil water utilization with plastic mulching for a winter wheat-summer maize rotation system on the Loess Plateau of China

2018 ◽  
Vol 201 ◽  
pp. 246-257 ◽  
Author(s):  
Dianyuan Ding ◽  
Ying Zhao ◽  
Hao Feng ◽  
Robert Lee Hill ◽  
Xiaosheng Chu ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Soil Water ◽  
Loess Plateau ◽  
The Loess Plateau ◽  
Summer Maize ◽  
Water Utilization ◽  
Rotation System ◽  
Plastic Mulching

Coupling model of ecohydrology and simulation of typical shrub ecosystems on the Loess Plateau

2020 ◽  
Author(s):  
Yu Zhang ◽  
Xiaoyan Li ◽  
Wei Li ◽  
Weiwei Fang ◽  
Fangzhong Shi
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Loess Plateau ◽  
Field Experiments ◽  
Annual Precipitation ◽  
The Loess Plateau ◽  
Rainfall Interception ◽  
Area Index ◽  
Caragana Korshinskii

&lt;p&gt;Shrub is the main vegetation type for vegetation restoration in the Loess Plateau, which plays an important role in the regional ecosystem restoration. Study on the relationships between vegetation and soil water of typical shrub ecosystems are significant for the restoration and reconstruction of ecosystems in the Loess Plateau. Three typical shrub (&lt;em&gt;Hippophae rhamnoides&lt;/em&gt; Linn., &lt;em&gt;Spiraea pubescens&lt;/em&gt; Turcz., and &lt;em&gt;Caragana korshinskii&lt;/em&gt; Kom.) ecosystems were chosen in the Loess Plateau. Field experiments were conducted to investigate the factors that influencing the processes of rainfall interception and root uptake of typical shrubs. S-Biome-BGC model was established based on the Biome-BGC model by developing the rainfall interception and soil water movement sub-models. The model was calibrated and verified using field data. The calibrated S-Biome-BGC model was used to simulate the characteristics of leaf area index (&lt;em&gt;LAI&lt;/em&gt;), net primary productivity (&lt;em&gt;NPP&lt;/em&gt;), soil water content and the interactions among them for the shrub ecosystems along the precipitation gradients in the Loess Plateau, respectively. The results showed that the predictions of the S-Biome-BGC model for soil water content and&lt;em&gt; LAI&lt;/em&gt; of typical shrub ecosystems in Loess Plateau were significantly more accurate than that of Biome-BGC model. The simulated &lt;em&gt;RMSE&lt;/em&gt; of soil water content decreased from 0.040~0.130 cm&lt;sup&gt;3&lt;/sup&gt; cm&lt;sup&gt;-3&lt;/sup&gt; to 0.026~0.035 cm&lt;sup&gt;3&lt;/sup&gt; cm&lt;sup&gt;-3&lt;/sup&gt;, and the simulated &lt;em&gt;RMSE&lt;/em&gt; of&lt;em&gt; LAI&lt;/em&gt; decreased from 0.37~0.70 m&lt;sup&gt;2&lt;/sup&gt; m&lt;sup&gt;-2&lt;/sup&gt; to 0.35~0.37 m&lt;sup&gt;2&lt;/sup&gt; m&lt;sup&gt;-2&lt;/sup&gt;. Therefore, the S-Biome-BGC model can reflect the interaction between plant growth and soil water content in the shrub ecosystems of the Loess Plateau. The S-Biome-BGC model simulation for &lt;em&gt;LAI&lt;/em&gt;,&lt;em&gt; NPP&lt;/em&gt; and soil water content of the three typical shrubs were significantly different along the precipitation gradients, and increased with annual precipitation together. However, different &lt;em&gt;LAI&lt;/em&gt;, &lt;em&gt;NPP&lt;/em&gt; and soil water correlations were found under different precipitation gradients.&lt;em&gt; LAI&lt;/em&gt; and&lt;em&gt; NPP&lt;/em&gt; have significant positive correlations with soil water content in the areas where the annual precipitation is above 460~500 mm that could afford the shrubs growth. The results of the study provide a re-vegetation threshold to guide future re-vegetation activities in the Loess Plateau.&lt;/p&gt;

RECOVERY OF 15N-LABELLED UREA AS INFLUENCED BY STRAW ADDITION AND METHOD OF PLACEMENT

1989 ◽  
Vol 69 (3) ◽  
pp. 543-550 ◽  
Author(s):  
S. S. MALHI ◽  
M. NYBORG ◽  
E. D. SOLBERG
Keyword(s):  
Field Experiments ◽  
Heavy Rain ◽  
N Recovery ◽  
Band Placement ◽  
N Losses ◽  
North Central ◽  
Nest Placement ◽  
Method Of Placement ◽  
N Incorporation ◽  
Fall Application

Field experiments were conducted during 1982–1983 at two locations (Rimbey and Ellerslie) in north-central Alberta to determine the influence of date of application (mid-October, late October and spring), method of placement (incorporation, banding and nesting) and straw (0 and 3.4 t ha−1) on the recovery of 15N-labelled urea in plants and soil at harvest. The rate of N was 50 kg N ha−1. The recovery of 15N in mature barley plants at both locations was greater with spring application as compared to fall application, and greater with banding or nesting compared to incorporation. At Rimbey, the average recovery, in plants plus soil, of incorporated urea N was lower with October applications (43% for mid and 55% for late) as compared to spring application (89%). Banding or nesting increased the N recovery of October applications. With spring application, there was more immobilization of applied N when incorporated into soil as compared to band or nest placement. Also there was more immobilization of applied N when straw was added to the soil, but banding or nesting tended to overcome the immobilization effect of straw so that the plant N recovery was greater with banding or nesting as compared to incorporation. At the Ellerslie location, there was heavy rain with consequent saturated topsoil in late June and early July. Recovery of fall-applied N in plants was low, and even with nesting the recovery was only 13%. There was substantial immobilization of applied N at Ellerslie. With spring application, nesting overcame the large immobilization effect and produced normal recovery of applied N in the plants. Addition of straw resulted in more immobilization of applied urea N, particularly when urea was incorporated. The 15N recovery in plants plus soil of spring-applied N indicated N losses during the growing season and the losses were much greater at Ellerslie than at Rimbey. Key words: Band placement, fall application, immobilization of N, incorporation, 15N, N losses, nest placement, spring application

Sign in / Sign up

Export Citation Format

Share Document