Nitrate pollution in groundwater and strategies to reduce pollution

2002 ◽  
Vol 45 (9) ◽  
pp. 29-35 ◽  
Author(s):  
R.K. Shrestha ◽  
J.K. Ladah
Keyword(s):  
Cropping System ◽  
Sweet Pepper ◽  
World Health ◽  
Wet Season ◽  
Tropical Ecosystem ◽  
Mineral N ◽  
Use Efficiency ◽  
Low Levels ◽  
Indigofera Tinctoria ◽  
N Use

The input-intensive rainfed tropical ecosystem, where wet season (WS) rice (Oriza sativa L.) – dry season (DS) diversified high-value upland crops like vegetables predominate, has resulted in a problem of a large leakage of N into the environment, thereby polluting the water. Excessive use of N fertilizer in high-value crops grown in DS is economically motivated. Out of twenty water sources evaluated in a watershed with a total area of 265 ha located in Magnuang, Ilocos Norte, Philippines, twelve had near or above the World Health Organization’s (WHO) NO3-N limit for drinking water of 10 ppm. Soil mineral N (upper 100 cm) observed in seven rice-sweet pepper (Capsicum annuum L.) farmers’ fields ranged from 111 to 694 kg ha-1 which decreased by 10 to 68% in plots with dry-to-wet (DTW) crops like indigo, indigo+mungo and corn. In fallow plots where mineral N was either maintained or increased, it showed movement to lower soil profiles demonstrating NO3 leaching without a crop. On average, maize (Zea mays L.) captured 176 kg N ha-1 and indigo (Indigofera tinctoria L.) 194 kg N ha-1. In both fallow and planted plots, mineral N declined to low levels at 100% water-filled pore spaces (WFPS) before rice transplanting. A strategy for including indigo plus maize as a N-catch crop is proposed to decrease NO3 leaching and maximize N use efficiency in a rice-sweet pepper cropping system.

Response of soil N2 and N2O fluxes to denitrification control factors in two agricultural soils

2020 ◽  
Author(s):  
Amanda Matson ◽  
Stefan Burkart ◽  
Balazs Grosz ◽  
Jan Reent Köster ◽  
Simone Merl ◽  
...  
Keyword(s):  
Agricultural Soils ◽  
Integrated Control ◽  
Research Unit ◽  
Plant Residue ◽  
Mineral N ◽  
Control Factors ◽  
Biogeochemical Models ◽  
Flux Measurements ◽  
Use Efficiency ◽  
N Use

<p>Controlling soil N cycling to mitigate N-oxide emissions and optimize N use efficiency is an important aspect of agricultural soil management. Numerous denitrification models exist that can inform management decisions, but these are limited by the lack of soil N2 flux measurements to validate the model estimates. Measurements of soil denitrification - including both N<sub>2</sub>O and N<sub>2</sub> fluxes - are challenging, however, due to methodological limitations for the measurement of N<sub>2</sub> and the spatial/temporal heterogeneity of denitrification in soils.</p><p>We used laboratory incubations of re-packed soil cores, combined with both soil flushing and stable isotope techniques, to measure denitrification in two agricultural soils, as part of the DFG-research unit “Denitrification in Agricultural Soils: Integrated Control and Modelling at Various Scales (DASIM)”. The laboratory incubations used an automated mesocosm system, with regular measurements of both N<sub>2</sub>O and N<sub>2</sub>, to assess the response of soil denitrification to a variety of control factors. Control factors simulated typical scenarios that might occur in the field, including different amounts/types of plant residue, and changes in moisture, temperature, NO<sub>3</sub><sup>-</sup> and oxygen concentration. Both natural abundance and <sup>15</sup>N labeling of the soil mineral N pool were used to assess denitrification pathways.</p><p>Here we contrast the results of the incubation data from a sandy Podzol and silt-loam Luvisol. These data will be used to calibrate newly developed DASIM models as well as denitrification sub-modules of existing biogeochemical models. They will also inform the next steps of this work, which will extend the laboratory incubation technique to measure denitrification in undisturbed field soils.</p>

scholarly journals Experimental warming reduces fertilizer nitrogen use efficiency in a double rice cropping system

2019 ◽  
Vol 65 (No. 10) ◽  
pp. 483-489 ◽  
Author(s):  
Taotao Yang ◽  
Yanhua Zeng ◽  
Yanni Sun ◽  
Jun Zhang ◽  
Xueming Tan ◽  
...  
Keyword(s):  
N Uptake ◽  
Cropping System ◽  
Experimental Warming ◽  
Fertilizer N ◽  
Rice Season ◽  
Use Efficiency ◽  
Double Rice ◽  
Late Rice ◽  
N Use ◽  
Early Rice

Climate warming significantly affects nitrogen (N) cycling, while its effects on the use efficiency of fertilizer N are still unclear in agroecosystems. In the present study, we examined for the first time the response of fertilizer N use efficiency to experimental warming using <sup>15</sup>N labeling with a free-air temperature increase facility (infrared heaters) in a double rice cropping system. <sup>15</sup>N-urea was applied in micro-plots to trace the uptake and loss of fertilizer N. Results showed that moderate warming (i.e. an increase of 1.4°C and 2.1°C in canopy temperature for early and late rice, respectively) did not significantly affect grain yield and biomass. Warming significantly reduced N uptake from fertilizer for both early and late rice, while increased N uptake from soil. The N recovery rate of fertilizer was reduced from 35.5% in the control and to 32.3% in the warming treatments for early rice and from 47.2% to 43.1% for late rice, respectively. Warming did not affect fertilizer N loss rate in the early rice season, whereas significantly increased it from 38.9% in the control and to 42.7% in the warming treatments in the late rice season, respectively. Therefore, we suggest that climate warming may reduce fertilizer N use efficiency and increase N losses to the environment in the rice paddy.

Air warming and CO2 enrichment increase N use efficiency and decrease N surplus in a Chinese double rice cropping system

2020 ◽  
Vol 706 ◽  
pp. 136063 ◽  
Author(s):  
Bin Wang ◽  
Chen Guo ◽  
Yunfan Wan ◽  
Jianling Li ◽  
Xiaotang Ju ◽  
...  
Keyword(s):  
Co2 Enrichment ◽  
Cropping System ◽  
N Use Efficiency ◽  
Use Efficiency ◽  
Double Rice ◽  
N Use

scholarly journals Yield, nitrogen use efficiency and balance response to thirty-five years of fertilization in paddy rice-upland wheat cropping system

2019 ◽  
Vol 65 (No. 2) ◽  
pp. 55-62 ◽  
Author(s):  
Hu Cheng ◽  
Xia Xiange ◽  
Chen Yunfeng ◽  
Qiao Yan ◽  
Liu Donghai ◽  
...  
Keyword(s):  
Crop Yield ◽  
N Uptake ◽  
Cropping System ◽  
Mineral Fertilizer ◽  
Paddy Rice ◽  
N Use Efficiency ◽  
Soil N ◽  
N Input ◽  
Use Efficiency ◽  
N Use

Optimal soil nitrogen management is vital to crop production and environment protection. Little knowledge is available on crop yield, nitrogen uptake, use efficiency and balance in paddy rice-upland wheat cropping system of China. A thirty-five-year long-term field experiment was designed with nine treatments, including an unfertilized treatment (control), nitrogen (N), phosphorus (P), potassium (K) fertilizer, manure (M), and manure combined with mineral fertilizer treatments. Crop yield, N uptake, use efficiency, and N surplus or deficit amount were determined. The results indicated that rice, wheat yield and N uptake amount in the manure combined with mineral fertilizer treatments were higher than that in the manure alone or mineral fertilizer alone treatments. N use efficiency was the highest in the treatment with manure alone. Soil N input indicated a surplus in the mineral fertilizer in combination with manure treatment, but soil N input indicated a deficit in the control, NPK and M treatments. Considering crop yields, N use efficiency and N balance, recommended N application amount is almost 220 kg N/ha/year in the paddy rice-upland wheat cropping system. Taking into account labour and fertilizer sources, half mineral N and half organic N applications were recommended.

Mineral and slurry nitrogen effects on yield, N uptake, and apparent N-use efficiency of oilseed rape (Brassica napus)

1998 ◽  
Vol 130 (2) ◽  
pp. 165-172 ◽  
Author(s):  
K. SIELING ◽  
H. SCHRÖDER ◽  
H. HANUS
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Seed Yield ◽  
N Uptake ◽  
N Fertilization ◽  
N Use Efficiency ◽  
Pig Slurry ◽  
Mineral N ◽  
Use Efficiency ◽  
N Use

In NW Europe, autumn-grown oilseed rape normally receives nitrogen (N) in autumn as seedbed N and in the spring as a split application at the beginning of growth and at stem elongation. In the growing seasons 1990/91 to 1992/93, the effects of slurry and mineral N fertilization on yield, N uptake by the seed and apparent N-use efficiency (NUE) by oilseed rape (Brassica napus) were investigated in a factorial field experiment at Hohenschulen Experimental Station near Kiel, NW Germany. The crop rotation was oilseed rape–winter wheat–winter barley, and soil tillage (conservation tillage without ploughing, conventional tillage), application of pig slurry (none, autumn, spring, autumn+spring) and mineral N fertilization (0 to 200 kg N ha−1) were all varied. Each year, the treatments were applied to all three crops of the rotation and were located on the same plots.Between the years, average seed yield ranged from 3·04 to 3·78 t ha−1, while the corresponding N uptake by the seed varied from 107 to 131 kg N ha−1. Slurry application in spring increased the seed yield and N uptake by the seed in all years, whereas the effect of autumn slurry alone or in combination with spring slurry was negligible. Mineral N fertilizer increased seed yield and N uptake by the seeds except in 1991/92, when N amounts exceeded 160 kg N ha−1. No significant slurry×mineral N interaction occurred. Apparent NUE of mineral N was larger than that of slurry N, but decreased with increasing mineral fertilizer N rates. Only 5% of the autumn slurry N was apparently utilized by the seeds, compared with 24% of the spring slurry N.Despite its ability to take up substantial quantities of N before the winter, oilseed rape utilized very little autumn slurry N for seed production. To minimize environmental impacts, slurry should be applied in the spring, when plants are more able to use N for yield formation, even if NUE of slurry N is lower than that of mineral N. However, since NUE changes with the amount of applied N, it is difficult to find the best combination of slurry and mineral N fertilization to avoid negative environmental effects.

GROUNDWATER DYNAMICS AND QUALITY UNDER INTENSIVE CROPPING SYSTEMS

1999 ◽  
Vol 35 (2) ◽  
pp. 153-166 ◽  
Author(s):  
R. J. GUMTANG ◽  
M. F. PAMPOLINO ◽  
T. P. TUONG ◽  
D. BUCAO
Keyword(s):  
Nitrogen Fertilizer ◽  
Management Practices ◽  
Cropping Systems ◽  
Sweet Pepper ◽  
Service Area ◽  
World Health ◽  
Wet Season ◽  
Groundwater Dynamics ◽  
The Mean ◽  
Health Organization

A study was conducted from October 1994 to March 1996 to assess groundwater dynamics and quality in relation to landuse and farm input of nitrogen fertilizer in a highly diversified and intensive agricultural area at Magnuang, Batac, Ilocos Norte. Monthly groundwater depths, nitrate-nitrogen (NO3-N), chloride (Cl−), bicarbonate (HCO3−), electrical conductivity (EC) and pH were determined in 19 agricultural and domestic wells. In the dry season, sweet pepper (Capsicum annuum) had a higher irrigation requirement and caused more groundwater level decline than other crops. EC (700–3000 μmho cm−1) and HCO3− (90–500 ppm) in all wells exceeded the FAO threshold quality for irrigation but were not related to farm management practices. Eight wells showed near or above the World Health Organization NO3-N limit (10 ppm) for drinking water. High nitrogen fertilizer input increased the mean NO3-N (r2 = 0.45, p < 0.002). The percentage of the wells' service area under rice cultivation in the wet season accounted for 84% (p < 0.001) of the variation in NO3-N among the wells. The mean NO3-N declined as the percentage of service area under rice increased. This was related to the denitrification process in the flooded fields and the lower levels of nitrogen fertilizer for rice compared with other crops.

Growth stage-specific application of slurry and mineral N to oilseed rape, wheat and barley

2004 ◽  
Vol 142 (5) ◽  
pp. 495-502 ◽  
Author(s):  
K. SIELING
Keyword(s):  
Oilseed Rape ◽  
N Fertilizer ◽  
N Use Efficiency ◽  
Yield Potential ◽  
Soil Conditions ◽  
Pig Slurry ◽  
Mineral N ◽  
Significant Difference ◽  
Use Efficiency ◽  
N Use

Farmers commonly apply slurry when soil conditions are suitable for spreading. In order to improve slurry nitrogen (N) use efficiency, effects of split application of pig slurry according to the crop N demand on yield were tested in 1994/95–2001/02. The crop rotation was winter oilseed rape (OSR) – winter wheat – winter barley. N was applied as pig slurry or as mineral N fertilizer (each of 0, 40 or 80 kg N/ha, total N amount: 0–240 kg N/ha) at three dates. Each year, the treatments occurred in all three crops of the rotation and were located on the same plots. On average, mineral N fertilizer led to higher grain yields in all crops (+0·33 t/ha in OSR, +0·57 t/ha in wheat, and +0·20 t/ha in barley) compared with slurry application, presumably due to a slower N mineralization of the organic fraction. However, the large year to year variation resulted in high error estimates, leading to no significant differences in yield. Taking only the ammonium amount of the slurry into account, there was no significant difference in yield between the two N sources. Yield potential was similar in both slurry and mineral N treatments, but higher N amounts were necessary on the slurry plots. Therefore, slurry N-use efficiency (NUE) remained lower than that of mineral N. However, compared with a single dose, growth-specific slurry application according to the crop demand, as made with mineral N fertilizers, increased NUE.

Yield, N uptake, and apparent N-use efficiency of winter wheat and winter barley grown in different cropping systems

1998 ◽  
Vol 131 (4) ◽  
pp. 375-387 ◽  
Author(s):  
K. SIELING ◽  
H. SCHRÖDER ◽  
M. FINCK ◽  
H. HANUS
Keyword(s):  
Winter Wheat ◽  
N Uptake ◽  
Wheat Yield ◽  
Mineral Fertilizer ◽  
N Fertilization ◽  
N Use Efficiency ◽  
Fertilizer N ◽  
Mineral N ◽  
Use Efficiency ◽  
N Use

Increasing the efficiency with which crops use supplied nitrogen (N) can minimize the impact on the environment. In the growing seasons 1990/91 to 1992/93, the effects of different cropping systems on yield, N uptake by the grain and apparent N-use efficiency (NUE) of the grain of winter wheat and winter barley were investigated in a factorial field experiment at Hohenschulen Experimental Station near Kiel in NW Germany. The crop rotation was oilseed rape–winter wheat–winter barley, and soil tillage (conservation tillage without ploughing, conventional tillage), application of pig slurry (none, autumn, spring, autumn+spring), mineral N fertilization (0–240 kg N ha−1) and application of fungicides (none, applications against pathogens of the stems, leaves and ears) were all varied. Each year, the treatments were applied to all three crops of the rotation and were located on the same plots.Averaged over all factors, wheat yield was >7 t ha−1 dry matter in all years and N uptake of the harvested grain varied between 140 and 168 kg N ha−1. Pig slurry application in autumn increased grain yield and N uptake more than spring slurry in two out of three years. Mineral N unfertilized wheat yielded only 5·3–6·3 t ha−1 depending on the year, mineral N fertilization increased wheat yield up to 8 t ha−1. Barley yield was lower than wheat yield, ranging from 4·5 t ha−1 in 1993 to 6·3 t ha−1 in 1992. Unlike wheat, spring slurry N affected barley yield and N uptake more than autumn slurry.Wheat apparently utilized 12–21% and barley up to 13% of the applied slurry N for its grain development. In 1991, the highest apparent slurry N-use efficiency (SNUE) of wheat and barley occurred after the late spring slurry application. However, in the following years, autumn SNUE of wheat was similar to (1992) or higher than (1993) spring SNUE, presumably because of vigorous tiller growth before winter. Additionally applied mineral fertilizer N decreased SNUE.Apparent mineral fertilizer N-use efficiency (FNUE) was higher than SNUE and ranged in wheat from 40 to 59% and in barley between 19 and 37% of the applied mineral fertilizer N. FNUE decreased with increasing N fertilization.To improve the N-use efficiency of both slurry N and mineral fertilizer N, more information is needed about the combined use of both N sources, with special emphasis on split applications of slurry as is common practice for mineral N fertilizer.

scholarly journals Biochar Integration with Legume Crops in Summer Gape Synergizes Nitrogen Use Efficiency and Enhance Maize Yield

Agronomy ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 58 ◽  
Author(s):  
Fazal Jalal ◽  
Muhammad Arif ◽  
Kashif Akhtar ◽  
Aziz Khan ◽  
Misbah Naz ◽  
...  
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
N Use Efficiency ◽  
Mineral Fertilizers ◽  
Cropping Pattern ◽  
Above Ground Biomass ◽  
Mineral N ◽  
Ground Biomass ◽  
Use Efficiency ◽  
N Use

Besides carbon (C) sequestration, biochar (BC) is recently believed to deliver multiple eco-friendly benefits to the soil for enhancing crop productivity. Use of mineral fertilizers coupled with BC been suggested a promising sustainable strategy for increasing crops yield. However, imperative study is needed to investigate (1) BC integration with multiple legumes crop adjusted in summer gape for pooling more organic carbon and nitrogen, and (2) subsequently looking into its synergism with mineral N in the following crop. Therefore, two years’ field experiments were conducted on maize under cereal based cropping pattern with the adjustment of legumes (i.e., mungbean, cowpea, and Sesbania) with a fallow in summer. In legumes, treatments consist of (0 and 50 t ha−1) BC application. However, N rates of 0, 90, 120, 150 kg ha−1 were added to the subsequent maize crop. Preceding legumes plots with the use of 50 t ha−1 biochar enhanced maize grain yield, above ground biomass, stover N, grain N, soil C, and N content after maize harvest and N use efficiency as compared to non-legumes with BC and legumes without BC plots. N application increased grain yield, above-ground biomass, stover N, grain N, and soil N but reduced N use efficiency with higher rates. Conclusively, the integration of biochar and legumes is a promising option for increasing the entire farm production of cereal-based cropping systems. This increment in yield was associated with supplying a viable input of N and C to soil and increased yields from this supplementary ‘summer gap’ crop.

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