Throughfall reduction diminished the enhancing effect of N addition on soil N leaching loss in an old, temperate forest

The impact of organic, compared with conventional, farming practices on N leaching loss was studied for Danish mixed dairy and arable farms using an N balance approach based on representative data. On mixed dairy farms, a simple N balance method was used to estimate N surplus and N leaching loss. On arable farms, the simple N balance method was unreliable due to changes in the soil N pool. Consequently, the Farm ASSEssment Tool (FASSET) simulation model was used to estimate N surplus, N leaching loss and the changes in the soil N pool.The study found a lower N leaching loss from organic than conventional mixed dairy farms, primarily due to lower N inputs. On organic arable farms, the soil N pool increased over time but the N leaching loss was comparable with conventional arable farms. The soil N pool was increased primarily by organic farming practices and incorporation of straw. The highest increase in the soil N pool was seen on soils with a low initial level of organic matter. The N leaching loss was dependent on soil type, the use of catch crops and the level of soil organic matter, whereas incorporation of straw had a minor effect. N leaching was highest on sandy soils with a high level of soil organic matter and no catch crops. The present results stress the importance of using representative data from organic and conventional farming practices in comparative studies of N leaching loss. Lack of representative data has been a major weakness of previous comparisons on N leaching losses on organic and conventional farms.

Download Full-text

Response of Vertical Migration and Leaching of Nitrogen in Percolation Water of Paddy Fields under Water-Saving Irrigation and Straw Return Conditions

Water ◽

10.3390/w11040868 ◽

2019 ◽

Vol 11 (4) ◽

pp. 868 ◽

Cited By ~ 4

Author(s):

Chengxin Zheng ◽

Zhanyu Zhang ◽

Yunyu Wu ◽

Richwell Mwiya

Keyword(s):

Vertical Migration ◽

Growth Stage ◽

Nitrogen Leaching ◽

Water Saving ◽

Paddy Fields ◽

N Leaching ◽

Leaching Losses ◽

Leaching Loss ◽

Straw Return ◽

Percolation Water

The use of water-saving irrigation techniques has been encouraged in rice fields in response to irrigation water scarcity. Straw return is an important means of straw reuse. However, the environmental impact of this technology, e.g., nitrogen leaching loss, must be further explored. A two-year (2017–2018) experiment was conducted to investigate the vertical migration and leaching of nitrogen in paddy fields under water-saving and straw return conditions. Treatments included traditional flood irrigation (FI) and two water-saving irrigation regimes: rain-catching and controlled irrigation (RC-CI) and drought planting with straw mulching (DP-SM). RC-CI and DP-SM both significantly decreased the irrigation input compared with FI. RC-CI increased the rice yield by 8.23%~12.26%, while DP-SM decreased it by 8.98%~15.24% compared with FI. NH4+-N was the main form of the nitrogen leaching loss in percolation water, occupying 49.06%~50.97% of TN leaching losses. The NH4+-N and TN concentration showed a decreasing trend from top to bottom in soil water of 0~54 cm depth, while the concentration of NO3−-N presented the opposite behavior. The TN and NH4+-N concentrations in percolation water of RC-CI during most of the rice growth stage were the highest among treatments in both years, and DP-SM showed a trend of decreasing TN and NH4+-N concentrations. The NO3−-N concentrations in percolation water showed a regular pattern of DP-SM > RC-CI > FI during most of the rice growth stage. RC-CI and DP-SM remarkably reduced the amount of N leaching losses compared to FI as a result of the significant decrease of percolation water volumes. The tillering and jointing-booting stages were the two critical periods of N leaching (accounted for 74.85%~86.26% of N leaching losses). Great promotion potential of RC-CI and DP-SM exists in the lower reaches of the Yangtze River, China, and DP-SM needs to be further optimized.

Download Full-text

Effects of two wood-based biochars on the fate of added fertilizer nitrogen—a 15N tracing study

Biology and Fertility of Soils ◽

10.1007/s00374-020-01534-0 ◽

2021 ◽

Author(s):

Subin Kalu ◽

Gboyega Nathaniel Oyekoya ◽

Per Ambus ◽

Priit Tammeorg ◽

Asko Simojoki ◽

...

Keyword(s):

Plant Uptake ◽

Plant Biomass ◽

Application Rate ◽

Control Treatment ◽

Organic N ◽

N Leaching ◽

Soil N ◽

Mineral N ◽

Total N ◽

Application Rates

AbstractA 15N tracing pot experiment was conducted using two types of wood-based biochars: a regular biochar and a Kon-Tiki-produced nutrient-enriched biochar, at two application rates (1% and 5% (w/w)), in addition to a fertilizer only and a control treatment. Ryegrass was sown in pots, all of which except controls received 15N-labelled fertilizer as either 15NH4NO3 or NH415NO3. We quantified the effect of biochar application on soil N2O emissions, as well as the fate of fertilizer-derived ammonium (NH4+) and nitrate (NO3−) in terms of their leaching from the soil, uptake into plant biomass, and recovery in the soil. We found that application of biochars reduced soil mineral N leaching and N2O emissions. Similarly, the higher biochar application rate of 5% significantly increased aboveground ryegrass biomass yield. However, no differences in N2O emissions and ryegrass biomass yields were observed between regular and nutrient-enriched biochar treatments, although mineral N leaching tended to be lower in the nutrient-enriched biochar treatment than in the regular biochar treatment. The 15N analysis revealed that biochar application increased the plant uptake of added nitrate, but reduced the plant uptake of added ammonium compared to the fertilizer only treatment. Thus, the uptake of total N derived from added NH4NO3 fertilizer was not affected by the biochar addition, and cannot explain the increase in plant biomass in biochar treatments. Instead, the increased plant biomass at the higher biochar application rate was attributed to the enhanced uptake of N derived from soil. This suggests that the interactions between biochar and native soil organic N may be important determinants of the availability of soil N to plant growth.

Download Full-text

Relative contributions of different substrates to soil N2O emission and their responses to N addition in a temperate forest

The Science of The Total Environment ◽

10.1016/j.scitotenv.2020.144126 ◽

2021 ◽

pp. 144126

Author(s):

Bo Peng ◽

Jianfei Sun ◽

Jun Liu ◽

Zongwei Xia ◽

Weiwei Dai

Keyword(s):

Temperate Forest ◽

N2o Emission ◽

N Addition

Download Full-text

Effects of nitrogen and phosphorus additions on nitrous oxide emission in a nitrogen-rich and two nitrogen-limited tropical forests

Biogeosciences ◽

10.5194/bg-13-3503-2016 ◽

2016 ◽

Vol 13 (11) ◽

pp. 3503-3517 ◽

Cited By ~ 8

Author(s):

Mianhai Zheng ◽

Tao Zhang ◽

Lei Liu ◽

Weixing Zhu ◽

Wei Zhang ◽

...

Keyword(s):

Nitrous Oxide ◽

Tropical Forests ◽

N2o Emission ◽

N Deposition ◽

Soil N ◽

N Addition ◽

Old Growth ◽

Old Growth Forest ◽

P Addition ◽

Stimulation Of

Abstract. Nitrogen (N) deposition is generally considered to increase soil nitrous oxide (N2O) emission in N-rich forests. In many tropical forests, however, elevated N deposition has caused soil N enrichment and further phosphorus (P) deficiency, and the interaction of N and P to control soil N2O emission remains poorly understood, particularly in forests with different soil N status. In this study, we examined the effects of N and P additions on soil N2O emission in an N-rich old-growth forest and two N-limited younger forests (a mixed and a pine forest) in southern China to test the following hypotheses: (1) soil N2O emission is the highest in old-growth forest due to the N-rich soil; (2) N addition increases N2O emission more in the old-growth forest than in the two younger forests; (3) P addition decreases N2O emission more in the old-growth forest than in the two younger forests; and (4) P addition alleviates the stimulation of N2O emission by N addition. The following four treatments were established in each forest: Control, N addition (150 kg N ha−1 yr−1), P addition (150 kg P ha−1 yr−1), and NP addition (150 kg N ha−1 yr−1 plus 150 kg P ha−1 yr−1). From February 2007 to October 2009, monthly quantification of soil N2O emission was performed using static chamber and gas chromatography techniques. Mean N2O emission was shown to be significantly higher in the old-growth forest (13.9 ± 0.7 µg N2O-N m−2 h−1) than in the mixed (9.9 ± 0.4 µg N2O-N m−2 h−1) or pine (10.8 ± 0.5 µg N2O-N m−2 h−1) forests, with no significant difference between the latter two. N addition significantly increased N2O emission in the old-growth forest but not in the two younger forests. However, both P and NP addition had no significant effect on N2O emission in all three forests, suggesting that P addition alleviated the stimulation of N2O emission by N addition in the old-growth forest. Although P fertilization may alleviate the stimulated effects of atmospheric N deposition on N2O emission in N-rich forests, this effect may only occur under high N deposition and/or long-term P addition, and we suggest future investigations to definitively assess this management strategy and the importance of P in regulating N cycles from regional to global scales.

Download Full-text

Effect of Winter Cover Crops on Soil Nitrogen Availability, Corn Yield, and Nitrate Leaching

The Scientific World JOURNAL ◽

10.1100/tsw.2001.267 ◽

2001 ◽

Vol 1 ◽

pp. 22-29 ◽

Cited By ~ 19

Author(s):

S. Kuo ◽

B. Huang ◽

R. Bembenek

Keyword(s):

Cover Crops ◽

Cover Crop ◽

N Fertilizer ◽

N Leaching ◽

Corn Yield ◽

N Availability ◽

Soil N ◽

Soil N Availability ◽

N Concentration ◽

Fertilizer Rates

Biculture of nonlegumes and legumes could serve as cover crops for increasing main crop yield, while reducing NO3leaching. This study, conducted from 1994 to 1999, determined the effect of monocultured cereal rye (Secale cereale L.), annual ryegrass (Lolium multiflorum), and hairy vetch (Vicia villosa), and bicultured rye/vetch and ryegrass/vetch on N availability in soil, corn (Zea mays L.) yield, and NO3-N leaching in a silt loam soil. The field had been in corn and cover crop rotation since 1987. In addition to the cover crop treatments, there were four N fertilizer rates (0, 67, 134, and 201 kg N ha-1, referred to as N0, N1, N2, and N3, respectively) applied to corn. The experiment was a randomized split-block design with three replications for each treatment. Lysimeters were installed in 1987 at 0.75 m below the soil surface for leachate collection for the N0, N2, and N3treatments. The result showed that vetch monoculture had the most influence on soil N availability and corn yield, followed by the bicultures. Rye or ryegrass monoculture had either no effect or an adverse effect on corn yield and soil N availability. Leachate NO3-N concentration was highest where vetch cover crop was planted regardless of N rates, which suggests that N mineralization of vetch N continued well into the fall and winter. Leachate NO3-N concentration increased with increasing N fertilizer rates and exceeded the U.S. Environmental Protection Agency’s drinking water standard of 10 mg N l�1 even at recommended N rate for corn in this region (coastal Pacific Northwest). In comparisons of the average NO3-N concentration during the period of high N leaching, monocultured rye and ryegrass or bicultured rye/vetch and ryegrass/vetch very effectively decreased N leaching in 1998 with dry fall weather. The amount of N available for leaching (determined based on the presidedress nitrate test, the amount of N fertilizer applied, and N uptake) correlated well with average NO3-N during the high N leaching period for vetch cover crop treatment and for the control without the cover crops. The correlation, however, failed for other cover crops largely because of variable effectiveness of the cover crops in reducing NO3leaching during the 5 years of this study. Further research is needed to determine if relay cover crops planted into standing summer crops is a more appropriate approach than fall seeding in this region to gain sufficient growth of the cover crop by fall. Testing with other main crops that have earlier harvest dates than corn is also needed to further validate the effectiveness of the bicultures to increase soil N availability while protecting the water quality.

Download Full-text

Elevated CO2, but not defoliation, enhances N cycling and increases short-term soil N immobilization regardless of N addition in a semiarid grassland

Soil Biology and Biochemistry ◽

10.1016/j.soilbio.2011.07.017 ◽

2011 ◽

Vol 43 (11) ◽

pp. 2247-2256 ◽

Cited By ~ 6

Author(s):

Feike A. Dijkstra ◽

Gordon L. Hutchinson ◽

Jean D. Reeder ◽

Daniel R. LeCain ◽

Jack A. Morgan

Keyword(s):

Elevated Co2 ◽

N Cycling ◽

N Immobilization ◽

Soil N ◽

N Addition ◽

Short Term ◽

Semiarid Grassland

Download Full-text

Nitrate leaching and pasture production from different nitrogen sources on a shallow stoney soil under flood-irrigated dairy pasture

Soil Research ◽

10.1071/sr01015 ◽

2002 ◽

Vol 40 (2) ◽

pp. 317 ◽

Cited By ~ 70

Author(s):

H. J. Di ◽

K. C. Cameron

Keyword(s):

Nitrate Leaching ◽

Production Systems ◽

Environmental Concern ◽

Nitrogen Sources ◽

N Leaching ◽

Pasture Production ◽

Dairy Effluent ◽

Leaching Losses ◽

Rooting Zone ◽

Leaching Loss

The leaching of nitrate (NO3–) in intensive agricultural production systems, e.g. dairy pastures, is a major environmental concern in many countries. In this lysimeter study we determined the amount of NO3– leached following the application of urea, dairy effluent, urine returns, and pasture renovation to a freedraining Lismore stony silt loam (Udic Haplustept loamy skeletal) growing a mixture of perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) pasture. The study showed that NO3–-N leaching losses ranged from 112 to 162 kg N/ha per year, depending on the amount and forms of N applied and pasture conditions. Nitrate leaching under the urine patches was the main contributor to the N leaching loss in a grazed paddock. Nitrate leaching losses were lower for urine applied in the spring (29&percnt; of N applied) than for urine applied in the autumn (38–58&percnt;). The application of urea or dairy effluent only contributed a small proportion to the total NO3– leaching loss in a grazed paddock. Pasture renovation by direct-drilling may also have caused an increase in NO3– leaching (c. 31 kg N/ha) in the first year. Modelled annual average NO3–-N concentrations in the mixed recharge water in the acquifer were significantly lower than those measured under the rooting zone due to dilution effects by recharge water from other sources (3.9 v. 13–27 mg N/L). Herbage nitrogen offtake and dry matter yield were higher in the urine treatments than in the non-urine treatments. groundwater, denitrification, mineralisation, grazing, forage.

Download Full-text