Nitrogen Outflow Research Articles

Model of nitrogen management on farms specializing in livestock production

Abstract The aim of this study was to determine the relationship between the efficiency of agricultural production and selected parameters of farms and data describing the flow of nutrients on the farms. An analysis model was developed for nitrogen management on farms specializing in livestock production. The study was conducted on 20 farms located in 12 municipalities of the Mazowieckie province in central Poland in 2009.2012. The model was developed using multiple linear regression analysis in accordance with the backward stepwise method. Based on the regression analysis, the farm parameters that did not determine the dependent variable were eliminated. In the end, there were 10 independent variables included in the model. The model indicates that the efficiency of nitrogen management, expressed in cereal units per 1 kg of nitrogen (CU·kg-1 N), is significantly affected by: crop rotation, the demand for purchasing animal feed, the intensity of livestock production, the nitrogen content of farmyard manure, the nitrogen doses applied in mineral and natural fertilizers, and nitrogen outflow from farms with the sale of plant and animal products. The developed model explains 70% of the variation in the coefficient of efficiency expressed in cereal units per 1 kg N.

Changes in the nitrogen balance in agricultural land in Japan and 12 other Asian Countries based on a nitrogen-flow model

Gross and per unit agricultural land area nitrogen balance (NB G and NB A, respectively) in agricultural areas were estimated with a nitrogen-flow model for 13 Asian countries, for regions within a country, and for individual grid cells, from 1970 to 2005. Country- and regional-level estimates showed that NB A is higher in Japan and South Korea than in other Asian countries, but has recently been stable or decreasing. The contribution of inorganic fertilizer to the nitrogen input is decreasing, whereas that of livestock manure is increasing in these countries. In many other countries, the primary nitrogen source is inorganic fertilizer and its input rate and NB A have increased sharply since the 1980s. NB A of some Chinese provinces and Indian states were as high as those of Japan and South Korea. The results suggest that regional-scale estimation is necessary because of the large spatial variability in nitrogen flows within a country. Based on the NB G estimated for each 0.5° × 0.5° grid cell, nitrogen outflow from agriculture into major river basins was evaluated. About 20 % of the nitrogen balance flowed into China’s Changjiang River basin, versus 10 % into the Ganges River basin. Uncertainties in the basic data and estimation results, and the use of an alternative measure of a country’s environmental performance were discussed.

Investigation into the durability of washed rice straw for equine bedding and the repetitive use of washing water

The present experiment investigated durability during the repetitive use of washed rice straw, as bedding material, and washing water as a model study. Residual nitrogen levels, elasticity, and water suction rates for washed rice straw-adhered urea were measured. In addition, outflow levels of nitrogen and mineral ions (Na(+), NO(2)(-) + NO(3)(-), SO(4)(2-), PO(4)(3-), Cl(-)) for washing water were measured to determine durability. Nitrogen levels of rice straw significantly (P<0.05) decreased after two washings. There was no significant change in elasticity of repetitively used rice straw. Suction rates of rice straw after the second and third washings increased significantly (P<0.05) compared to the first time. With regard to the number of washings, the mineral ion outflow level in the washing water for nitrogen, Na(+), NO(2)(-) + NO(3)(-) and PO(4)(3-) after each washing was not significant. However, nitrogen outflow level tended to decrease after the third washing. SO(4)(-) and Cl(-) did significantly decrease (P<0.05) with the number of washings. In this study, it was considered that rice straw and washing water could be used repetitively three times. Furthermore, in order to maintain effluent standards, washing water from the first washing needs to be processed in a septic tank.

충남 고성천 유역의 하천 수질 평가를 이용한 유역단위 질소와 인 수지 분석

This study was conducted to assess the impact of agricultural land use on the water quality in mountain village farmlands. Two soil types, paddy and upland soil were analysed for their chemical properties. Although, pH and organic matter contents were not significantly different to each other, concentrations of available P and exchangeable K and Ca were much higher in upland soil compared with those in paddy soil. The results of water quality analysis indicated that, in Goseong-cheon watershed, the nutrients contents were much higher in downstream area than in upstream area. Particularly, the elevation of and T-P were significant during rainy season. When paddy fields coexist with upland fields, SS, T-N, and T-P concentrations in paddy fields were lower than those of upland fields. This may indicate that paddy fields possess an water-purifying ability by absorbing nutrients. This effect may reduce excessive nutrients discharged into the neighboring streams which may cause eutrophication problem. The difference between inflow and outflow of nitrogen and phosphorus during the cultivation period were measured as -98.9 kg and -29.7 kg , which means that nutrient outflow was higher than inflow. This may suggest that much nutrient was discharged during the crop harvest period.

Abstracts of Nippon Dojo-Hiryogaku Zasshi

Abstracts of Nippon Dojo-Hiryogaku Zasshi

Study of heat exchange during discharge of cryogenic products into water

With the aim of clarifying conditions for dangerous discharge of cryogenic fuels into water in a test unit heat exchange in the area of the discharge pipe, evaporation and heating of vapors during their movement in water are studied. It is established that with continuous outflow of liquid nitrogen into water through fittings made of different materials in regimes that are possible in a real system the continuous shearing of ice due to the hydrodynamic thrust of the flow provides independence of the average flow rate on parameters of the emerging product, but it depends to a considerable degree on orientation of the flow. Calculated results are provided for emergence of liquid hydrogen during which with discharge from an industrial system into sea water there may be formation of an incendiary cloud.

Evaluation of the implementation of a goal-oriented peatland rehabilitation plan

Ecological restoration is a problem-driven scientific discipline. Thus an evaluation of the restoration strategies is needed periodically to improve the concepts. In Northern Germany, the Environmental Ministry adopted a peatland action plan in 2002 with the goal to (I) rehabilitate the water quality improvement potential of degraded peatlands and (II) to create suitable habitat conditions for endangered wetland species. The plan is implemented in a series of stages. The goals are clearly stated in the plan. For state-wide site selection, a GIS-based peatland information system was developed. For each peatland, information about land use, hydrology, conservation status, species occurrence and soil is stored in the database. Peatland sites with a high risk for nitrogen leaching are identified by calculating a land use intensity index. A flow path-oriented decision support system was developed to calculate the effect of land use and water management changes on nitrogen outflow and nitrogen transformation. The model result – absolute reduction of nitrogen outflow – is transformed into a cost-effectiveness value, which is used by water authorities to rank funding proposals. The DSS is developed as user-friendly, web-based software; its handling requires basic knowledge of landscape hydrology. However, local authorities do not use both tools intensively. For them, the most important factor for site selection is the possibility of land acquisition. To improve goal-oriented site selection and planning, local authorities need more training and a better hydrological understanding. To improve the effectiveness of ecological restoration projects, training and capacity building are as important as tool development and research.

Runoff nitrogen from a large sized paddy field during a crop period

Nutrient load management is an important environmental issue because nutrient loads from farmlands degrade surface waters as a result of anthropogenic eutrophication. Nitrogen load from a large sized paddy field during the crop period was examined from the results of field measurements carried out in 2004. The 1.5 ha paddy field was located east of Biwa Lake. Irrigation water volume and ponded water depth were continuously observed. Field measurements were carried out at least once a week to analyze total nitrogen (TN) concentration in the irrigation water and ponded water. Daily inflow and outflow of nitrogen was obtained by multiplication of the nitrogen concentration and transported water volume, consisting of irrigation, precipitation, evapotranspiration, percolation and surface discharge. Water outflow volume was calculated by a tank model that consisted of three small tanks connected to represent ponded water depth differences in the large paddy field. The calculated nitrogen load was 18.8 kg ha −1, with 7.2 kg ha −1 from surface drainage and 11.6 kg ha −1 from percolation loss. The runoff nitrogen value of 18.8 kg ha −1 was within the range of the reported values investigated in a medium-sized paddy field. The observed value was close to the value for a low percolation flux paddy field where less irrigation water has been applied. These results suggest that less irrigation water keep runoff nitrogen low. This also indicates that irrigation water management can reduce nitrogen load from large sized paddy fields.

Total nitrogen inflow and outflow from a large river swamp basin to the Gulf of Mexico

River corridor wetland restoration and freshwater diversion from the lower Mississippi River are being considered as two major options to reduce nitrogen input to the Gulf of Mexico. However, it is largely uncertain how much nitrogen can actually be retained from the overflowing waters by these wetland systems. This study quantified the nitrogen inflow and outflow for the largest distributary basin of the Mississippi River, the Atchafalaya River Swamp basin. The goal of the study was to seek answers to three critical questions: (a) Does the Atchafalaya River Swamp remove a significant amount of nitrogen from the overflowing water, or is it releasing more nitrogen into the Gulf? (b) How do the nitrogen removal or release rates fluctuate seasonally and annually? (c) What are the relationships between the nitrogen removal capacity and the hydrological conditions in the basin such as river stage and discharge? By utilizing the long-term (1978–2002) river discharge and water quality data, monthly and annual nitrogen fluxes were quantified, and their relationships with the basin hydrological conditions investigated. A total nitrogen—sum of the total Kjeldahl nitrogen (TKN) and nitrate plus nitrite nitrogen (NO3+NO2)—mass input—output balance between the upstream (Simmesport) and downstream (Morgan City and Wax Lake Outlet) locations was established to examine the nitrogen removal potential for this, the largest freshwater swamp basin in North America. The results from this study showed that, over the past 25 years, the Atchafalaya River Swamp basin acted as a source for NO3+NO2 nitrogen, although the average annual output of NO3+NO2 nitrogen (174 584 Mg) was only slightly higher (2.3%) than the average annual input of NO3+NO2 nitrogen (170 721 Mg). The higher NO3+NO2 mass outflow occurred throughout summer and autumn, indicating an active role of biological processes on nitrogen in the overflowing waters of the Atchafalaya. However, this swamp basin has served as a major sink for organic nitrogen: the annual averages of TKN mass input and output were 200 323 and 145 917 Mg year−1, respectively, presenting a 27.2% removal rate by the basin. This large TKN reduction appeared high during springs and low during late summers, corresponding with the fluctuation of the hydrological conditions of the river.

Economic valuation of reduction in nitrogen outflow from a paddy field area equipped with a recycling irrigation facility

We estimated the reduction in nitrogen outflow load from a paddy field that had a recycling irrigation facility and, by using a replacement cost method, evaluated the economic effect of nitrogen removal by the paddy field during the irrigation period in the Yoshinuma region of Tsukuba City, Japan. The recycling ratio of outflow water (proportion of outflow reused) was 13.5%. The nitrogen (N) outflow load was reduced by about 45 kg ha(-1) by the N removal function of the paddy field and by about 39 kg ha(-1) by the recycling irrigation facility. The paddy field equipped with a recycling irrigation facility as an N removal facility was valued at 32.6 million Japanese yen (JPY) ha(-1) and 0.72 million JPY ha(-1) per year, which compare it with the construction and maintenance costs, respectively, of a water quality improvement facility. The recycling irrigation facility was costed at 17.3 million JPY ha(-1) for construction and 0.21 million JPY ha(-1) for maintenance per year. The cost for constructing and maintaining a recycling irrigation facility was 53% of the value of the paddy field area equipped with a recycling irrigation facility as an N removal facility.

Methods for Estimating the Nitrogen Load on a Catchment Scale

A Windows-based system for estimating the potential nitrogen (N) outflow in a catchment has been developed. The system includes a conversion method for administrative-based data from national scale statistics, such as the agricultural census, into a catchment-based data by utilizing the geographic information system (GIS). The system calculates N loads based on the pollutant load unit (PLU) method in a catchment and converts them to potential N outflows by introducing the outflow coefficients. For the catchments of tributaries flowing into Lake Kasumigaura in central Japan, where non-point sources were predominant, the N loads and the potential N outflows from 1950 to 1995 were estimated. The actual N outflows from the tributaries were also estimated using the water quality monitoring data at the outlet of the tributary catchment and meteorological data. These potential N outflows and actual N outflows were compared. Results obtained were as follows. (i) Some estimates by the present method, such as the drainage area and cultivation areas of various crops in each tributary, well agreed with those estimated by other methods and published data, indicating that this method was capable of estimating catchment-based data from the administrative-based statistics. (ii) Changes in the potential outflows during the period from 1950 to 1995 reflected the changes in livestock production and methods of waste water treatments. (iii) Comparison between the N potential outflows and the actual N outflows suggested that about 47% of the generated N load which leached down to groundwater from the soil surface flowed out and that a time-lag between two outflows appeared. Thus, the developed system offered good possibilities of realistic quantitative analyses on the contribution of non-point sources to water quality on the scale of a catchment.

Nitrogen Outflow to Groundwater and its Control in Sub-tropic Islands

Nitrogen Outflow to Groundwater and its Control in Sub-tropic Islands

벼농사에서 질소유출이 수질에 미치는 영향평가

It is important to understand and evaluate the environmental impacts of rice cultivation for developing environmentally-friendly agriculture because rice is main crop in Korea and rice cultivation have both functions of water pollution and purification with environmental and cultivation conditions. This paper presents the evaluation of nitrogen impact by rice cultivation on water system. A simple protocol was proposed to assess the potential amount of nitrogen outflow from paddy field and most of parameters affect on the nitrogen outflow from paddy field such as the amount of fertilizer application, water balance, the quality and quantity of irrigation water, soil properties, nitrogen turnover in the soil and cultivation method were considered. To develop the protocol, coefficients for parameters affected nitrogen turnover and outflow were gotten and summarized by comparison and analysis of all possible references related, and by additional experiments at field and laboratory. And potential amount of nitrogen input and output by water in paddy field were estimated with the protocol at the conditions of the nitrogen contents of irrigation water, amount of fertilizer application, and irrigation methods. Where irrigation water was clean, below 1.0 mg of nitrogen concentration, rice cultivation polluted nearby watershed. At the conditions of 2.0 mg of nitrogen concentration, 110 kg of nitrogen fertilizer application and flooding irrigation, rice cultivation had water pollution function, but it had water purification function with intermittent irrigation. At the conditions of 3.0 mg of nitrogen concentration and 110 kg of nitrogen fertilizer application, rice cultivation had water purification function, but that had water pollution function with 120 kg of nitrogen application. Where irrigation water was polluted over 6.0 mg of nitrogen, it was evaluated that rice cultivation had water purifying effect, even though the amount of nitrogen application was 120 kg .

Rice straw degradation and biomass synthesis by rumen micro-organisms in continuous culture in response to ammonia treatment and legume extract supplementation

The effects of ammonia treatment and fresh legume extract supplementation on the metabolism of rumen micro-organisms maintained on rice straw ( Oryza sativa, variety Thaibonnet) in dual outflow fermenteurs were investigated. Alfalfa ( Medicago sativa L.) was chosen as a model legume, similar in biochemical composition to cowpea ( Vigna unguiculata). Diets provided comparable amounts of readily available N. The interaction between ammonia treatment and legume extract supplementation was generally negligible. The relative productions of VFA (in moles/100 moles of hexoses fermented) were oriented to an increased proportion of C4 to the detriment of C2 by ammonia pre-treatment (+100% versus −28% at the intermediate extract input level), which also lowered the relative production of CH 4 by 36%. The true degradability of organic matter (OM) was 27% higher with treated rice straw (TRS) than with untreated rice straw (URS). The degradabilities of ash-free neutral detergent fibre (NDF) and acid detergent fibre (ADF) ranged from 30 to 50% and from 26 to 48%, respectively. At low levels of extract supplementation, the degradabilities of ash-free NDF and ADF tended to be lower with TRS than with URS (30% versus 46% in the case of ADF), while at high levels of the alfalfa extract they were not modified by straw pre-treatment. The outflow of non-ammonia nitrogen (NAN) was higher with TRS (+41% at the intermediate legume input rate). This increased NAN outflow was essentially of microbial origin. Alfalfa extract supplementation also increased net production of microbial protein. The efficiency of microbial protein synthesis was strongly increased by ammonia pre-treatment and by extract supplementation, in a linear manner. Both treatments were beneficial to rumen microbial metabolism in vitro, while acting independently on microbial functions. Ammonia treatment induced the most significant changes, especially in favouring extensive biomass synthesis.

Nitrogen Outflow and its Variance After Rainfall Events From the Watershed with Pig Farms

Nitrogen Outflow and its Variance After Rainfall Events From the Watershed with Pig Farms

Mud shrimp burrows as dynamic traps and processors of tidal-flat materials

Bacterial abundance, electron transport system activity (ETSA) and organic matter con- tent (total organic carbon (TOC), total nitrogen (TN) and chl a) on the burrow wall of the mud shrimp Upogebia major were determined and compared with those in surrounding non-burrow sediments and on the tidal-flat surface. The values of each parameter in burrow sediment tended to decrease outwardly from the wall, while bacteria abundance was highest in the subsurface of the burrow wall. In summer, the abundance of bacteria on the burrow wall was double that in the non-burrow sediments. In winter, both bacterial abundance and ETSA were at the same level as those in non- burrow sediments. The levels of TOC and TN on the burrow wall were more than 3 times higher than those in non-burrow sediments, regardless of the season. However, there was no significant difference in chl a content between burrow wall and non-burrow sediments. These results suggest that fresh organic matter in the burrow wall is supplied from the tidal-flat surface, making the burrow environment a suitable niche for microbial populations in the sediment. The mud shrimp burrow functions as a trap for organic matter and thus, helps prevent the outflow of carbon and nitrogen from the tidal flat.

Nutrient flows and management of a small watershed

Nutrient leaching from agricultural areas is one of the main concerns of watershed management. The paper examines nitrogen and phosphorus leaching from different parts of small agricultural watershed (378 ha) that was divided into 6 subcatchments. The calculations of nutrient outflow are based on the detailed measurement at the time of intensive agricultural activities during 5 years (1987–1991). The results show that nutrient leaching can vary very much even in such a small catchment area. The retention of nitrogen and phosphorus took place in the storage lake: 3,900 and 2.2 kg ha−1 year−1, respectively. At the same time, in the small subcatchment with high shallow groundwater outflow value, the nitrogen and phosphorus outflow was 233 and 0.90 kg ha−1 year−1, respectively. The most effective mitigation method is establishing buffer zones on the banks of the stream. A buffer zone of 460 m length would remove 2,200 to 2,640 kg N and 12 to 15 kg P a year, a constructed wetland on the stream would remove 1,660 to 2,760 kg N and 3 to 4.5 kg P a year. The detailed study gives good opportunity to estimate most critical areas where application of mitigation methods is most needed and ecologically and economically effective.

Modelling Nitrogen Cycling in a Mariculture Ecosystem as a Tool to Evaluate its Outflow

A model was constructed to describe an intensive mariculture ecosystem growing sea bass (Dicentrarchus labrax), located in the salt marshes of the Fiers d'Ars Bay on the French Atlantic coast, in order to assess nitrogen cycling within the system and nitrogen outflow from the system. The land-based system was separated into three main compartments: a seawater reservoir, fish ponds and a lagoon (sedimentation pond). Three submodels were built for simulation purposes: (1) a hydrological submodel which simulated water exchange; (2) a fish growth and excretion bioenergetic submodel; and (3) a nitrogen compound transformation and loss submodel (i.e. ammonification, nitrification and assimilation processes). A two-year sampling period of nitrogen water quality concentrations and fish growth was used to validate the model.The model fitted the observations of dissolved nitrogen components, fish growth and water fluxes on a daily basis in all the compartments. The dissolved inorganic nitrogen ranged widely and over time from 0·5 to 9gNm−3within the system, depending on seawater supply and water temperature, without affecting fish growth. Fish feed was the most important input of nitrogen into the system. The mean average input of nitrogen in the feed was 205kgNday−1, of which 19% was retained by fish, 4% accumulated in the sediment and 61% flowed from the system as dissolved components. The farm represented about 25% of the total dissolved nitrogen export from the bay, although the farm surface area was 100 times smaller than that of the bay.

Characteristics of Nitrogen Outflow from a High Stocking Density Are

Characteristics of Nitrogen Outflow from a High Stocking Density Are

Research on Nitrogen Outflow from a High Stocking Area

Research on Nitrogen Outflow from a High Stocking Area