Farm Gate Balance Research Articles

Comparison of regulatory approaches for determining application limits for nitrogen fertilizer use in Germany

This study examined the suitability of three different indicators as entry points for agricultural regulation for limiting excess nitrogen (N) fertilizer inputs in Germany: net soil surface balance, gross farm-gate balance, and fertilization planning. Data on about 6000 farms in Germany were grouped into types for comparative analysis. The design of the regulatory approaches and the reliability of constituent parameters were then examined, and proportions of affected farms and mean N reduction requirements were identified. This revealed that: (a) design and purpose of the regulatory approaches differ, but the data requirements are very similar; (b) the parameters involved differ in reliability and integrity; and (c) the limits for maximum N fertilizer input at farm level vary with approach and farm type.

Generating applicable environmental knowledge among farmers: experiences from two regions in Poland

ABSTRACTRaising environmental awareness among farmers is the key to successfully reaching environmental goals. The present study assessed the knowledge development process and the raising of environmental awareness among 30 farmers from Poland exposed to four approaches aimed to reduce phosphorus (P) and nitrogen (N) losses to water. The farmers were interviewed with open-ended questions on-farm both before and after the project intervention. As hoped, the farmers attempted to adjust their farm practices to the European Union regulations, which are in some cases supported by subsidies. As a complement, the project offered tools for system-thinking based on farm data and support from agricultural advisors: a) a survey of plant-available P, potassium (K), magnesium (Mg), and soil pH, resulting in soil maps; b) assessment of nitrogen leaching risks from individual fields; c) compilation of a farm-gate balance. Farmers were positive to soil surveys and maps, but had limited understanding of the nutrient balance concept and calculations. They generally relied on their own experiences regarding fertilization rather than on calculated farm nutrient balances and leaching risks. Farmers’ understanding and willingness to adopt new approaches to improve nutrient efficiency and reduce negative environmental impacts are discussed.

Direct and Indirect Economic Incentives to Mitigate Nitrogen Surpluses: A Sensitivity Analysis

The reduction of nitrogen (N) surplus is an ongoing topic in the agri-environmental policies of many countries in the developed world. The introduction of N balance estimation in agricultural sector models is therefore pertinent and requires an interdisciplinary approach. We extended the agent based agricultural sector model SWISSland with an N farm gate balance estimation to pre-evaluate the introduction of a levy on N inputs, particularly a levy on fertilizer and imported concentrates, on N surplus reduction in the Swiss agriculture. The model was based on the Swiss farm accountancy data network (FADN) for 3,000 farms. The model’s ability to represent the N balance was assessed by conducting a structured full factorial sensitivity analysis. The sensitivity analysis revealed the possibility to switch to organic farming and the hectare based payments for ensuring food security as key parameters with the largest influence on the modelled N surplus. The evaluation of N input levy scenarios suggested that an introduction of a tax of 800% of N price will reduce the N surplus by 10% indicating a price elasticity of -0.03. The sensitivity analysis and the results from the levy scenarios suggest that indirect instruments, such as optimizing the direct payments scheme, should be considered rather than direct instruments for an effective N surpluses mitigation in Swiss agriculture.

Tools for evaluating and regulating nitrogen impacts in livestock farming systems

This article describes several indicators and methods for estimating nitrogen flows and balance sheets. It reviews their strengths and weaknesses according to user types and their objectives. The nitrogen balance sheets, based on the difference between inputs and outputs are by far the most-often used estimator of nitrogen management on livestock farms. Among those, the soil surface balance helps in guiding the fertilisation and the farmgate balance is logically higher. The indicators of practices are easy to use but are poor predictors of nitrogen losses, whereas the indicators of emissions allow for estimating nitrogen losses using either direct measurements or models thereby providing a dynamic assessment of these flows. The coupling of balance sheets and indicators of emissions offers a certain potential for improvement of diagnosis and support of decision making. Finally, the indicators of impacts, including the life cycle analyses are currently the most popular for qualifying the impacts of animal production.

Mixed crop-livestock systems: an economic and environmental-friendly way of farming?

Intensification and specialisation of agriculture in developed countries enabled productivity to be improved but had detrimental impacts on the environment and threatened the economic viability of a huge number of farms. The combination of livestock and crops, which was very common in the past, is assumed to be a viable alternative to specialised livestock or cropping systems. Mixed crop-livestock systems can improve nutrient cycling while reducing chemical inputs and generate economies of scope at farm level. Most assumptions underlying these views are based on theoretical and experimental evidence. Very few assessments of their environmental and economic advantages have nevertheless been undertaken in real-world farming conditions. In this paper, we present a comparative assessment of the environmental and economic performances of mixed crop-livestock farms v. specialised farms among the farm population of the French ‘Coteaux de Gascogne’. In this hilly region, half of the farms currently use a mixed crop-livestock system including beef cattle and cash crops, the remaining farms being specialised in either crops or cattle. Data were collected through an exhaustive survey of farms located in our study area. The economic performances of farming systems were assessed on 48 farms on the basis of (i) overall gross margin, (ii) production costs and (iii) analysis of the sensitivity of gross margins to fluctuations in the price of inputs and outputs. The environmental dimension was analysed through (i) characterisation of farmers’ crop management practices, (ii) analysis of farm land use diversity and (iii) nitrogen farm-gate balance. Local mixed crop-livestock farms did not have significantly higher overall gross margins than specialised farms but were less sensitive than dairy and crop farms to fluctuations in the price of inputs and outputs considered. Mixed crop-livestock farms had lower costs than crop farms, while beef farms had the lowest costs as they are grass-based systems. Concerning crop management practices, our results revealed an intensification gradient from low to high input farming systems. Beyond some general trends, a wide range of management practices and levels of intensification were observed among farms with a similar production system. Mixed crop-livestock farms were very heterogeneous with respect to the use of inputs. Nevertheless, our study revealed a lower potential for nitrogen pollution in mixed crop-livestock and beef production systems than in dairy and crop farming systems. Even if a wide variability exists within system, mixed crop-livestock systems appear to be a way for an environmental and economical sustainable agriculture.

Nutrient flows in lowland dairy farms in the Italian Alps

A traditional dairy production system is still common today in the mountain environment of the Italian Alps, enhancing the economic valorisation of milk through the production of quality cheese such as Fontina PDO (Protected Designation of Origin), and favouring the agro-environmental management of marginal areas. This type of dairy system depends mainly on summer grazing: farmers set up the farm stock on the basis of the high-altitude grassland areas available. For the rest of the year, the livestock is housed on the farm lowland, consequently reaching high stocking rates. Since grassland areas are limited in size here, animal feeding is largely based on acquired forages. In order to study the environmental sustainability of the lowland farm areas, agronomic management, nitrogen (N) and phosphorus (P) farm-gate balances were calculated for 22 livestock farms in the Valle d’Aosta region. Lowland surfaces show a quite high variability, with an average value of 6.8 ha. An unbalanced stocking rate referred to the lowland is common showing an average value of 5.7 L.U. ha-1, but reaching a maximum of 26.8 L.U. ha-1. Lowland milk production is approximately 1700 kg per L.U. per year, but some farms could reach 3500 kg per L.U. The feed efficiency varies from 1.1 to 4.7 kg milk per kg feed, depending on the farm feeding strategy. The average N farm-gate balance is equal to 75 kg N ha-1. The two main input components are represented by purchased hay and feed, both showing the highest variability between farms. The output data also differ substantially between farms. The manure sold is the most important output component and represents 70% of the total output on average. The P farm gate balance surplus is equal to 6 kg ha-1, but more than 25% of the farms considered show a negative value. The surpluses calculated in this work can be compared with the values belonging to a distribution calculated for bovine farms under different management and environmental conditions in Italy and Europe. They occupy the lower part of the distribution and are similar to those measured in mountains or other extensive environments.

Modelling nitrogen cycles of farming systems as basis of site- and farm-specific nitrogen management

The paper describes a model designed for analysing interrelated nitrogen (N) fluxes in farming systems. It combines the partial N balance, farm gate balance, barn balance and soil surface balance, in order to analyse all relevant N fluxes between the subsystems soil–plant–animal–environment and to reflect conclusive and consistent management systems. Such a system approach allows identifying the causes of varying N surplus and N utilisation. The REPRO model has been applied in the experimental farm Scheyern in southern Germany, which had been subdivided into an organic (org) and a conventional (con) farming system in 1992. Detailed series of long-term measuring data are available for the experimental farm, which have been used for evaluating the software for its efficiency and applicability under very different management, yet nearly equal site conditions. The organic farm is multi-structured with a legume-based crop rotation (N 2 fixation: 83 kg ha −1 yr −1). The livestock density is 1.4 LSU ha −1. The farm is oriented on closed mass cycles. The conventional farm is a simple-structured cash crop system based on mineral N (N input 145 kg ha −1 yr −1). Averaging the years 1999–2002, the organic crop rotation reached, with regard to the harvested products, about 81% (6.9 Mg ha −1 yr −1) of the DM yield and about 93% (140 kg ha −1 yr −1) of the N removal of the conventional rotation. Related to the cropped area, the N surplus calculated for the organic rotation was 38 kg ha −1 yr −1 versus 44 kg ha −1 yr −1 for the conventional rotation. The N utilisation reached 0.77 (org) and 0.79 (con), respectively. The different structure of the farms favoured an enhancement of the soil organic nitrogen stock (35 kg ha −1 yr −1) in the organic crop rotation and caused a decline in the conventional system (−24 kg ha −1 yr −1). Taking account of these changes, which were substantiated by measurements, N surplus in the organic rotation decreased to 3 kg ha −1 yr −1, while it increased to 68 kg ha −1 yr −1 in the conventional system. The adjusted N utilisation value amounted to 0.98 (org) and 0.69 (con), respectively.

A comparison of nitrogen use efficiency and surplus in two dairy farms typologies

Referring to the Destra Brenta district (Veneto Region, Italy) two farming systems were considered: grassland-hay (H) vs. arable land-silage maize (M). Manure and crop products belonged to an internal flow, thus an annual farm gate balance of nitrogen (N) was carried out to determine the nutrient use efficiency (NUE) and surplus by using data from a survey. Surplus was determined as difference between inputs (I) and outputs (O) and NUE as ratio between O and I. The main I was represented by purchased concentrate, on the contrary fertilizer accounted only for low amounts. Surplus per surface unit was significantly higher in M-farms group than in H one (269 vs. 369 kg N per ha; P<0.01). Surplus referred to unit of fat corrected milk was significantly lower in M-farms (17.6 vs.15.6 kg of N per ton of FCM; P<0.01) leading to an higher N-NUE (0.260 vs. 0.278; P<0.05).

Model based scenario studies to optimize the regional nitrogen balance and reduce leaching of nitrate and sulfate of an agriculturally used water catchment

Oxidation of pyrite by nitrate (autotrophic denitrification) was identified as the main cause for sulfate increase in drinking water wells in an agriculturally used watershed, located in the north of Lower Saxony (Germany). Nitrate, which inducts this microbial catalyzed process, is drained into ground water predominantly from agricultural fertilization. The increase of sulfate in the ground water can only be stopped by reducing nitrate leaching into the ground water. To analyze the negative influence of agricultural fertilization on the quality of ground water different fertilization strategies were deducted for an investigated area of 890 ha. Calculated on the basis of nutrient balance of soil surface, the current average nitrogen balance in the investigated area amounts to 91 kg N ha-1 a−1. Farm-gate balance of nutrients is a strong indicator for assessing potential nutrient losses caused by leaching. This indicator shows comparable accuracy to the calculated nutrient balance of soil surface which demands, however, much more data input for calculations. Nitrate concentrations in seepage water in 2 m depth layer of the soil from agricultural fields were simulated with the model HERMES for the whole investigated area (agricultural land + forest). The nitrate concentration in seepage water was calculated for the whole area on the basis of farm-gate nutrient balance as an annual average, which amounts to 14.0 mg NO3–N l−1 (62 mg NO3 l−1). In order to keep the nitrate concentration of the ground water below the threshold value for drinking water (EU-water directive: 11.3 mg NO3–N l−1 (50 mg NO3 l−1) and to limit pyrite oxidation, different scenarios with simulation studies to optimize fertilization measures were developed. Only those scenarios which assured reduction of an average nitrate concentration in the drainage water below 11.3 mg NO3–N l−1 (50 mg NO3 l−1) without profit cuts for the farms were analyzed.

Nitrogen balances at the crop and farm-gate scale in livestock farms in Italy

Nutrient balances are often used to represent nutrient flows and to produce sustainability indicators. A soil surface nutrient budget (at the crop scale) and a farm-gate budget (at the farm scale) were calculated over 41 commercial Italian livestock farms. The objectives were to estimate the N use efficiency of the main farm types using the two balances independently, and to assess and discuss the relationship between the two different budget methods. The N surpluses calculated as a farm-gate balance (FGBS) or at the soil surface scale (CBS) ranked livestock farms in a similar manner. The suckling cow farms (SC) showed the best sustainability, BB (beef breeding) and DC (dairy cow) farms were intermediate, while PB (pig breeding) farms were the worst due to their weaker link between breeding activities and farm crops. The CBS was mainly influenced by the manure input, while the FGBS was mainly influenced by the purchased animal feeding in the PB, BB and DC farms, and by the mineral fertiliser in the SC farms. Other information can be derived from a combination of the N flow quantified in the farm-gate balance and the crop balance; two examples are given concerning an estimation of gaseous losses and of animal N excreta for the different animal categories. It has been concluded that even though N balances cannot be directly used to estimate the actual environmental impact of different farming systems, they remain reliable indicators to help discriminate between different farm types.

Barn balance calculations of Ca, Cu, K, Mg, Mn, N, P, S and Zn in a conventional and organic dairy farm in Sweden

Calculations of flows and balances of plant nutrients in agricultural production systems provide some basic information for the assessment of their long-term sustainability. The objectives of this study were to assess the possible impacts of variations in element concentrations between years and of undefined sinks and sources of elements on the accuracy of balance calculations. A 3-year study was conducted on Ca, Cu, K, Mg, Mn, N, P, S, and Zn fluxes in the barns (subsystem) of a Swedish farm with separate conventional and organic milk production. Our main focus in this subproject was on barn balance calculations, the barn housing only cows. Barn balance for an element was defined as amount of that element in [feeds, heifers, bedding, water] - [milk, manure, urine, calves, culled cows]. The focus was on: (1) variations in element concentrations in the main flow carriers [feeds, milk, manure, urine]; (2) information about element dynamics and flows of dairy farming systems obtained from internal flows of elements in the barn balance compared with that obtained from the flows associated with milk production in a farm gate balance; (3) differences in element flows and concentrations between the organic and conventional farming systems on this farm. Our conclusions were: (1) the sampling methods used had low coefficients of variation and thus pooled samples can reduce the costs of element analyses. However, urine must be thoroughly mixed if less water-soluble elements are to be monitored. Magnesium differed significantly in concentrations between years in all feedstuffs; (2) year-to-year fluctuations in harvest can influence a calculation negatively if calculations are based on annual harvest and not on feed supplied. The barn balance calculation showed a source of Cu, Mn and Zn that would not have been obvious in a farm gate balance. The element content of manure and urine calculated as [inputs - milk] would have underestimated the amount of Cu, Mn and Zn in manure and overestimated the amount of K and N. The Cu analysis showed an example of conflicting goals between short-term welfare of the cows and long-term soil fertility. EU legislation regarding land for spreading of manure is not a guarantee against soil contamination by heavy metals; (3) the differences between the organic and conventional system related more to differences in forage: concentrate and home-grown: purchased ratios, which were typical for the average Swedish farm of each type, and less to differences in element concentrations of the feed ingredients.

The information content of the farm and unit level nutrient balances for the management.

The farm gate balance is well known from the environmental literature. This method is not suitable in every case to show the nutrient load for the environment of agricultural companies that is the reason why unit level internal nutrient balances are applied to express the level of nutrient pollution on the environment. These also help to determine the source of the pollution. With the survey of the nutrient flows within the farm we determine the keystones of nutrient management to control the nutrient load of the pollution sources. On the basis of the results and the controlled data of the unit level internal balances we make recommendations for the most appropriate environmental policy instrument to reduce the nutrient pollution.

Results of 10 years of monitoring nitrogen in the sandy regions in The Netherlands

The effect of policy measures on agriculture and water quality with respect to nitrogen have been monitored on farms in the sandy regions since the early 1990s. Nitrogen surplus on dairy farms decreased by 100 kg/ha (30%) in the 1991-1999 period due to demonstration projects and the implementation of MINAS, limiting farm gate balance surplus. Nitrogen surplus on arable farms has slightly decreased (30 kg/ha, i.e. 20%), probably because MINAS became mandatory for arable farms from 2001 onwards. About 25% of the farm-gate balance N surplus leached as nitrate into the upper metre of the groundwater. The NO3-N concentration decreased in the 1992-2001 period, but the decrease was larger for dairy farms (16 mg/l, 46%) than for arable farms (7.7 mg/l, 30%). Of the decrease in NO3-N concentration on dairy farms, 23% is caused by a decrease in N surplus, and 27% by environmental factors, such as a higher precipitation surplus, more wet soils and more peat soils in the second part of the monitoring period. However, unknown factors are responsible for 50% of the decrease.

Environmental effects of manure policy options in The Netherlands

This study explores the effects of manure policy options for agricultural land in The Netherlands on nitrate leaching to groundwater, ammonia and nitrous oxide emissions to the atmosphere and on eutrophication of surface waters. The implementation of the farm gate balance MINAS at farm level, with levy-free N surpluses in the range of 300 to 40 kg per ha per year, and levy-free P surpluses in the range of 17.5 to 0.4 kg of P per ha per year, have been examined. Results indicate that nitrate concentrations in the upper groundwater are related to N surplus, land use, soil type and groundwater level. On dry sandy soils, the N surplus has to be below 60 to 140 kg of N per ha per year, depending on land use, to decrease the nitrate concentrations in the upper groundwater to below 50 mg nitrate per litre. Decreases of N and P concentrations in surface waters, upon lowering levy-free surpluses appear relatively small. For improving the ecological state of surface waters, we recommend a combination of low levy-free N and P surpluses with dredging P rich sediments, flushing of ditches, and decreasing discharges from other sources.

Effects of animal productivity on the costs of complying with environmental legislation in Dutch dairy farming

Dutch dairy farmers have to comply with two policies that aim to reduce losses of nitrogen and phosphate to soil and ground water. The first policy (Mineral Accounting System, MINAS) uses a farm gate balance approach for registering nutrient input and output and consequently nutrient surpluses. Surpluses above an acceptable level are taxed. The second policy (Manure Transfer Agreement System, MTAS) aims at restricting manure application by requiring a manure transfer agreement for manure that is produced on the farm but cannot be applied according to maximum application rates. A possible way to meet both policies is to increase animal productivity in order to complete the milk quota with a smaller herd. This paper explores the impact of increasing animal productivity on economic results of dairy farms of different intensities taking into account environmental policies and a restricting quota. Furthermore, the yearly costs of extra quota are determined below which it is more interesting to buy extra milk quota in response to increasing milk production per cow than to decrease the number of cows. A linear programming model of a dairy farm is used to examine the economic and environmental effects of improved productivity for three farms differing in intensity. From the results, it appears that an improvement of dairy cow productivity leads to considerably lower costs of meeting the environmental policies. From the economic values (EV) of milk production under the 2003 environmental legislation follows that farms with a low intensity can pay three times as much for additional quota than high intensity farms.

Fluxes of K, P, and Zn in a conventional and an organic dairy farming system through feed, animals, manure, and urine—a case study at Öjebyn, Sweden

One aim of this paper was to present flows and balances of K, P, and Zn at a barn level for an organic and a conventional farming system, and compare the systems with respect to agronomic sustainability. A second aim was to identify internal on-farm flows of major concern for the environment. We define barn balance as the balance between element flows entering and leaving the barn. The flows of potassium (K), phosphorus (P), and zinc (Zn) through the barn compartments were separated between an organically and a conventionally managed farming system. The study comprised 1 year. The area of the organic system was 59 ha and that of the conventional system 45 ha, with 50 dairy cows in each system. Feed, bedding, tap water, and milk were recorded and sampled monthly. The manure and urine were sampled in conjunction with spreading. In comparison with the organic system, the conventional system produced more milk per cow and per hectare, but to reach that target, the conventional system was more dependent on land outside the farm for feed production than the organic system. As a consequence, the total internal flows from feed crop production were larger in the organic system. The concentration of K in organic silage was significantly lower than that in conventional silage. The concentrations of K, P, and Zn in the other materials studied did not differ between systems. The barn balances of the two systems were similar to each other. The study showed a large internal flow of K, equal flows of P, and smaller internal flows of Zn within a dairy farm as compared to the animal-associated flows through the farm gate. For K, about 70% of the total amount in farm feed crops and purchased feed was recovered in recorded outputs. For P the recovery was close to 100%, whereas for Zn, more of the element was found in the outflow than in the inflow. The imbalances of K and Zn represented flows that would not have been recognised in a farm-gate balance, but which could have a considerable impact on soil accumulation, long-term soil fertility, and losses to the surrounding environment.

Potential Effects of Accumulating Environmental Policies on Dutch Dairy Farms

Consequences for farm management, environment, and economics of environmental policies for Dutch dairy farms were examined through modeling with two policies applied successively to typical dairy farms. Both policies aim to decrease nutrient losses in the soil. The first policy, the Mineral Accounting System (MINAS), is a farm gate balance approach that was introduced in 1998. Acceptable surpluses and levies are gradually tightened in this system until final standards are used in 2003. The second policy was developed to comply with the European Union Nitrate Directive and is called the Manure Transfer Agreement System (MTAS). This system links production and use of animal manure. Farms that produce more manure than the amount that can be applied on their own land according to standards are obliged to have a contract with a farmer who is willing to apply the surplus of manure on his farm. This system will be first applied in 2002 and final standards will be used in 2003. Results of the MINAS policy show fine-tuning of protein feeding especially by replacing grass in summer rations by maize silage and low protein concentrate. Another general result of MINAS is decreased use of N-fertilizer on grassland. As a consequence, division of the area between maize silage and grassland is adjusted. Income drop ranges from €1400 to 4800 (5 to 18%). Mineral Accounting System N surpluses drop by 45 to 113kg/ha (23 to 37%). Adding MTAS is an incentive for more grassland as grassland has a higher manure application standard. Particularly for intensive farms, MTAS leads to high extra costs (€2600). However, expected environmental improvement is negligible. Therefore, from an environmental point of view there is no logic in adding the MTAS.